USB Cables... again

[manisandher]

Just a quick post to share my latest USB experiences...

A couple of weeks back, I decided that I really ought to try my Berning OTL SET amp with my 114dB/w horn speakers. The amp is a strange design - DC-coupled, no output transformer, switch-mode power supply, etc. It's pretty quiet by SET standards...
- Signal to noise: 92 dB (20 kHz bandwidth)
- Line-frequency hum components: 60 Hz: -94dB; 120 Hz: -100 dB; 180 Hz: -104 dB

... BUT, with my ear fairly close to the MF/HF horn I could hear some 'crackling' noise coming through the speakers as soon as the PC was switched on. And lo and behold, I could 'hear' my mouse whenever I moved it. I could also 'hear' the HDD doing its work. No question about it, this was noise being propagated from the PC to the NOS1 via the USB cable.

A couple of years ago I bought a USB cable from eBay which had separate data and power lines, with the ground passing through the data line (not the 5V power line). I fished this cable out and connected it to the PC via only the data line. Et voila, no crackling noise whatsoever...

... AND, a totally different sound too. A much cleaner, fuller sound, with much deeper bass. On first hearing, it sounds too laid back and almost dull. But with prolonged listening it sounds more realistic. The highs, although more subdued, are sweeter. And the real test is that you can listen to music for hours without any agitation.

[I tried the cable (just data) in my office system too - totally different mobo, CPU, PC configuration, etc, and the change in sound was very similar.]

Not really sure what to make of this. My mobo is the same as the one that Nick has just replaced. It could be that the mobo is cr*p and having just the USB data line connected helps. As to the change in sound... Well, either it's better because of decreased USB noise entering the NOS1. Or it's worse - the USB cable suppressing transients and the like. Will try a few other things and report back.

But one thing's clear to me - even the NOS1 is affected by USB cables and how they deal with noise from the PC.

Mani.

[juanpmar]

Just a quick post to share my latest USB experiences...

A couple of years ago I bought a USB cable from eBay which had separate data and power lines, with the ground passing through the data line (not the 5V power line). I fished this cable out and connected it to the PC via only the data line. Et voila, no crackling noise whatsoever...

... AND, a totally different sound too. A much cleaner, fuller sound, with much deeper bass. On first hearing, it sounds too laid back and almost dull. But with prolonged listening it sounds more realistic. The highs, although more subdued, are sweeter. And the real test is that you can listen to music for hours without any agitation.

Mani.

Hi Mani, this issue of the influence of the usb cable looks interesting. If the NOS1 don´t use the power part of the usb cable I don´t know how the cable can influence the sound (old discussion here in the forum). Anyway could you provide some details of the type or brand of the cable you use?

Best regards,
Juan

[Flecko]

+1. Thanks Mani, sounds interesting.

[manisandher]

Anyway could you provide some details of the type or brand of the cable you use?

It's a 1m Ridge Street Enopias USB cable. I paid USD150 for it from eBay. Apparently, it was >USD1000 new, which is simply crazy. There is very little information on the Ridge Street website about the cable - it looks like they may have stopped making digital cables - it doesn't look anything special. But it has certainly totally killed the crackling noise. Maybe the added change (improvement?) in SQ has nothing to do with the cable's properties (materials, geometry, etc), but rather the separate the data and power lines. Certainly, the NOS1 seems perfectly happy just connected to the data line. But having the ground connected is essential.

Mani.

[Jud]

Would be interested to know what you think of the Mapleshade Clearlink USB Plus, which I use, and Alain did (not certain if he still does).  15 or 30 day satisfaction guarantee (not sure which).

Best I've heard, including one twice as expensive.  What made me think of it is the mention of separating the power leg.  In the Mapleshade, the power leg and the signal and ground legs (latter two twisted together) are loosely held within a sort of open weave mesh.

[AlainGr]

Mapleshade Clearlink USB Plus are still my USB preferred cables I have them between my music PC and the NOS1. I like the philosophy behind it and of course the SQ it provides.

Now I have to run to begins this day will lots of jitter in my precipitation

Alain

[PeterSt]

I added this to that other topic from where you referred to this (and then removed it there). Here it looks a litlle unsollicited, but I think it can be important anyway :


Of course noise still matters; if you add it.
So far I have not seen a situation that more USB noise added "brightness" of any kind. The other way around (soften the sound), mucho. This is no guarantee of course ... only that it would be the first time to see it the other way around. Also, you won't be the first one who is fed up after a week or so with that more blanketed sound (I know, my words). So just keep in touch with it all.
And mind the bass. More bass ? then more noise for sure.


Try the influence of a separate "ground" cable in parallel to your RCA interlinks. Similar things may happen. Whether things change depends on many things. But just saying ...

Regards,
Peter

[manisandher]

Of course noise still matters; if you add it.
So far I have not seen a situation that more USB noise added "brightness" of any kind. The other way around (soften the sound), mucho. This is no guarantee of course ... only that it would be the first time to see it the other way around. Also, you won't be the first one who is fed up after a week or so with that more blanketed sound (I know, my words). So just keep in touch with it all.
And mind the bass. More bass ? then more noise for sure

Hmm... I think it might be the first time then. I getting absolutely the sweetest sound I've ever achieved, I think. Maybe not 'more' bass, but deeper and paradoxically more tuneful.

But will keep on eye on things.

Mani.

[PeterSt]

Mani,

Maybe not 'more' bass, but deeper and paradoxically more tuneful.

After I posted yesterday I realized I always say "more" and this time I should have explicitly said "deeper". But that was only after I heard my own system again ...

As I told in the other topic, I had a small hum coming through the horns which I could solve yesterday. And, gone was the SUPER deep bass. I have created too very lengthy posts about it with all my reasoning how that happened (through the Orelino speaker). Both times I was (too) reluctant to post ... No matter I could not hear colouration I felt it could not be right. And it wasn't. It was impeded by "noise" ...
Still that bass (sub-low) was crazy.

And so I'll bet you it will be wrong. Expecially the combination with "sweet". You really are not the first (if it already wasn't you yourself ??). But we'll see. And if you like it better, well, you just do and why not !

Best regards,
Peter

[manisandher]

And so I'll bet you it will be wrong.

Well, I've just been playing around with a few things this morning and... I'll take your bet!

There is no question in my mind that the sound is better with the power line disconnected. With it connected, the amount of USB noise is simply not acceptable - it's easily audible when the music is playing.

Apart from the USB noise, the sound itself has that 'digital glare' which I believe contributes to 'false detail'. And unlike you, Peter, I'm very familiar with this effect. I used to own an Esoteric D70 DAC (my first introduction to the PCM1704 BTW). It was a very educational unit. You could connect it to the transport in one of three ways:
1) PLL. Initially this sounds very nice, but you soon realise it's 'digital glare' and 'false detail' all over.
2) RAM buffer. The worse. Dead. Totally dead. Yes, just like your 'blanket' description.
3) Word clock (with additional BNC cable). Easily the best. Loads of detail, yet clean and pure.

And the difference in SQ that I'm hearing between using a regular USB printer cable and the split power/data cable is very similar to the difference between 1) and 3) above. I'm pretty certain anyone listening to the two cables would prefer the latter.

BUT there are a few caveats that I should share:

1) I'm using a 5m USB cable extension before the 1m USB cable to the NOS1. My music PC currently sits in my basement. It's a totally silent machine (apart from the HDD), so I'll bring it up to the main room some time and see if shorter USB runs makes a difference. I did experiment with USB cable lengths a while ago and couldn't hear a difference between 5m, 3m and 1m runs. But with my current USB noise issue, it might be worth experimenting further.

2) My mobo may be totally cr*p. Nick found this with his. It could be that the mobo is creating more USB noise than normal. I believe Brian also has the same mobo, but I've not heard him mention anything untoward about the sound he's getting from it.

3) The USB noise has only now become an issue because until very recently I've been using balanced connections between the NOS1 and power amp. With balanced connections, there is absolutely no USB noise, irrespective of USB cable type or length. Indeed, with the Sauermann monos, the only thing you can hear with your ear inside the 114dB horn is some low-level white noise. With the Berning SET, there is noise of certain frequencies, but it's not mains hum - the amp uses a switch-mode power supply. I'm generally against these, but understand why David Berning uses them (for a whole bunch of reasons that he describes on his website). In any event, he's a smart cookie, so I'll assume he knows how to make a proper power supply.

Peter, not sure how to conclude our bet. If you have any ideas, let me know...

Mani.

[PeterSt]

Haha, you changed the rules !
... sort of.

So, first you change "something" which even makes USB noise audible through the speakers, and next ... well, next don't expect jitter to be crazily high as a first thing.
(you have read that John Swenson articles (especially the first part IIRC) so you know what happens with that.

So, true; when you start out with USB noise (somehow) things are the worst. The properties of that are similar (more deep bass, filtered highs) with the difference of the bass being not tight at all. What you have "added" to the situation is that the noise is audible through the speakers. Well, "noise" of whatever source or kind, because USB noise is just one 8Khz (and 16KHz) tone and this will NOT be audible (120-130dB down or so).

If you think you solved this specific issue by means of that power line disconnected (well, that is what you say now), then I will believe that unconditionally. I do *not* believe yet that you don't have USB noise, which is a first thing to present itself when something is wrong in general. But possibly.

In the far end you're talking about a completely different issue. For my part not USB related at all.
And I think (or am fairly sure) what you applied with your USB cable, is not about the USB cable at all. Just another ground connection or cut of that.
But not easy to judge, because when you now way "without power" ... well, wasn't that a possibility in the first place (the NOS1 doesn't need that) with my idea that in the end it works out the same for its gnd connection (as the data line's gnd).

All bets are off now. As long as you can't win (or to ensure that). Hahaha.
Peter

[manisandher]

OK, I'm pretty certain Peter will tell me that I'm doing totally the wrong thing, but I'll go ahead anyway...

I've drawn up my current grounding/PE scheme. I use a 'star arrangement' with a 3m copper chemical rod in the garden. The guy who installed it believes it's around 5 Ohms to earth, based on the clay soil in which it's inserted. In any event, it should be much better and electrically much cleaner than the house PE. (I won't go into details here, but I use 2 balanced transformers - one for the basement and one for the listening room - to isolate this earth from the house PE.) There are actually 12x 3m earth wires connected to the solid copper bus - 6 going into my listening room and 6 going into the basement (I've only shown 5). Now the interesting stuff...

Every component has its PE connected to one of the 12 earth wires. Being of equal length, each of these should sit at exactly the same potential wrt to earth.

Now, in a regular setup, the NOS1 will derive its ground from the USB cable (I'm not talking about the NOS1's PE here - this is derived from 4 and is just connected to the chassis). But the ground is itself derived from the PC's ground plane (which I'm assuming is ultimately derived from the  PC's PE connection, 1).

Now, I'm using a >5m length of USB cable. Everyone says this is a bad idea. I'm not so sure. Pat over at AR-T uses very long lengths to make his spdif cables, to reduce the affect of reflections - at MHz freqs this matters. And maybe there's a case for long USB cables too? But of course the major downside is the susceptibility to RF interference with such a long length. So what I've done is to connect the USB cable's screen at the PC end to earth (2) and at the NOS1 end to earth (3).

But this has now done exactly what Peter wanted to avoid - use the PE for ground in the NOS1. What puzzles me though is that this is unavoidable isn't it? I mean, where does that ground get it's reference from anyway? The PC's PE, no?

Anyway, what I really wanted to talk about was the affect that having 3 connected or not has on the sound. It totally changes when it's connected. It's cleaner with what sounds like a quieter background. It's darker with less 'sparkle'. But along with this, there's much less sibilance and edge to the sound. It's much easier to listen to. 'Blanketed'? I wouldn't say so, but compared to 3 unconnected, it certainly sounds less bright and lively.

Any thoughts as to why connection 3 in my scheme is having such a profound affect on the sound?

Mani.

[CoenP]

You not only referenced to the earth rod but also ceated a new path for currents. Current runs in loops like from pc to dac via 2 and 3 (and back through the usb cable) or via 2 and 1. Etc etc.

Like stiffness in mechanics, the current (like displacement) will yield toward the least resistive (most stiff) path.

And then we have induction: the wires acting as a current generators within ac fields.

Currents all over the place. Some for the better, others for the worse. This is trial, error and learn material.

Maybe a bright guy is able to solve this puzzle... Peter? Anyone?

Regards, Coen

[manisandher]

Reading the John Swenson articles, it's clear that there have to be return currents or things just wouldn't work. But they create ground plane noise. What I'm trying to do is to feed this noise away from the components and into the earth by using a star arrangement to reduce as much as possible any potential difference between components.

Mani.

[CoenP]

Reading the John Swenson articles, it's clear that there have to be return currents or things just wouldn't work. But they create ground plane noise. What I'm trying to do is to feed this noise away from the components and into the earth by using a star arrangement to reduce as much as possible any potential difference between components.

Mani.

John S also talks about the groundplanes being polluted by circuit noise. This means that you have to choose a quietest point on your grounding where you connect the earth reference. If you make multiple refs on the ground you create the possibility to run currents through the ref (aka loops) especially when this is a low impedance path for the noise involved.
So if the pc is refecenced to ground at a certain point and you add another ground reference at the usb terminal you have two referencepoints. My point is that the effects of this are now rather unpreditcable.
I would rather experiment what the difference is between referencing at the pc ground at the plug versus referencing at the usb side.

Since the NOS1 circuitry is internally "floating" I would expect that it is not adviced to ground the poweramp circuitry. You will create a path for currents to pass through the NOS1 (that is that a low impedance path is via the NOS1).

I realise this need more thinking and experimenting.

Regards, Coen

[manisandher]

Hi Coen, I'll back to you once I've tried a few things.

Meanwhile, I've just taken my office music PC into my main listening room and given it a go. Firstly, the 'USB noise' is identical. With a regular USB cable, I can hear the crackling noise. This increases whenever I move the mouse. It's at a level pretty much identical to that of Le Monster. When I use the new USB cable with only the data line connected, the noise is totally eliminated.

I use identical XX settings in both PCs - both have powerful CPUs and 16GB of fast RAM. But I much prefer the sound of Le Monster. This is probably down to the fact that it has a HDD and my office music PC has an SDD. In any event, it looks like Le Monster's mobo is absolutely fine (hope you're reading Brian) and also that my long USB run is absolutely fine.

No doubt it's my amp that's allowing me to hear the noise coming through the USB cable. As I've said before, it's a strange design - DC-coupled, with the ground connected to its PE. This complicates matters of course. I've attached a couple of circuit diagrams for anyone who's interested (good luck with them - they're totally beyond me!).

Mani.

[CoenP]

Just got some more ramblings in my fingertips...

I realise I forgot one important thing and that is the whole point of earth referencing is to NOT have currents flow through them that are generated by the circuitry; it is just creating a "silent" point for your circuit towards all other voltages are referenced. they don't change their relative values. It is what it is: a reference. This is where the refrencing the usb at two points goes astray: the groundrefs 2 and 3 are able to and will carry a signal.

Than there is the matter of radio energy that has a potential to the earth and as such can induce currents in conducting objects (wires, casings etc) to earth, closing the loop from the antenna to ground. So here the ground ref has a completely different function: getting the radio energy out of the circuit (or let it stay in the box... ). For this you only have to ground the casing that contains of the circuitry.

So my common sense says: or wire 1 or wire 2, no 3 and no connection between the case and circuit of the poweramp would be optimal.

Regards, Coen

[CoenP]

Hi Mani,

Hi Coen, I'll back to you once I've tried a few things.

Meanwhile, I've just taken my office music PC into my main listening room and given it a go. Firstly, the 'USB noise' is identical. With a regular USB cable, I can hear the crackling noise. This increases whenever I move the mouse. It's at a level pretty much identical to that of Le Monster. When I use the new USB cable with only the data line connected, the noise is totally eliminated.

This sounds awfully familiar. I had a similar experice some time ago, but I never changed the stock USB cable. I could hear everything from the pc, mouse, hdd, cpu with distinct noise patterns. Annoyingly loud with horns. Afaik i toyed around with pc powercables (with/without PE connected, different powerstrips) and with the cabling in my amp. It is solved but not by usb but either by amp rewiring or powercable optimisation or new power supply(?). Have to remember a lttle harder how I did it...

Afaik the usb powerwire isn't connected to anything in the NOS1, except maybe the spike protection chip at the input of the USB. I'm not shure about that, but if correct noise from there can enter the circuitry.

I've been studying the Berning a couple of years ago. A very interesting, very, very clever design. But you have to realise it works like an AM  radio with the output transformer as sending and receiving antenna. The whole high voltage is modulated at a high frequency at the 300B side. Allways wondered how this works out for RF.

Regards, Coen

[juanpmar]

3) The USB noise has only now become an issue because until very recently I've been using balanced connections between the NOS1 and power amp. With balanced connections, there is absolutely no USB noise, irrespective of USB cable type or length.

Hi Mani, with balance connections you don´t have that noise but any difference in SQ with the Ridge Street Enopias USB cable versus the stock cable using in both cases xlr connections?

Juan

[CoenP]

Hi,

The 5V of the USB cable is internally protected by the ESD protection chip in the NOS1. So it is connected. I can imagine some mechnisms that noise from the 5V line will be entering the NOS circuit, but those will be fairly small.

I toyed around with powercables, powerstrips en earthing (as far as possible here), but the system remains silent in all cases, that is the PC noise (if present) is swamped by the noise of the amp that is allready quite low.

In the time I had a flawed psu that distroyed -according to my measurements and theory- the internal NOS1 ESD protection chip. So I switched PSU to Seasonic X-400 and got a repair from Peter (actually Cisca!). Can't remember ever having any noise problems after that. That is with the regular USB cable.

My hunch is that the noise on the usb 5V is able to enter your NOS1 circuitry as a result of damage. In my view this noise problem could point to a half blown ESD protection chip; the result of one experiment too many (and I also use a tube amp...). I could very well be that my power connection arrangement was the culrpit of the blown ESD chip rather than the PC PSU. Since I am only partially familiar with the internals of the NOS1, it is hard to reason how such a thing could happen and wether it happened to you.

Regards, Coen

[PeterSt]

Maybe a bright guy is able to solve this puzzle... Peter? Anyone?

Not me. Your outlays (also following the post I just quoted from) are quite thorough. It's only that no real rules can be applied because we are not on control of the devices themselves (and how they connect to PE, up to even needing that for some).

USB is just a nasty thing, and I myself don't understand it. This is about how it is organized in the PC which I think is "a standard" and how it runs its gnd over PE as far as I can see.
When the PC is not connected to PE (Protective Earth - your third pin on the mains cord) this is never for the better. Not in my case (all kinds of noise pickup occur, generally only measurable but can also turn into audible noise).

[ I added all sorts of explanations about connections, but it got too complicated so I removed those ]

Now, back to the "Not me" I started out with;

So I have a new set of amps and after some twiggling I was able to have it completely noise free (I didn't measure that, but audibly is enough for me, for now).
In the mean time I am measuring loudspeakers and for that it needs another USB connection to the amplifiers (to program the DSP in there for the bass drivers). So what I have is an audio PC with USB to the NOS1 and USB to the amp. There's another connection through Ethernet to another PC; this is inherently isolated.
No problem anywhere that I can see.

Then I changed the DSP programming from the audio PC to that other PC, because that is more convenient for me. The only thing changed was removing the additional USB connection from the audio PC to the amp, which now changed to a connection from that other PC to the amp.
Both PCs are in the same mains outlet (which is also where all the audio is connected to).

Now I receive a buzzing noise (something like over half of a second) just before music starts, plus when the monitor switches off or on I hear it through the speakers (a small tick). This is just already the "soft" switch off/on implied by software - not the hardware button.
The buzzing noise I also had when there was audible noise through the speakers. I don't know about the ticks. So, solved that noise (XOver filter pickup that was), but now the same is back by my different "USB path".

And now you think that I know how to solve this ?
I can't even reason out where this buzzing noise comes from. Looks like something is hammering on the monitor and tells "shut off man !" and it keeps on doing that until it doesn't respond anymore. The tick too feels like coming from just software usage.
Anyway I can test this by not letting switch off the monitor (I am thinking just now). But still, if that is the source, I would not know a single means to solve it.

And might Brian read this : Brian, that buzz could well be the same you reported about.

I don't think mouse movement causes any audibilities in my situation. However, I am using PS/2 connections for that which is of course on purpose. Mani, you ?

One thing should be clear : this whole sh*t is so complicated that it only lets solve itself by trial and error. A little base knowlegde is a good idea but in the end not enough.
And when all is solved you should regard yourself lucky. The very best thing though would be to have that reference, like KNOWING that your situation can be noise and tick etc. free. Like in my situation. Without that - like years ago - I would not even start looking. "Belongs to it" I would think.

Peter

[PeterSt]

it is hard to reason how such a thing could happen and wether it happened to you.

I don't think Mani is telling that he can't revert to his old situation (with balanced interlinks). So, as far as I read it, a change of topology now lets this happen.

Another thing is that any real balanced situation ("differential setup") like what would happen with the NOS1 connected to the Sauermann amp, forces DC Offset to be 0, hence forces a good ground reference. This may lead (thoug a long shot) to forcing the USB reference into the better just the same.
Ok, must stop here, because otherwise I'm again trying to make a too complicated story full with hallf-truths and uncertainties.

Peter

[PeterSt]

About the ESD protection (I wanted to reply to that yesterday, but forgot) :

So, the 5V USB power is only used for that part of the USB interface. It's a bit of an odd solution perhaps, but as soon as the ESD protection chip is "passed" on the PCB, the USB (5V) power is cut off and goes nowhere. 3.3V is self-generated on the board.
In the mean time, the chip itself should never blow, although indeed that happened to you Coen (and is still the only case we know of).

Peter

[manisandher]

I would rather experiment what the difference is between referencing at the pc ground at the plug versus referencing at the usb side.

OK, FWIW... I've played around with the USB grounding connections under my control, namely 2 and 3 in my earlier diagram. With only the data line of the USB cable connected to the NOS1, here's what I'm hearing:

1) 2 and 3 both disconnected

Very bright, thin sound. Lot's of HF stuff going on, e.g. can't hear the initial strike of cymbals as it's drowned out by too much 'glazed' shimmer. Too much sibilance on voices. Actually, voices don't sound real - there's no three-dimensionality to their edges; they sound like two-dimensional cardboard cutouts. General background is rarely totally 'black' - there seems to be a constant reverberation of some sort or other going on. This leads to the sense of 'extra detail', but I think it's false detail.

Interestingly, I had the music just stop playing mid-track on one occasion - the audio device was lost. Coincidence? Well, it's never happened before when I've had both 2 and 3 connected.

2) 2 connected, 3 disconnected

Better. Things are generally calmer. But there's still an edge to the sound. Leading edges seem to be unnaturally amplified. I start tensing up as I'm listening because I know there will be something screaming out of the speakers as soon as a leading edge (be it a vocal, a piano, an electric guitar, or whatever) comes my way. It's almost as if the music is being unnaturally modulated by the leading edges.

3) 2 and 3 connected

My preference. This simply sounds the most realistic to me. The brightness has been all but totally eliminated, and yet there's plenty of inner detail in the sound, e.g. I can hear the 'rasp' of a sax or the texture of a cello. Voices? Well, well recorded stuff is incredibly realistic - I was shocked at how good Cobain sounds during quieter pieces on my MFSL CD of Nirvana. Is it perfect? No, I don't think so. There's still the last vestiges of sibilance sometimes, but this could be down to the recordings, or even perhaps my mobo.

And to reiterate, all of this is with my 'new' cable using just the data line.

Mani.

[manisandher]

This is where the refrencing the usb at two points goes astray: the groundrefs 2 and 3 are able to and will carry a signal.

Coen, my feeling is that this is a good thing. What we want to do is reduce the return current in the USB cable, as this will only increase the ground plane noise. With 2 and 3 connected, the return current has a much lower impedance return path via the thick (6mm) earth wires.

But hey, this is pure speculation on my part.

Mani.

[manisandher]

This sounds awfully familiar. I had a similar experice some time ago, but I never changed the stock USB cable. I could hear everything from the pc, mouse, hdd, cpu with distinct noise patterns. Annoyingly loud with horns.

I don't think mouse movement causes any audibilities in my situation. However, I am using PS/2 connections for that which is of course on purpose. Mani, you ?

Yep, I'm using PS/2 for both the mouse and keyboard (using 2x 5m PS/2 extension cables, which don't seem to be affecting performance). But moving the mouse is clearly audible along with the more general 'crackling' noise. Of course this is only the case with the USB power line connected and when using the Berning amp (with all its idiosyncrasies). There's nothing, nada, when the power line is disconnected.

Mani.

[Scroobius]

Mani,

Not sure I understand your earthing arrangements.

1. Are the yellow lines actual wires? for example I would expect only one earth wire connected to the PC in the basement. All sorts of "things" inside the PC will be connected to the one earth connection including the USB shield.

2. Similarly do you really have two earth wires (3 & 4) connected to NOS1? again I would expect only one earth wire connected via the mains plug and it would be connected internally to the case of NOS1 only (and not the ground of the electronics board).

Just an observation it seems from the Berning cct diagram that the electronic earth is connected to protective earth. Often there is an earth break resistor in valve amps but that does seem to be the case with yours. What this does mean is that with your system you will always have at least one earth loop. Because Berning amp electronics ground is connected to the earth rod and also connected to NOS1 electronic earth (via i/c) which is then connected back to earth rod via the USB shield. Unavoidable in your system. But if the earthing is as shown in the diagram then there are other earth loops. What happens when you connect / disconnect wire 3 would be totally unpredictable.

Cheers

Paul

[manisandher]

I've been studying the Berning a couple of years ago. A very interesting, very, very clever design. But you have to realise it works like an AM  radio with the output transformer as sending and receiving antenna. The whole high voltage is modulated at a high frequency at the 300B side. Allways wondered how this works out for RF.

I'll put a longer post in my 'Testing a few amps' thread. But for now I'll just say that the Berning sounds as interesting as it looks on paper. Absolutely no softness at either end of the bandwidth. And a sound stage that goes back behind the speakers for miles. The sense of recording space is incredible, especially on classical recordings. I think this is one good test of 'real' resolution. What's this down to? Its SET design? Its single output device design? Or just the fact that tubes have no hysteresis affects? I don't know. But I really like what it's doing to the sound.

Better than the Sauermann, BD-Design or Sanders amps I have? Hmmm... "Different", I'd say. These push-pull SS amps all sound way more dynamic and 'in your face' than the Berning. Also, there's no way the Berning can energise the room in the way these others can. And the BD-Design monos have a clarity that is hard to believe - better than anything else I've heard. BUT... I just think that there's a certain magic with the Berning and the 114dB horns. My hypothesis is that a horn needs to be driven single-ended and not push-pull to sound most natural...

Mani.

[manisandher]

Hi Mani, with balance connections you don´t have that noise but any difference in SQ with the Ridge Street Enopias USB cable versus the stock cable using in both cases xlr connections?

This is more difficult to test as it would require taking the Berning out and replacing with one of my other amps, and I don't really want to do this just now. But in my office system, I use a fully balanced setup - NOS1 going into active Genelec satellites/sub. From what I remember, the Enopias reduced some of the brightness of the printer cable even in this balanced setup. Could be a good thing, or a bad thing. Will need to try again and get back to you.

Mani.

[manisandher]

My hunch is that the noise on the usb 5V is able to enter your NOS1 circuitry as a result of damage.

Well, this is easily tested - I have two NOS1s! I'll take the one from my office and try it in my main room.

Mani.

[juanpmar]

Hi Mani, with balance connections you don´t have that noise but any difference in SQ with the Ridge Street Enopias USB cable versus the stock cable using in both cases xlr connections?

This is more difficult to test as it would require taking the Berning out and replacing with one of my other amps, and I don't really want to do this just now. But in my office system, I use a fully balanced setup - NOS1 going into active Genelec satellites/sub. From what I remember, the Enopias reduced some of the brightness of the printer cable even in this balanced setup. Could be a good thing, or a bad thing. Will need to try again and get back to you.

Mani.

Ok, thanks Mani

Juan

[manisandher]

1. Are the yellow lines actual wires?

2. Similarly do you really have two earth wires (3 & 4) connected to NOS1?

Hi Paul. Yep, and yep.

USB is just a nasty thing, and I myself don't understand it. This is about how it is organized in the PC which I think is "a standard" and how it runs its gnd over PE as far as I can see.

Just an observation it seems from the Berning cct diagram that the electronic earth is connected to protective earth.

It's really because of your observation that I'm doing all this. In the PC, the ground (electronic earth) is connected to PE. In the Berning, the ground is connected to PE. My feeling is that my connections 2 and 3 would reduce ground loops in the USB cable and in the interconnects between the NOS1 and Berning, as there would be very little potential difference (depending on how 'rigid' my star arrangement is) between each ends of these cables.

Again, pure speculation.

Mani.

[CoenP]

This is where the refrencing the usb at two points goes astray: the groundrefs 2 and 3 are able to and will carry a signal.

Coen, my feeling is that this is a good thing. What we want to do is reduce the return current in the USB cable, as this will only increase the ground plane noise. With 2 and 3 connected, the return current has a much lower impedance return path via the thick (6mm) earth wires.

But hey, this is pure speculation on my part.

Mani.

If that is true then:

You don't have to run through the central ground point. A thick wire parallell will do the same thing, maybe better because it will be shorter (less impedance and much shorter loop).

Regards, Coen

[CoenP]

My hunch is that the noise on the usb 5V is able to enter your NOS1 circuitry as a result of damage.

Well, this is easily tested - I have two NOS1s! I'll take the one from my office and try it in my main room.

Mani.

That would definitely exclude the NOS from the picture!

My memory about this issue starts coming back:
I managed to somehow create a short circuit on the 5V in the NOS ESD protection chip. This immediately shuts off the usb ports on the pc and renderes the NOS1 unusable. Awaiting the NOS1 repair I played some tunes through the mobo soundcard, where the PC noises also where very apparent. Same thing happened  when I swapped the PSU to my other completely different internet pc. Using another spare PSU, noises where geatly reduced. The PSU causing the noise was decommissioned.

The thing is I didn't start out with these noise issues. They appeared likely as result of some failure somewhere, the PSU being prime suspect. I cannot exclude the possibility that the fault also partially distroyed the ESD chip making the NOS1 transparent for the noises. The ESD chip could have failed later completely by something else.

This remains speculation, because I never internally examined the suspect PSU nor the NOS1 on this matter.

Regards, Coen

[PeterSt]

But this has now done exactly what Peter wanted to avoid - use the PE for ground in the NOS1. What puzzles me though is that this is unavoidable isn't it? I mean, where does that ground get it's reference from anyway? The PC's PE, no?

The NOS1 doesn't need any ground. It creates it herself. Same with your Sauermann.
And this right away is the danger as well;

Any self-created ground (also named Virtual Ground) will have an exact 0V reference. This is because this 0V is just in the middle of the voltage rails used. So, put e.g. an exact +5V and -5V opposed to eachother, and in the middle is half of that - 0V. Now :

While such a device has a real 0V reference, any other device not doing that will be based on the what it's provided through the mains. This is more difficult to explain, but take it that the 0V reference which is inherently there, is not that once devices are connected. The reference is pulled up somewhat, and the difference in DC you measure will be the difference between NOS1/Sauermann and the device connected. In the mean time a current flows through the connection.

This is where I need to stop, because all further is speculation. But one example, relating to my post day before yesterday about J.S. :
When we would be able to isolate the potential difference, for example by means of explicit isolators, you can see the difference in (DC Offset) voltage between both parts. In my case this showed 56V at some moment, and what it comes down to is that this is the created difference on PE by other devices (which goes into the neutral as well).
I, very personally, think that it is not allowed to have an isolated means on one side only. So think of it :
There's the left part with a reference of 56V. There's a right part (behind the isolation) of 0V. Now we connect that to our amplifier which again is related to the same 56V as our left part. The 0V will fight the 56V and the 56V should drop (never think to 28 because it is current related (this is also about your equal length wires which don't tell a thing for this reason)). So, now our left part references to that lower Voltage ? hmm ... something is looping somewhere, but think oscillate.

The above is not official but is derived from empirical finding to some extend. I had a couple of PCBs made to experiment, and they are able to go into the NOS1 and prove to me that any isolation is not allowed. No no, this is nothing about an upgrade, just proving something in an actually working environment. In the end this is about a practicle case where isolation works all right, but I could find no way to eliminate the mains noise I otherwise can easily do. If I can't so this anymore with the isolation, by case is proven.

If you have two PE references anyway (Mani, you seem to have that) measure the DC voltage between the two. AC Voltage, also OK. I think we have been through this before, but re-do that in your current (pun) situation. You could be surprised.

I should add : Whatever you provide to prevent such loops which in my view *have* to be there (my 56V example) will only make it worse because out of control; it will now go through air to ... something.

Once you can detect voltage between two PE rings, shut *everyting* off. Now there should be nothing (and if not, something is still on or wrong (like transformers not creating 0V). But now switch all on again. Chances are very fair that you won't be able to reach the same voltages you saw before. Or just 0V now.
All you implied was a groundloop to flow through a different path which is related to the sequence of switching on. Or, that you somewhere in the past weeks implied a loop somewhere, which can't be broken anymore (tried a new TV for example).

Peter

[manisandher]

If you have two PE references anyway (Mani, you seem to have that) measure the DC voltage between the two. AC Voltage, also OK. I think we have been through this before, but re-do that in your current (pun) situation. You could be surprised.

OK, I've just taken a few measurements:

1) DC between beginning of 1m Enopias cable shield and NOS1 USB connector shield (my earth 3 connected) = 6mV

2) DC between beginning of 1m Enopias cable shield and NOS1 USB connector shield (my earth 3 disconnected) = 6mV

3) DC between NOS1 USB connector shield and Berning RCA -ve input (my earth 3 connected) = 0mV

4) DC between NOS1 USB connector shield and Berning RCA -ve input (my earth 3 disconnected) = 0mV

Readings 1) and 2) are surprising. Why is there a 6mV offset between the two ends of the Enopias cable's shield? (It's only 1m in length after all.) And does this mean a ~36mV offset between the PC in the basement and the NOS1?

Readings 3) and 4) suggest to me is that my extra earth connection, 3, is not introducing an extra ground loop. But rather it might be channeling ground plane noise away from the USB and interconnect cables. Of course, the converse could be true and it could be adding noise. But based on what I'm hearing, I suspect the former rather than the latter.

I have a voltmeter here and a basic oscilloscope. Anything else I should try to get to the bottom of why the sound is changing by connecting my earth connection 3?

Mani.

EDIT: All the above readings were with my connection 2 in place. Disconnecting this changes things. Readings 1) and 2) jump to 22mV. Again, extrapolating this to the whole length of the USB cable, this suggests a 130mV offset between the PC and NOS1.

So if nothing else, my connection 2 is at least greatly reducing the PC/NOS1 offset. My connection 3 seems to have no affect on this offset.

[CoenP]

A few remarks from my side:

- how about the monitor? Where do you plug it in and how is the earth connected?
I have best results if it is plugged into a different powerreceptable from the pc. The monitors switching psu remains allways connected....

- as I went om inspection in my own house it turned out that I don't have a real earthing since they replaced the incoming water with plastic pipes and a new meter but left the connection to the fusepanel in place. That left me under the impression that I had earthing but it was actually the safety earthingh of the water system  .
Safetywise I have two Ground Fault Circuit Interrupters so no lethal situation arises, however all groundsh&t is shared between devices that are connected to the PE. I just requested a few quotes to get a proper groundbar in place.

Now both the PC PSU and NOS are connected with a common PE on the powerstrip but to no real earth. Measuring voltages across the usb is a little hard, but between pc usb and amp-in they match the NOS1 offsetreadings.

I still am under the impression that most noise is generated by the poweramp and that all other stuff is below that.

Regards, Coen

[Nick]

Hi,

A few notes from measuring round NOS1 and PC chassis ground voltages measured at the USB shield connection points of the PC and NOS1. I currently have standard PE arangemnts (eg no star PE eathing of NOS PC AMPs etc).

Measurements are taken at:
a) USB shield connection at the PC.
b) USB shield connection at the NOS.

Both of these points have low resistance connection to the PC PE connection and the NOS PE connection respectively.

Case 1
With PC turned off, NOS1 turned off, NO USB lead connection between PC and NOS1.
Voltage a) to b) = 0mv.

As expected 0v as both chassis grounds are connected to PE via the mains leads to the components.

Case 2
PC turned on and booted, NOS1 turned off, NO USB lead connection between PC and NOS1
Voltage a) to b) = 10.6mv (eg PC is is now 10.6mv higher than NOS1 PE).

Almost all PCs that I have owned elevate their chassis ground potential with respect to mains PE when the PC is booted.

The oscilloscope trace below is taken between point a) and b) under Case 2 test conditions. This gives some idea of the level of noise that is set up between the PC and NOS1 PE / chassis grounds when the PC is booted.

Mani mentioned being able to hear mouse movement through his speakers. I found that moving the mouse did visibly excite the noise shown on the scope trace, particualy the spikes above the main noise level (in real time these spikes appear relatively random and frequent).


Case 3
PC turned on and booted, NOS1 turned off, USB lead now connecting PC and NOS1.

Voltage 6.4mv (eg PC is is now 6.4mv higher than NOS1 PE).
The NOS Chassis ground connection to the PC via the USB shield is pulling down the PC chassis voltage from 10.6mv to this new value of 6/4mv.

Thoughts.

The PC sets up noise on its chassis ground when it boots and elevates its chassis ground by an average of 10mv but a detailed view shows the type noise that is present below. This must set up a ground loop with some complex noise current patterns circulating. The shield of the USB cable in actually connected to NOS signal earth via a 104kR and 4.7nf capacitor which form a parrallel connection between chassis ground and signal ground (this seems to be normal practice in USB interfaces not just for music devices). This means that the noise that is in the trace generated by the PC can in theory transfer in to the NOS signal ground (I must take some more traces to see it this is actually happening).

Mani’s connection “3” may be presenting a low impedance route for this noise (in the trace below and the associated loop currents) to be lead back to PE before it transfers into the NOS Chassis ground / NOS signal ground.
As Coen points out there is the possibility of EMI pick up in the PE wiring loops which but I could not really guess the effects of these.

Hope this helps.


Nick.

[Nick]

If you have two PE references anyway (Mani, you seem to have that) measure the DC voltage between the two. AC Voltage, also OK. I think we have been through this before, but re-do that in your current (pun) situation. You could be surprised.

OK, I've just taken a few measurements:

1) DC between beginning of 1m Enopias cable shield and NOS1 USB connector shield (my earth 3 connected) = 6mV

2) DC between beginning of 1m Enopias cable shield and NOS1 USB connector shield (my earth 3 disconnected) = 6mV

3) DC between NOS1 USB connector shield and Berning RCA -ve input (my earth 3 connected) = 0mV

4) DC between NOS1 USB connector shield and Berning RCA -ve input (my earth 3 disconnected) = 0mV

Readings 1) and 2) are surprising. Why is there a 6mV offset between the two ends of the Enopias cable's shield? (It's only 1m in length after all.) And does this mean a ~36mV offset between the PC in the basement and the NOS1?

Mani hi,

I just read this again and your question about why there is 6mv over a 1m shield and would this meant that you get 36mv from your basement PC with longer USB lead.

It just clicked looking at the trace I posted above. This is not a steady state offset we are looking at across the cable (or even audio frequency). If this were just DC offset then the resistance (proportional to the length of the shield) would determine the voltage drop. What we are seeing is a ver high frequency noise profile (a wave length of 1 horizontal division in the trace is a 2mhz frequency and as you see the noise is much higher frequency than that). What our volt meters are measuring is the rms value of the noise which in my case is 10mv with out the USB shield connection between the pc and nos1 and 6mv with the USB connection. The USB connection dose allow the NOS1 to effectively "pull down" the amplitude of the noise by connecting it to PE but the impedance of this route to PE is not low enough (being meters long) to completely drain the noise away to the actual protective earth. However your additional connection 3 probably lowers the impedance to PE and helps to reduce the noise amplitude. If you want to see what causes that hard top end sound, I think that scope trace could be the culprit.

If I am right your other PC in the cellar will have a similar USB shield voltage (provided that the ATx psu and mobo produce the same offset (as the PC you have measured) above chassis ground when the PC is booted.

I think things are starting to make more sense.

Nick.

EDIT - a little more thinking and I think this now links into Paul's experience using a star PE setup. Im thinking that just as your additional connection "3" may reduce impedance to ground for this noise, Paul's star earth is possibly doing the same thing at the PC and generally in the NOS1 ?

What would happen if a choke was placed in line with the shield connection between the PC and NOS could the noise be filtered ??? Of course this may help with the noise transmitted over the USB shield but since the PC's signal earth, is linked to the chassis earth, this noise is likely also to be in the USB signal ground wire and possibly the d+ and d- data USB wires. Still it should be easy enough to check these other connections for noise.

[manisandher]

Hi Nick, thanks so much for taking the time to share your thoughts.

I've repeated your readings here. But a couple of points first:

1) On the Ridge Street website it clearly states that the Enopias has its shield connected. But I've found that it does NOT - the type B connector shield is connected neither to the type A data shield nor type A power shield on the other side. I'm not sure if this is intentional, to help remove ground loops between the PC and DAC, but it seems strange to me. In any event, for these readings I've used a standard 1.5m USB cable.

2) I have a 5m USB extension lead between my PC and the 1.5m USB cable. I have ignored the 5m extension cable in these measurements and have taken point a) as the USB type A shield of the 1.5m USB cable and point b) as the NOS1 shield.

Anyway, to my measurements using your cases:

Case 1: 0mV
Case 2: 22mV (22mV at PC)
Case 3: 3mV (22mV at PC)

If I connect my earth connection 2, these become:

Case 1: 0mV
Case 2: 6mV (6mV at PC)
Case 3: 1mV (6mV at PC)

So, my connection 2 seems to be pulling the PC chassis voltage down quite a bit, in much the same way that the NOS1 does. However, in both configurations of Case 3, the NOS1's 'voltage pull down effect' does not extend all the way back along the 5m extension cable to the PC.

Interesting exercise...

Mani.

[manisandher]

The shield of the USB cable in actually connected to NOS signal earth via a 104kR and 4.7nf capacitor which form a parrallel connection between chassis ground and signal ground (this seems to be normal practice in USB interfaces not just for music devices). This means that the noise that is in the trace generated by the PC can in theory transfer in to the NOS signal ground (I must take some more traces to see it this is actually happening).

This may well be why the Enopias cable is having such an affect on the sound as the shield is not connected. What is now not clear to me is how the Enopias is eliminating the noise coming through the USB cable. Is it a) because the shield is broken, or b) because the power line is broken?

Mani’s connection “3” may be presenting a low impedance route for this noise (in the trace below and the associated loop currents) to be lead back to PE before it transfers into the NOS Chassis ground / NOS signal ground.
As Coen points out there is the possibility of EMI pick up in the PE wiring loops which but I could not really guess the effects of these.

I strongly suspect that the differences I'm hearing having my connections 2 and 3 in place have nothing to do with channeling noise away from the NOS1. I mean, they have zero affect on the general 'crackling' noise and the more specific peripheral noises I can hear coming through the speakers. Rather, I believe the real benefits of connections 2 and 3 are in providing a close-to-0V reference across the whole system. Ordinarily, using something like the Sauermann amp, this just wouldn't be an issue. But with the design of the Berning amp, there's an inevitable ground loop across the whole system from the PC to the amp. This cannot be good, with currents running through the USB cable and the RCA interconnects. As I've said before, my connections 2 and 3 should be forcing these inevitable currents through the additional earth wires, and not the USB and RCA cables.

That's how I imagine things working in my head at least. But again, pure speculation really. What isn't speculation at all is that they affect the sound... an in a very predictable and repeatable way.

Mani.

[Nick]

Mani hi,

I think there is some real progress here in getting to an understanding PC generated noise. The debate is really helping to draw together snippets of information and the wider picture is coming into view.

Thanks for posting your measurements of Case 1, 2, and 3 tests.

Was your higher value of 22mv for case 2 measured on you Asus mobo PC system by any chance ?

Interesting about the Entopias cable having a break in the shield ground. I had also tried lifting the USB shield connection at the NOS end some time ago when it became clear that there is coupling within the NOS of PE and signal grounds. I was in mail discussion with Peter and Paul about it, but we all seemed to get slightly different results so I did not post at the time. Now I tend to move back and fourth between lifted and connected shield at the NOS but generally I also experience a cleaner top end with less hash when the shield is lifted which seems consistent with your findings.

The light that has gone on for me is that the USB transmitted noise is not a DC offset or even audio frequency. For these noise types we could expect connections to PE to drain the noise resonably effectively. The noise is however in the MHz range touching the 100s MHz range which means that although it can be attenuated to some extent by grounding at the NOS (about 3db improvment in my case, see our case 2 and case 3 measurements), the impedance of the ground is too high at these frequencies to reduce the noise level with any great effectiveness. I agree with you about your connections 2 and 3, and your measurements really show their effect very well. At these noise frequencies even these low resistance grounds can only help reduce and not eliminate the noise, but there is good correlation between managing the noise down and improved sound !

Of course the SQ changes could still be due to better ground referencing at lower frequencies (audio down to DC) as you mention, so this must be considered. Looking at the noise in the scope trace though, you can really see how jitter in the DAC and resends of USB data could be caused, this would defiantly leading to the hash and hardness in SQ.

Seeing the the problem in this way is leading to all sorts of thoughs on what to test next and how it might be managed which is great. I'v got stuff in mind to look at over the weekend and will post back but I'm wondering now if this could really lead to something.

The USB shield is a supper kick off point. Understanding what is going off on the USB d+ d- and signal earth is next to help understand the overall connection (we should be able to forget the +5 volt USB wire as its not needed by the NOS).

Best,

Nick.

[PeterSt]

May it help ...

You guys - most of the time if not always - ever talk about less harshness or less bright etc., while you will not have seen such a post from me ever. This could mean I am deaf of course ...

But with the greatest emphasis you HAVE to understand that - as far as I can get it through forum posts - you same guys have other problems in the first place. So, with no exception I see you talk about noise through the speakers of whatever kind. And if not, tell me now that this is not so, but prove it please by means of how you solved it.

Of course, you are just hunting for the elimination of "noise" and this is always a good thing. But it really is of no use to eliminate noise in whatever MHz reason as long as the in-band noise is there and possibly at even higher levels. And I don't see how the cause can be the same.

I am not saying that this is all a waste of time, but I do tend to think that it is a wrong subject. It is, as long as you as you perceive this audible noise (which Nick's as a special situation of course).
I should add that in the end I am only glad with these experiments and analysis, so please keep this in mind. However, I see you become obsessed and whatever you will solve, it will not solve the issues you *will* be having. But, might you still think that the noise which is coming through your speakers, and which will be under 16KHz without me listening, is not harmful to the sound, well, then I said nothing. 

Best regards and happy hunting,
(and don't get obsessed)
Peter

[Scroobius]

Peter,

Best regards and happy hunting,
(and don't get obsessed)

Hey come on we all know that the only reason we are all here in the first place is because we are "obsessed" 

Maybe I will start a new thread "HiFi Obsessives Anonymous" and each post must start with "Hello my name is XXXX and I am a Hi Fi Obsessive".

P

[AlainGr]

Ha ah! Finally I know who I am 

Alain

[boleary]

Here's a cable thats a lot cheaper than the Enopias:

http://www.yourfinalsystem.com/component/virtuemart/v4-audiophile-usb-cables/highend-audiophile-usb-v4-cable-1-0m-dataonly-17-21-25-detail?Itemid=0

And a short article on the subject:

http://yourfinalsystem.com/cable-design-f-a-q/147-how-do-data-only-usb-cables-work

[juanpmar]

Thanks Brian, these cables at least have a reasonable price. Do you know someone who has used these cables?

It looks that the USB cable issue is still open...

Best regards,
Juan

[boleary]

Hey Juan, I don't know anyone who's used this cable, but they do have a 30 day return policy. If for a decent price they make them in a 6 to 7 foot length, I'm going to order one and will post here about it.

[juanpmar]

Brian, it looks that YFS has two Data Only USB cable, the Reference and the V4, I think that both are built only of 1 meter length (the V4 is also built of 0,6 m.) so I´m not sure if you could get 6 or 7 foot length. Would be nice to hear from your test if possible.

Juan

[AlainGr]

I have always wondered if a USB cable needed an "ideal" length to be efficient. From what I read about Peter's USB cables, it seems that it does not. On the other hand, someone told me that the Clearlink USB cable needed to be 3 feet, nothing more, nothing less. Maybe the design of that cable requires this, but some others will say that the shorter, the better - like in "the best cable is NO cable"...

Alain

[juanpmar]

This is from YFS web site: "Our Reference USB 2.0 interconnect only comes in a 1-meter length. This is based on the tedious work involved and the extra materials used to make the Reference design. It's not as easy as it looks. Contact us if you have a need for a length longer than 1 meter and we MAY be able to accommodate you. We aren't making any promises but we'll see what we can do."

I personally tested different lengths of the same USB cable, like 0,6m, 1m and 1,20m, and couldn´t see a difference. It looks like the problem is noticeable with lengths longer than 6 or 7m.

Juan

[boleary]

Juan, I'm waiting for their reply regarding the length. Will let you know.

[PeterSt]

It looks that the USB cable issue is still open...

There is no USB cable issue. And if there is, the source of it is outside of "the USB cable".

Hopefully it doesn't sound too confusing, but when I have all right in the general noise department, there is also no USB cable noise issue. However, it is the most easy to imply issues hence to see the USB noise implied by USB transfer. Next you can (indeed and undoubtedly) solve that by means around the USB connection itself. Maybe it works for you, but how to tell it is for the better (and I still did not see it proven that what's perceived as "better" really is, because the worse situation implies more bass and less though blanketed highs - an easy pitfall).

The story will be more complicated I'm afraid, but "stating" that there's a USB issue goes too far. In general sure yes, but with the NOS1 no. And if so, people should (finally) be able to perceive crazy differences in SQ just by replacing the 1$ USB cable for anything else. And I mean normal means of USB cables, and not those with separate (additional) ground wires or whatever, like subject to this topic here.

And of course, everybody can do what he likes. But - and again - what I don't like is stating a general "USB issue". Not until it has been proven there is.
Did I say it in this topic somewhere ? First remove the audible noise from the speakers, which for 100% sure won't be reached by USB cables of any strange kind. Just saying (again) ...

Regards,
Peter

PS: Juan, this for 100% sure was no personal attack. But we must realize that people are talked into obsessions unjustified (not that you started the subject, but you could be a first to be obsessed about something unjustified ... IMO).

[juanpmar]

It looks that the USB cable issue is still open...

There is no USB cable issue. And if there is, the source of it is outside of "the USB cable".

Hopefully it doesn't sound too confusing, but when I have all right in the general noise department, there is also no USB cable noise issue. However, it is the most easy to imply issues hence to see the USB noise implied by USB transfer. Next you can (indeed and undoubtedly) solve that by means around the USB connection itself. Maybe it works for you, but how to tell it is for the better (and I still did not see it proven that what's perceived as "better" really is, because the worse situation implies more bass and less though blanketed highs - an easy pitfall).

The story will be more complicated I'm afraid, but "stating" that there's a USB issue goes too far. In general sure yes, but with the NOS1 no. And if so, people should (finally) be able to perceive crazy differences in SQ just by replacing the 1$ USB cable for anything else. And I mean normal means of USB cables, and not those with separate (additional) ground wires or whatever, like subject to this topic here.

And of course, everybody can do what he likes. But - and again - what I don't like is stating a general "USB issue". Not until it has been proven there is.
Did I say it in this topic somewhere ? First remove the audible noise from the speakers, which for 100% sure won't be reached by USB cables of any strange kind. Just saying (again) ...

Regards,
Peter



PS: Juan, this for 100% sure was no personal attack. But we must realize that people are talked into obsessions unjustified (not that you started the subject, but you could be a first to be obsessed about something unjustified ... IMO).

Hi Peter, I only wanted to say that the controversy (if there is some controversy) on the influence on SQ using different USB cables remains open. Not in the sense of solving the problem of noise but in the sense that different cables produce different sound. The truth is that I have no noise problems, at least I do not perceive it and yet I notice differences in sound with different USB cable, just like I notice differences between a USB2 cable  and one USB3.  This is what I meant when I said that the USB cable issue remains open.

No way I could see it as a personnal attack, we are peaceful people ;-)

PS. Sorry for the errors and faults, I'm writting from muy phone and don't have muy laptop with me.

[PeterSt]

Hey Juan,

I am "working" from memory mostly, and I didn't recall any "issues" from your hand.

Not in the sense of solving the problem of noise but in the sense that different cables produce different sound.

So, I just looked back in this topic to be sure, and I still don't see them. However :

The truth is that I have no noise problems, at least I do not perceive it and yet I notice differences in sound with different USB cable

Now you suddenly (??) write this. So you see ? this is how I feel entitled to not hype-up things (which in my view is about copying other's situations or expressions, which in the end have no merit (to me, and thus I feel that it should not have to others as well - which is just what I am warning for)).

But now your more full sentence (hence better context) :

at least I do not perceive it and yet I notice differences in sound with different USB cable, just like I notice differences between a USB2 cable  and one USB3.

Looks like an easy to write sentence to me, meaning that it can consist of some unmeant "merits". So, I read this as "different USB2 cables make a difference just like using a USB3 connection makes a difference". But is that what you really wanted to say ? Thus ... it is easy to think that a USB2 vs a USB3 connection makes a difference (which it does for logical (because electrical !) reaons), but mind the "connection") and "thus" USB2 cables will make a difference as well, no matter you never tried ...
(oops, this sentence may be hard to understand, sorry)

So, careful here. USB cables are allowed to make a difference (but where is the most clear example including a more or less proper description of it), while a connection means should make a difference. USB2 vs. USB3 is such an example, and USB2 copper vs. USB3 glass is another.

And please stay away from not daring to "admit" that even two USB2 cables on a USB2 connection make a difference for you (because I tend to say they should not, haha), because I can perfectly bear that. It's only that I never heard of such a thing clearly before, where btw Mani's connection (this topic's real subject) also is not about a normal USB2-USB2 (or 3) comparison (that's just about changing ground scheme's IMHHHO).

Kind regards,
Peter

[juanpmar]

Peter, could be my english but I used the word "issue" more in the sense of topic than in the sense of problem and I was not talking only about this topic started by Mani but in general about other topics where we were talking about USB cables in general.
Sorry,  no more battery in my phone...

Juan

[PeterSt]

LOL!

[AlainGr]

No matter what I have tried, I was unable to hear a difference with the few USB cables I tried. The Clearlink plus USB cable is different with its concept and the philosophy behind.

The only moment I felt there was a difference was with AC cables that affected the sound. It added a "halo" around women's voices for a while, before finally settling...

I don't pretend there are no differences. I can only say that for my hearing capabilities (or lack of), I can't really "feel" the difference, but I certainly do not discard what is said about them.

I remember that someone said once that a cable will exhibit differences if it is straighet or twisted !

The link Jud put in another thread (http://www.audiostream.com/content/qa-john-swenson-part-2-are-bits-just-bits) is very interesting for this matter.

Alain

[christoffe]

Here's a cable thats a lot cheaper than the Enopias:

http://www.yourfinalsystem.com/component/virtuemart/v4-audiophile-usb-cables/highend-audiophile-usb-v4-cable-1-0m-dataonly-17-21-25-detail?Itemid=0

And a short article on the subject:

http://yourfinalsystem.com/cable-design-f-a-q/147-how-do-data-only-usb-cables-work

Received the 
YFS USB REFERENCE - DATA ONLY CABLE from YFS today. ( 1m for $390,00 incl. shipping= €305,00)

This cable is a major step forward in SQ performance.

Joachim

[PeterSt]

Ok Joachim. Thank you !

Can you now please describe the changes in sound with all the detail you can come up with ?

Thank you again,
Peter

[christoffe]

Ok Joachim. Thank you !

Can you now please describe the changes in sound with all the detail you can come up with ?

Thank you again,
Peter

Hi Peter,

I'm not finished with all of my reference recordings (99% is Jazz),
but the first impressions are:

Sound is much more analog, MUCH less harshness of the cymbals, less reverberation (especially the mids - piano) in my room, more definition (resolution) in the mids and and highs (delicacy), bass is a little bit more accentuated and tighter,  soundstage presentation improved, resinous of violins improved with more body of the instrument.

This cable is worth any cent/pence.

kind regards

Joachim

[Edit]: The harshness in the highs was emphasized by a  new  poweramp (with a DC offset protection),  which I’m using to omit the preamp now.

[CoenP]

I made a quick and (very) dirty "data only" cable from an existing €1,- one very similar to the one i use normally. i cut the shield and red 5Volt wire at the DAC side of the cable and pried out and cut the red cable on the PC side leaving the shield connected.

Iow:
Shield connected at pc side only
Power line cut at both sides not being able to pick up or transfer noise.

I will report my findings when i have a little more listening time on this cable. I also have a concern for esd safety that I have to reason out.


Regards, coen

[Stanray]

Hi Coen,

I'm very interested in your findings, as this is exactly wat I was planning to do.

I was very sceptically of USB-cable influence on SQ, until last weekend when I compared a 1 euro cable with a "fancy" 10 euro cable and I perceived differences. The latter giving a better imaging (focus).

Regards,
Stanley

[juanpmar]

Joachim, would be great if you could make a cheap cable like Coen´s to compare it with your YFS USB REFERENCE - DATA ONLY CABLE

Regards,
Juan

[boleary]

Woke up this morning a very happy camper: yesterday I received my Data-Only V4, one step down from the reference cable Joachim posted about ($265 for a 2m cable), and, after 5 hours of listening yesterday, I couldn't wait to post about it this morning. Was very surprised to see Joachim beat me to it!

Anyway, after reading Mani's initial post I had to give a data-only cable a try. Not really knowing up from down with electronics I couldn't go the Cohen route so, given the 30 day in home trial I figured it was worth a try with the "Your Final System Cable." I didn't order the reference cable cause I just wanted to hear a cable without a power leg and both the reference and the one I purchased appear to be very similar: both use silver plated copper.

Anyway, the change in sound is very substantial. Though I agree with most of what Mani and Joachim have said about a data only cable, one thing Mani said I didn't experience: here, with the data-only cable, the bass is now less deep but far more natural. I used Eva Cassidy's version of Fever whose intro is bass heavy. A/B-ing with the new cable was a revelation regarding a natural sounding bass. Moreover, for the first time, I was able to play the entire song at ear splitting levels. In the past, once Eva started singing this song I generally switched to a different track or turned down the volume to an unsatisfying level because of the "clangyness" (harshness) of the upper mids. Suddenly that "clangyness" was completely gone. Everything I played last night was a new revelation of natural sounding music. The change this cable has made here is another step in the direction that began with disconnecting the optical drive and was followed by removing the front panel and all associated wiring from the PC, swapping the Corsair PS for the Seasonic, and changing from the ASUS to the ASrock MB. The change is equal to what I experienced with swapping mb's.

[PeterSt]

Joachim and Brian,

Both your posts are equally worth while I think, and then I mean that this seems to lead to a *better* SQ after all.
But, I have to say that your description Brian, beats Joachim a little , were it for the more somewhat technical description which matches better my idea about when USB improves the SQ (compare with Mani's description for fun ).

But now we're in this stage anyway, what about those who (maybe in the far back) just tried to not use the power connection ?
And so, now I mean : what about cutting that from the 1$ cable ? I am pretty sure this by itself has been done before, but I have the idea that this was before the USB3 (NOS1 connection) era.

One more -at least for myself important- notice :
Once it really can be proven that not using the power connection is for the better, which would need to include my own measurement - and no matter it would need a $300 cable, it would even be *logic* that this is for the better.
Hey Nick, you will get that, right ?

Regards and thanks,
Peter

[boleary]

Thanks Peter. I failed to mention that the cable is, in fact, connected to a MB USB3 port. Kevin O'Brien, the seller, says that the cable needs a hundred hours to burn in. Though initially the sound was a bit congested, after several hours it really opened up. I cannot imagine it getting much better, but the system will be left on 24/7 for the next four days!

[PeterSt]

I also have a concern for esd safety that I have to reason out.

I HAVE to add that Coen is concerned for good reason;

When the power wires are not used, the ESD safety protection on the USB interface will have vanished. So please notice that this (through normal USB cables) connection has been explicitly applied by me and that I found this more important than even ever trying without and possibly see better (noise) results. But low and behold and see how things come together theough a couple of posts :

Coen had is ESD protection blown once. Reason : some shortcut at the amplifier side. Only two weeks back there was another case of this, with the exact same reason.
And while Joachim is in this topic anyway : Joachim, you too experienced similar (well, reason unknown) but that was with the old NOS1 (non-USB) interface. All I can add to this that I still have a couple of emails about again amplifier "strangenesses" which blew the fuses in the NOS1, right ?

Now guys, please don't ask me where the currents will all flow to -and without blowing fuses first - when you eliminate the ESD protection. So know what you are doing, and when things turn out badly it can really imply a lot of $$$ to repair it.

Finally, a post like this feels a bit strange to myself, because I am all in for bette SQ again and when I finally seem to see it can happen through different means of USB apliance now I need to seriously warn you ? So I'm afraid Yes.
This already now (USB power out) counts for disconnecting/connecting the USB cable.

Peter

[PeterSt]

I cannot imagine it getting much better, but the system will be left on 24/7 for the next four days!

Brian, if breaking in really is in order, then open the NOS1 Driver Control Panel and let that be when you're out or sleeping etc. Putting it to the Taskbar is OK.
This way USB streaming will be active all the time, which is the same as playing.

Regards,
Peter

[CoenP]

Anyway, the change in sound is very substantial. Though I agree with most of what Mani and Joachim have said about a data only cable, one thing Mani said I didn't experience: here, with the data-only cable, the bass is now less deep but far more natural. I used Eva Cassidy's version of Fever whose intro is bass heavy. A/B-ing with the new cable was a revelation regarding a natural sounding bass. Moreover, for the first time, I was able to play the entire song at ear splitting levels.

A very quick first impression of my cable tweak: this does NOT work.
Like Boleary the whole soundstage sounded a lot "lighter", but with a pinched midrange and cymbals piercing needles in my ear. Gone was the magic sound i was experiencing before. Not good.

knowing myself audiowise: there is no cure for a bad first impression.

With the old cable much more wood and chestiness in voices and instruments. You can hear a piano is a wood and metal instrument. The music is really captivating. Well no punishment to go back.

This is all too quick in my view. This needs a second chance.

So I reconnected the screen at the DAC side. Well this sounds ok now, lighter but agreable. I will dive into the sound a little deeper tonigt.

Probably there will be some break-in involved so no definite conclusions for now.

Regards, coen

[boleary]

Brian, if breaking in really is in order, then open the NOS1 Driver Control Panel and let that be when you're out or sleeping etc. Putting it to the Taskbar is OK.
This way USB streaming will be active all the time, which is the same as playing.

Thanks Peter, won't put more wear on my tubes!

[christoffe]

I also have a concern for esd safety that I have to reason out.

I HAVE to add that Coen is concerned for good reason;

Coen had is ESD protection blown once. Reason : some shortcut at the amplifier side. Only two weeks back there was another case of this, with the exact same reason.
And while Joachim is in this topic anyway : Joachim, you too experienced similar (well, reason unknown) but that was with the old NOS1 (non-USB) interface. All I can add to this that I still have a couple of emails about again amplifier "strangenesses" which blew the fuses in the NOS1, right ?

Now guys, please don't ask me where the currents will all flow to -and without blowing fuses first - when you eliminate the ESD protection. So know what you are doing, and when things turn out badly it can really imply a lot of $$$ to repair it.

Peter

Peter,

Over the time the Swedish USB2 cable causes strange readings at the NOS1 VU meters and blown fuses for 2 times, and initiated some shutdowns of the new poweramp (with a very fast reacting DCC offset protection) too, and so I went back to a shelf cable. The shelf cable shows no electrical anomalies at the VU meters (after a PC closing down) anymore (and no power amp shutdowns since then) and the SQ was nearly identical to the previous Swedish cable.

After reading  Brians post about the YFS cable …………… . At present I hear that the acoustic bass (from Brian Bromberg) has a smaller body, less low resonances, but very pristine (nearly identical to Brians impression). The definition of the music improved a lot, more fine details.

http://www.amazon.com/Wood-Brian-Bromberg/dp/B000FQJPBO/ref=ntt_mus_ep_dpi_5

[CoenP]

Hi,

About ESD safety: I see no reason for immediate concern after studying the esd protection chips datasheet.

The chip povides esd protection on +,- and 5v lines. So even when you cut the 5V wire on the cable, the NOS1 is still protected against esd on the 5V pin (and of course on the other pins) of the USB receptable via the traces of the USB board.


Still:

The matter of unexpected currents over the 5V line remains and it is not known what happens to these currents when the 5V wire on the cable is cut.
Please be aware that this no-powerline approach may backfire one day.

Regards, coen

[christoffe]

Joachim, would be great if you could make a cheap cable like Coen´s to compare it with your YFS USB REFERENCE - DATA ONLY CABLE

Regards,
Juan

Hello Juan,

sorry, I do have some skills in gardening and  assembling rough mechanical parts, but not ............. .

Kevin from YFS gave me the advise to buy the reference cable, because .............. .

I'm not quite sure how to proceed after Coen's remarks in his last post. What can happen. Blown fuses "only" or other severe damages (chips)?

kind regards

Joachim

[CoenP]

I my case with connected shield and powerline, the esd chip was blown. Iow the 5V protection was short circuit to ground. Somehow a current from the pc to the NOS1 ground was created. Cause onknown. At first I thought about the pc, but it was more likely that the nos1 amplifier had something to do with it. So far i did not investigate this any further. I have the habit of disconnecting the NOS1 when i do something to either the pc or amp.

Regards, Coen

P.s you need special equipment and some precision skills to repair the board.

[christoffe]

I my case with connected shield and powerline, the esd chip was blown. Iow the 5V protection was short circuit to ground. Somehow a current from the pc to the NOS1 ground was created. Cause onknown. At first I thought about the pc, but it was more likely that the nos1 amplifier had something to do with it. So far i did not investigate this any further. I have the habit of disconnecting the NOS1 when i do something to either the pc or amp.

Regards, Coen


P.s you need special equipment and some precision skills to repair the board.

Thanx Coen,

ok, following your procedure of disconnecting .........,  the best SQ is what we are looking for.

No risc, no fun. (It  might happen, that I have to go to the post office in the near/next future)

Joachim

[manisandher]

A couple of years ago I bought a USB cable from eBay which had separate data and power lines, with the ground passing through the data line (not the 5V power line). I fished this cable out and connected it to the PC via only the data line. Et voila, no crackling noise whatsoever...

... AND, a totally different sound too. A much cleaner, fuller sound, with much deeper bass. On first hearing, it sounds too laid back and almost dull. But with prolonged listening it sounds more realistic. The highs, although more subdued, are sweeter. And the real test is that you can listen to music for hours without any agitation.

Since trying this, I have changed my mobo. Right now I am using a cheap off-the-shelf 'regular' 5m USB cable between the PC and NOS1. I have no 'crackling' sound whatsover.

I haven't tried expensive Ridge Street Enopias cable with the new ASRock mobo for a couple of reasons. Firstly, I would need to use a USB connector to connect the Enopias to the 5m cable, and I don't want any additional USB connections between PC and NOS1 - working at the MHz range, reflections at these USB junctions may cause changes to the sound (this is pure speculation on my part, but it's been proven by Pat at AR-T in spdif cables). Secondly, I'm perfectly happy with the sound I'm getting from the PC/NOS1 combo now. The old mobo really was fatiguing to listen to (something both Nick and Brian found also) and I suspect the 'improvement' in sound I described above was down to the Enopias taming this somehow.

Mani.

[PeterSt]

Sadly it is so complicated and everything seems to be involved.

But thank you Mani for the (even repeat) of this feedback.
I hope it is clear to everybody that bass can not vanish by means of proper grounding (noise !) - only add up (unjustified).

More bass = less straight "waves" = lower frequency because of less frequent modulated frequency.
Especially the higher frequency noise influences jitter in a "muffling" way.
Too sharp highs sadly is also an exhibit of jitter spectra we don't like, so it rally is difficult. But the leaner the bass the less jitter in general (but which also involves ringing of any form (this also spreads the straightness of the wave)).

That the bass may be too lean is quite something else. This just needs "woofer surface" (opposed to Bose milk packs).
That in the mean time highs may come across as "sharp" can easily be implied by wanting "volume" out of the bass. You now just turned up the volume too high to accomplish that.

Did I say it is difficult ?

Ok, enough for now.
Peter

[CoenP]

I made a quick and (very) dirty "data only" cable from an existing €1,- one very similar to the one i use normally. i cut the shield and red 5Volt wire at the DAC side of the cable and pried out and cut the red cable on the PC side leaving the shield connected.

Iow:
Shield connected at pc side only
Power line cut at both sides not being able to pick up or transfer noise.

I will report my findings when i have a little more listening time on this cable. I also have a concern for esd safety that I have to reason out.


Regards, coen

This experiment is over.
No general improvement in sq, an unpleasant haze and ticks during playback gave away the flawed implementation. Error counters went through the roof after a couple of hours playing. No fixing applicable here.
Goning back: no errors whatsoever with the normal cable.

The strange thing is that sometimes it suddenly sounded real good only to disappear soon after, often in the same track. I did not discover any reproducable structure in this phenomena.

Regards,  Coen

[juanpmar]

Joachim, have you experimented the same kind of problems as Coen with his "dirty" cable?. I mean, have you had any problem with your YFS USB cable, or you find that it works fine and the music is sounding as good as when you tested it for the first time?

Regards,
Juan

[christoffe]

Joachim, have you experimented the same kind of problems as Coen with his "dirty" cable?. I mean, have you had any problem with your YFS USB cable, or you find that it works fine and the music is sounding as good as when you tested it for the first time?

Regards,
Juan

Hello Juan,

I did not face any problems until now, and the SQ is better than before. The YFS cable remains in the system.
I'm not using any tweaks for the MB (which is at least 3 years old) within XXH, minimize OS only.

Sincerely

Joachim

[juanpmar]

Thank you Joachim, I appreciate your opinion.

Best regards,
Juan

[CoenP]

It cannot harm to look at the errors in the NOS1 driverpanel allthough you will probably find nothing there. I think my execution was too poor. Also I suspect the cut screen to have more to do with the errors than the cut 5V wires.

Regards, Coen

[AlainGr]

It cannot harm to look at the errors in the NOS1 driverpanel allthough you will probably find nothing there. I think my execution was too poor. Also I suspect the cut screen to have more to do with the errors than the cut 5V wires.

Regards, Coen

Hi Coen,

When you did this (cutting the 5v), how was XXHE reacting when you loaded it ?

I ask this, since with the use of the Sotm USB 3 PCIe card, I can either have the 5v switch turned ON of OFF. And when I forget to turn it ON the first time, XXHE does not see the NOS1... Only after I have loaded XXHE, then I can turn the switch OFF...

Alain

[CoenP]

Hi Alain,

I cut the sleeve of the cable at the beginning and end. Pried out the 5V and cut it at both sides. So no 5 V at the NOS whatsoever.

I have not tested the cable when turning the nos1 off and on. It is allways on. The driver has no problems recognising the nos1. It should not matter since the 5v line is only connected to the ESD chip for safety.

Mayby you have a different nos1???

Regards, Coen

[AlainGr]

Hi Cohen,

Well that is beyond my knowledge (if I have a different NOS1 or not)... But each time I forget to put that switch ON (5v), XXHE brings a window (2 consecutive windows in fact), indicating "No sound card"... So I shut XXHE, turn the 5v switch ON and restart XXHE. My NOS1 is almost ON all the time... Maybe I shut something in addition with what Minimize OS does, so that could explain this, but I am not savvy enough to put my finger on it...

Regards,

Alain

[boleary]

Well after leaving the PC on with the XX Driver control panel streaming for four days I had another good listen last night. Doesn't seem that the sound has changed much, if at all, since the initial 10 to 15 hours of break in. What is clear though is that this cable has finally eliminated a certain HF hash that has been part of my XX experience since 2009. The hash, or as I like to characterize it, clangyness, usually manifests with female voices that suddenly go from 0 to 100 mph in a split second, or with solo violins its heard as the absence of the mid range which is so opposite from hearing them in a live setting. Since I joined the XX community, it seems that every version of XXHighend, as well as every PC iteration and tweak I stole from ya'll has, to some degree impacted this HF hash. Usually, when a change was made its benefits would be apparent and, for a while, that's all I'd hear. Then as time passed, the bad would again re-emerge so that one could hear how the sound was bettered by the change but it was still not quite "right." Well, here in my modest system, that hash has disappeared and, in its absence, music now emerges like never before: woody, natural, live performances with everything I play. Is it perfect? Logically I know it just cannot be and perhaps I'm still only hearing the good and cannot yet hear the bad. But this is among the very most significant changes that I've experienced since 2009. It's like when I switched from my old DAC to the NOS1. It certainly feels like the disappearance of that HF hash is the result of the removal of the PC power leg of the cable.

Of course it is concerning that this cable eliminates the ESD protection. Perhaps, if the merits of this cable design are accepted by he whose mind is unchained from such trifles as "knowledge,"(Move over Buddha, here comes St. Peter!)  a new means of protection will be developed. 

[CoenP]

Of course it is concerning that this cable eliminates the ESD protection. Perhaps, if the merits of this cable design are accepted by he whose mind is unchained from such trifles as "knowledge,"(Move over Buddha, here comes St. Peter!)  a new means of protection will be developed. 

For the record: esd protection of the usb is still working as designed with and without the usb power cable.

Maybe the good sound is due to the lack of the 5V wire or maybe it is about a superior design and implementation of the others. I am glad this works for you!

Regards, Coen

[boleary]

Thanks Coen, but I'm a little confused. Does the lack of a 5 volt wire pose any kind of risk?

[PeterSt]

Brian,

A while back (2-3 months) you told about briefly some "noise" coming from the speakers when you pressed Play;
Has that gone by this ? (or did it vanish earlier because of other reasons ?).
I ask, because I'm sure I could imply the same a while ago (external grounding issue somewhere).

Peter

[boleary]

It vanished earlier for unknown reasons. It was a quick short buzz just before music began to play.