Chris hi,

I feel your pain or should that be vibration . At least were not neighbours, I say this only because the spark system on the car used to make so much RF when I bought it that it would freez the picture on any televisions nearby. I wouldn't have wanted to add RF problems to the truck related wows of a fellow audio enthusiast.

Update

I should have siad the above is with 44.1khz material with 8X arc prediction playing through the NOS1 and 4X arc prediction playing via NOS1 SPDIF in to the AN4 DAC.

Perhaps this is just attenuation compression ?

Nick.

Mani,

Your about note dul sound is interesting.
I don’t have the transparency of a very good head phone setup but I think might have something like this as well.

Generally I can’t play direct to amp without pre-amp at the moment, so I use XX at 0db vol and an in amp volume control to set my listening levels. Quite a lot of the time I have to limit the output from my NOS1, so in order to do this I set XX volume to -3 to -6 db to reduce output signal levels.  With XX at -3 to -6 db I also seem to have the dul sound. I would say dynamics drop markedly and performance becomes quite flat.

There could well be other factors in my system that might be contributing to this, however the difference is quite noticeable and is present with both NOS1 alone and NOS1 => SPDIF => AN4 DAC replay chains. The TVC volume control in my amp does not really change the characteristic of sound at +- 6db levels.

I put this effect down to signal compression caused by -3 to -6 db of XX attenuation so never thought to mention the change in sound. But reading your note I though I would replay these experiences just in case it’s of any use to Peter.

I’ll do some experiments with / without arc prediction and peak extend etc.

Regards,

Nick.

Peter,

I was looking out of interest to see if the LP is a direct to vinyl disk mastered recording and came across this.

"The trio recorded four albums: Portrait in Jazz (1959); and Explorations, Sunday at the Village Vanguard, and Waltz for Debby, all recorded in 1961. The last two albums are live recordings from the same recording date, and are routinely named among the greatest jazz recordings of all time."

(Quote from Wikipedia on Bill Evans 1960 recordings http://en.wikipedia.org/wiki/Bill_Evans)

It seems the recording is generally very highly rated, its still amazing how this could be captured so well in the very early 1960s.

Nick.

Peter hi,

Your Subaru is defiantly something of a car, I have seen what they can do on tracks and I'm a big fan!

Unless the engine is not running in my car a stereo wouldn't be much use ,on long runs I use ear plugs . The Chevy V8 sound track rivals listening to a NOS1 though when i'm in the right mood  

The sound system haha 

Uploaded with ImageShack.us

Peter,

Thanks for your kind words,

The fun for me has been that as I was trying to sweat a little extra performance from the Juli@ interface, you were working on similar design decisions on  your entirely new interface. So we have had some fun conversations about clock power supplies, regulators, and various low noise supplies.

I want everyone to be in no doubt though that our conversations really touched only on aspects of tuning your new interface. From what I know the new interface you have come up with is truly inspired in its conception and daring in it’s execution. I just don’t know how you do it, but I am very glad you do. I cannot wait to give it a try.

Kind regards,
Nick

Peter,

All is out now, and way, way more mouth watering than expected !

There was me making evolutionary changes to the Juli@ interface and you were up to your usual revolutionary approach again 

Please put me down for the upgrade as soon as you have capacity.

Best regards,

Nick.

Paul hi,

It’s great to hear how things have gone so far. I know what you mean about not noticing gainclones they just passed me by whilst I was spending loads of time working on my AN P4s. They are great fun aren’t they and the costs relative to manufactured alternatives just keep me  .

A quick tip, in the Peter D’s kit there is an input resistor 200 Ohm I think. It is fine to bypass this (if you have not already) and it’s very well worth doing. Just put a link across then (a 5 min job) and take a listen.
I completely agree with your view of sound, I think of them as super “accurate” sounding  valves in the mids but with low end extension/control and very sweet highs. They don’t sugar coat the sound though, so if the source is not absolutely spot-on you seem to hear everything, both good and bad.

You have me smiling about your much loved 300Bs, I haven’t powered up my much loved P4’s once since I got the gainclones going. It’s not to say that the P4s aren’t really great amps but I just love the gainclones.

When you get time the bi-amping is really worth going for. I was very surprised at the difference it made. In my setup I have two clones per channel running from a 300va R-core per channel, works great and dead easy to setup this way all in one case.

Regarding them not being as relaxed as your ANs this may turn out to be an asset in the end. With the changes I have been trying on the NOS1 they REALLY shine and I have a sound now that is supper detailed whilst being relaxed and not fatiguing. I would describe the gainclones as very “honest”.

The last change to the NOS only happened today but it’s real hum-dinger, and dead easy to apply (it takes about 15 mins). I am waiting for Peter to come back to me but I am quite confident it’s based on sound theory and it is simple to understand what it is doing. It really suits the transparency of gainclones, I will keep you posted.

Kind regards,

Nick.

Sorry again for the teaser, but another change post.

Change 5 is applied. It is a really very simple change indeed, just the removal of a few components but it is by some margin the most profound change so far. A game changer in its own right and can be applied on its own. It changes the whole presentation, bass to highs, the effect on bass is simply great, taught full and deep delivery.

Details are with Peter.

Nick.

ps I don't want to have these posts come across wrongly, it's great fun making these changes but its only possible to get these effects because they are applied to such a great starting point...the NOS1.

Peter,

I see, so the resolution settings available are determined by the OS, meaning a 1ms increment in XX is not possible.

Good to hear that we experience the effect of the settings in a consistent way.

Nick

Peter hi,

In my current setup I am using SPDIF out on my NOS1 quite lot and finding this quite sensitive to XX Clock Resolution settings.

I am moving between setting of;
10ms - Slightly less detailed more pronounced bass
and
5ms - clear highs and with less pronounced bottom end

I suspect the best setting is somewhere in-between these points for my configuration.

Would it be possible to change XX to allow Clock Resolution to be set in 1ms increments ?

Thanks,

Nick.

Hi paul,

Peter's suggestion of serial configuration with input gainclone driving two output gainclone is an interesting one. I have not tried it myself but I can say that the NOS1 driving two gainclone in parallel (per channel) works very well. I have used the NOS1 connected directly (volume control by XX) and via my TVCs with no problems.

I'm guessing you'll get a good result with your AN-Es. Will you build the gainclone if you go ahead ?

Nick.

Paul,

A decidedly low tech contribution to a complex subject  .

A few years ago when I lived in a different house that had PE bonding to the copper water system, I noticed that bonding points were a little corroded so I went round and cleaned and tightened up all of the live and neutral ring main connections and cleaned and tightened the earth bonding points. At the end of the exercise the was a definite audible sound improvement. I guess your dedicated audio ring main would be relatively new and would not be a candidate for this, but its interesting that such a simple measure helped so much.

Come to think of it, I'v not done this in my current house, maybe a job for the week end ....

Nick.

Peters findings have helped here.

I was defiantly suffering from “bad day sound syndrome”. Sound could be very different (relative to what I know could be delivered), to the point that I would try to listen and then just turn off and come back later to see if things had improved. The last couple of weeks things have been stuck in a rut with poor sound most of the time...very frustrating  .

Almost all of the system has been powered until now from one double wall socket, with only one of the active subwoofers being powered from a wall socket across the room. At the wall outlet both sockets were in use with a couple of 4 gang extension leads in series to get reach and sockets to the right locations. The PC, Monitor, DAC, Amplifier, second active sub and a linear power were all plugged in sort of randomly depending on what was being done at the time. This is not quite what Peter is describing I think, if I understand correctly in Peters house there may be use of PE in separate ring mains / wall sockets / supply phases ? Anyway there were some relative earth voltages between components in the range 0 to 15mv.

Out came the old 4 socket extensions and everything was plugged into a single 8 socket extension using only one of the wall socket points. The active sub on the other side of the room still uses a separate socket but this does not seem to drive additional PE voltages. The result is that the relative earth potentials have dropped to between 0 and 0.5mv, and the sound seems back to normal    I have not done many system power cycles so it may be that bad day sound comes back but there was certainly an easily detectable change when the 8 socket extension was connected.

Thanks Peter for posting your thoughts and findings it has made quite a difference, I hope it proves to be a long term solution to bad day sound.

Nick.

Peter hi,


One idea but mainly questions.

Reading you first post the only connection from inside the DAC to the outside is the PE which goes from the DAC power socket into the mains cable but is not connected to the household PE at the wall socket.

Could the 2 meters of PE wire within the mains lead running parallel with the live and neutral leads be coupling the noise. Reading a few papers recently (as you know) there may be capacitive noise coupling between the live / neutral and PE wires within the mains cable. There could be more coupling here to mains noise than say from air borne RF. Could this be injecting the noise ?

• Does the noise still happen with no mains cable connected to the DAC ?
• What happens to the DAC noise if you connect a cable in the same way but with no PE inside the cable (ie just a two core live and neutral cable)?
• If the 3 core mains cable length is varied (eg the PE to live parallel run is varied in length) does this inject more / less measured noise ?
  

217v does sound like a lot of sag its more than 10%, could there be something on your distribution spur (external to your house) that is dragging down the supply voltage and injecting supply noise ?

Nick.

ps Is the plot your mains wave form or an air bourn noise trace I am not clear ?