Testing a few digital cables

[manisandher]

Let's put an end to this because we both made out points, I'd say.

Yes, let's.

Mani.

[PeterSt]

I hope this is absolutely clear.

Not really !
Here I thought this about it :

PS: The conclusion could also be that the A/D does not add much. Right ?
Wrong (I misjudged the process).

I stroke that through because of my conclusion that no ADC should be anywhere. But :

I'll have more to say later, but for now I'll just remind you that file 3 went through a 25 year-old DAC and a delta-sigma ADC. It'd be very difficult to attribute the negatives that you're hearing to just the DAC. Of course, easily done if I do the same with a few more DACs, but keep the ADC the same - it's contribution to the sound should become apparent.

And

I would certainly like to 'prove' how good this Sugden DAC is. In order to do this, I need to be able to capture its analogue output accurately. The ADC in the Tascam is clearly not up to the job, but its spdif digital input seems pretty transparent. So I'll be on the lookout for a nice 16-bit linear PCM ADC with a BNC spdif output. Not many of these around, but I've identified a few old DAT recorders that may do the trick.

And

Once (if?) I achieve a close-to-100% ADC capture with the Tascam (I'm working on it) I'll be able to do the same with the analogue output of the NOS1a. I'm really excited about this because we may be able to put all the "I prefer this OS", or "I prefer a higher SFS", etc thinking to bed.

So ... this was all a kind of lead in to today's activities, but ...
Of course I believe you if you now say that in this process no ADC is in order, but to state that all is perfectly clear ?
no.
Mind you, I stroke through my own sentence because there should be no ADC anywhere (also see Title of the topic). And you actually debunked my stroking through. So I have been confused all the way, although I never believed any ADC should be in order.
So for today's activities it is very clear now. But for the general setup (this Topic in general) sure not ...



Possibly you are referring to the ADC only because it is a device (en entity) and it is cable of recording digital data just the same ?

Peter

PS: First thing this morning I made a fairly large post in this topic, all about this question(ing). I ditched it because I was too confused.
So not being really clear is an understatement. Haha.

[PeterSt]

To my ears, file 2 and file 3 are as different from each other as they are from file 1.

Totally agree.
This is why (instead of the large post) I finally aksed wheter that was the vanilla rip.

All I asked was which of files 2 or 3 sounds closest to file 1. Nothing more, nothing less.

Sure. But I can't help myself in changing the subject to the "why" of the #1 being so different then.
Let's not forget (and you seem not to focus on it) that when I listen to #1, I must be listening to the same path of your creation of #3. So all what is in my mind is that I am listening to "double" the #1 path when listening to #3.

Anyway, we have consensus in getting somewhere now.
That is, what we should hunt (and this seems not microRendu stuff if you ask me). We miss something ...

Peter

[manisandher]

I'm deliberately not starting a new thread for this post...

OK, here's the mistake I made. I should indeed have started a new thread for this because it has nothing to do with testing different USB cables, or testing different DACs. It is about testing two different digital transports (the microRendu vs. the Mach II).

Let's not forget (and you seem not to focus on it) that when I listen to #1, I must be listening to the same path of your creation of #3. So all what is in my mind is that I am listening to "double" the #1 path when listening to #3.

Yes, I'm very aware of this.

This is the way I look at it. If the path adds, say, 5% 'distortion', then when listening to file 1, there would be 5% distortion and with file 3, 10% distortion (assuming they're perfectly additive). With 1% path distortion, file 3 has 2% on listening. With 0.1%, file 3 has 0.2%. Etc, etc.

But if the path is truly transparent (0% distortion), files 1 and 3 would sound totally identical.

So the question I was trying to answer is, which digital transport (the microRendu or the Mach II) gets closest to the holy grail of true transparency?

Mani.

[PeterSt]

So the question I was trying to answer is, which digital transport (the microRendu or the Mach II) gets closest to the holy grail of true transparency?

With the #2 (microRendu) it is very obvious that the "colouring" (but translate to give all more body) is caused by distortion. It sounds more "ugly" (I recall that you said similar originally, but already yesterday I could not find that back). Say that the refinement gets lost in the process.
Sadly, with #3 something similar must be going on, but nothing at all points towards distortion. It coincidentally must make right what lacks in the original.
But see ? this is nothing for a thesus. There's no logic in it, nothing. It must thus be regarded as coincidental.

If anything, I would say that the original is smeared and more body is the effect of that - though not for real. So I'd like to think that the body remains the same but that the top end is smeared and thus stops to be profound.

Now we could start thinking whether something like the Mach II is doing such a thing in the first place. So never mind it should not be possible, everything matters and this does too;
we have more bass/body, we have less unrealistic highs, we have more backness (this latter certainly is so in my view) and do that once again and all doubles.
We need two cascaded Mach II's.

By now I think it (indeed) would be best to start out with something that is "better" than the originally uploaded test track. So what I'm hoping for is that I can hear how #3 degrades compared to #1 instead of perceivedbly improves.
That we on a side note (ahum) will also still be able to judge what the mR does in the chain, is a bonus. But I hope that the differences will be more profound *and* that nothing will go against my logic - I really can't deal with that, psychologically.

Btw, I now see that with the not posting of my longer post from this morning, this text was eliminated too and that is a shame :

Interestingly, I think the playing back through the NOS1a makes it more difficult to distinguish between the 3 files.

This very much looks like me today being quite satisfied about many recordings regarding the reality of the drums, while not so long a go there was one measure only : my own recording of the drumkit. This puzzles me. So my own recording has been at 100% right form the start (say 5 years ago) and played back through NOS1 and all from that time, the remainder of recordings (and throughout all my many albums) being at 20-30% or so, while today I wonder whether there's much difference between my own recording and many other albums. One thing is clear : playback (SQ) improved significally since, and my own recording was already at 100% back then (so could not improve).
?

[acg]

Hi Mani,

For what it is worth given the conversation that has followed since I downloaded and listened to those three files, I can certainly hear what yourself and Peter are talking about.  The latter two files are quite different dynamically to the original file, and second in particular is very flat and fuzzy, the kind of fuzzy that I would expect from a cheap dac.  Anyway, the conversation in this thread has moved on but I am still interested to see where this all leads.

Cheers,

Anthony

[PeterSt]

Mani, a question which may appear to be totally irrelevant :

Do you know - or can you see how often those ultra capacitors are beging (re)charged ?
(for others, this is about the mR hence #2 and its by Mani used power supply).

Also, do you take care that the mR PSU is out of the mains when you do all these tests (except for when the mR itself in is under test of course) ? ... this is crucial ...

Thanks,
Peter

[manisandher]

... I am still interested to see where this all leads.

I'll be posting the output from Peter's CD rip a bit later on (once I've done it). Should be interesting.

Mani.

[manisandher]

Do you know - or can you see how often those ultra capacitors are beging (re)charged ?

It's on the CA site somewhere - will have a look later.

Also, do you take care that the mR PSU is out of the mains when you do all these tests (except for when the mR itself in is onder of course) ? ... this is crucial ...

Aha! No I didn't. The Mach II was switched off for the mR test, but the mR was still on for the Mach II test. This time, I will make certain only one is on at the time it is being tested.

Mani.

[manisandher]

Do you know - or can you see how often those ultra capacitors are beging (re)charged ?

OK, here's what John Swenson wrote on CA:

The LPS-1 is designed to be left on 24-7.

The bank switching is done with transistors so there is no noise.

The time between bank switching depends on the out current. For 1A it switches about every 4 seconds. For low current output like a REGEN it is a couple minutes.

So, a very, very low frequency.

Mani.

[PeterSt]

So, a very, very low frequency.

Yes, but it is not about that in the end (I implied it though). It is about the charging time. IIRC the maximum capacity is 2.5A ? Then it could be read something like this :

4 (seconds) / 2.5(A vs 1A) = 1.6 seconds. So for its max capacity it switches each 1.6 seconds, which also is the maximum capacity (per bank) and thus this should imply continuous charging.
I know, I know, this won't be 100% correct because the capacity as such needs not to be equal to the charging capacity, but assumed all has been made in some balance, it will be close to equal.
So :

This means that for a device which draws 2.5A (at 12V I suppose, but this is not relevant) a continous load will be on the mains, which is fine. But with, say 250mA (could be the mR) there's an on/off switching each 10 seconds, where the loading (charging) takes 1.6 seconds again and which will go at the highest current (because the bank will want to charge fast).
I don't regard this to be good because of this changing. But never mind. Point should be (assumed I am a bit correct) that when it is used for real (like when feeding the mR) it will be OK as it is because it is there for a reason. But if it is not used (no music plays but all is under power anyway) then it shouldn't give the "opportunity" to disturb.

Side note (or not) : When I design stuff (or try to ) this is foremost about capacitors, which are now inside of the device and while there for their good various reasons, they disturb just the same (because they charge at "frequency"). This is also why the Mach II has only a small capacitance on its (linear) PSU instead of what you might expect.
Ultracaps are just capacitors hence they charge about as fast (but last like a battery). So in this case (LPS-1) they are exernal and will not be protected by a buffer which normally comprises of ... capacitors (say that these to some degree normally protect from the mains to be 1:1 discharged by the high current spikes a device (like power amp) may imply.
Of course nobody looks at it that way, and this is only looked from the 180 degree other angle : you need capacitors because the mains is not fast enough and also is too far away (which would be true). But also think what it takes for your *other* devices when a very large cap (and ultracaps can be seen as that) need to be charged and which goes by infinitely higher spikes than what your amplifier will ever ask for. Thus, amp asks 10 times for current before the cap recharges, which thus goes by 10 times the current the amp asks for. And might this be about 1:1 then the (buffer cap) design is not right. So ... law.

That was all. But interesting in itself I think. And oh, this is nothing against ultracapacitor power supplies and most certainly not against the LPS-1; my remarks are just general and my own ideas about matters.
Peter

[boleary]

Hi Brian,

File 2: Roon -> HQPlayer -> bit-perfect 16/44.1 output
File 3: XXHighEnd -> bit-perfect 16/44.1 output

Mani.

Don't you assume that there is some equivalency in sound between Roon-HQ/Player and fully tweaked/RAM-OS optimized XXHighend player? If there is no equivalency (I'll bet the family farm there is No Way Roon/HQ sounds the same as XX on your Mach II) how can a valid comparison be made? Wouldn't it be better to play all (microRendu and Mach II) with identical HQ player settings?

[manisandher]

OK, here we go with the Konbanwa track...

1. Peter's original file (flac):

https://drive.google.com/open?id=0B82Qx9VwoovtUGExZWNrVEZfbDA

2. microRendu digital out (wav):

https://drive.google.com/open?id=0B0PU5LO5jVjfNGxheGZFVXFEd1U

https://drive.google.com/open?id=0B0PU5LO5jVjfUUFxcGs3TDFlclU

3. Mach II digital out (wav):

https://drive.google.com/open?id=0B0PU5LO5jVjfdVBwTWlYVDE3ZGs

https://drive.google.com/open?id=0B0PU5LO5jVjfU1NkMXhWZTVUd1k

I won't say anything at this point, other than the shortcomings of digital path are much easier to identify with this track.

So, which file sounds the closest to the original - file 2 or file 3?

Mani.

[manisandher]

Don't you assume that there is some equivalency in sound between Roon-HQ/Player and fully tweaked/RAM-OS optimized XXHighend player? If there is no equivalency (I'll bet the family farm there is No Way Roon/HQ sounds the same as XX on your Mach II) how can a valid comparison be made? Wouldn't it be better to play all (microRendu and Mach II) with identical HQ player settings?

I'm sure you're right. But the point isn't which hardware is better, the point is which digital transport is better, and that includes the software. I've chosen what is considered the best software in each case.

So what we're really comparing is the 'best' microRendu setup vs. the 'best' Mach II setup. I think this is the most interesting comparison, certainly to me.

The whole purpose of this exercise, for me, is to determine whether I can live with the microRendu setup in my office system, or whether I need to set another Mach II up in my office. At the moment, it seems the latter is going to win hands down.

And yet, over at CA, people are convinced that the microRendu/LPS-1 is absolutely as good as it gets...

Mani.

[boleary]

So what we're really comparing is the 'best' microRendu setup vs. the 'best' Mach II setup. I think this is the most interesting comparison, certainly to me.

Okay, I thought you were just trying to determine which transport was better. Once you throw in the software one is left not knowing whether the decrease in SQ with the Rendu is to to the hardware or the software. Would be great if a way could be figured to load XXHighEnd on the Rendu. Or, if you just wanted to judge the transport and not the software, to run HQ player on both devices.