Totally 


"Khan is depicted as a North Indian Sikh—"Khan" is a title; his parents are from Chandigarh, Punjab, India..."

Marla McGivers: "From the northern India area, I'd guess. Probably a Sikh. They were the most fantastic warriors."

My parents were (when they were alive) Sikh. And I have to say that Khan is the weirdest Sikh I've ever seen.

Back to USB to PC chassis ground...

Mani.

I've been using the original (i.e. with inner tubes) Townshend 'siesmic sink' isolation platforms and stands for years. Apparently, vibration is isolated from 2Hz up with attenuation at 20dB per octave. Not sure how that compares with Peter's contraption. There's still airborne vibration from the speakers to the DAC/amp chassis to contend with though, which is true in Peter's case too, I assume.

I currently have my PC sitting in the basement (not right under the listening room, but down and across). When the music is on, I can hardly hear it down there. I wonder if taking the NOS1 down there would make a difference. Haha, I could even stick the NOS1 in a Faraday cage I have down there, but the ICs would then have to be ~8m long. You know what, I'm tempted to try this...

Mani.

I suspect it must have been Leo with this then:


Mani

PS. Hey, this is a nice game when you're stuck in an airport lounge.

Ahh, so it's THE COLOUR OF THE CHASSIS!!! I just knew blue was wrong.

I think we can assume that it has something to do with the 9V battery... or lack of.

Mani.

The biggest problem is the colour of the chassis. Obviously it should be white, and not blue.

Where's the DC meter battery cable???

(As an aside, I really don't like USB-USB adaptors - I know that USB is not an RF transmission line, but it still carries MHz signals and these sorts of adaptors, adding potential reflections, just cannot be a good thing... in my totally-ignorant-on-the-subject opinion.)

Mani.

The only time I've heard anything like 'white-harp' was when I bought a 'Mana Acoustics' platform for my CD player many years ago. They used the resonance characteristic of thick glass sheet to almost tune the sound to 'white-harp'.

So I think the riddle/tweak has something to do with the pink foam pads that come with the NOS1 as 'feet'. (I have a set of pink and a set of white pads. Hey, maybe the colour makes a difference???) Did you buy a particular thickness of double-sided sticky tape to attach them somewhere on the NOS1 chassis? Or maybe using them to isolate/dampen the USB connectors at each end?

Haha, back to the colour idea. Did you buy a specific colour of foam pads? Don't tell me - was blue the best colour?

Well, you did say 'ridiculous'!

Mani.

Hi Peter, I'm currently working away from home but can give it a go when I get back over the weekend.

Mani.

Yeah, of course.

But others might find it interesting to Google these names. There's a lot of interesting thinking out there, but it's all over the place. Actually, this forum is probably the best collective knowledge on the subject that exists. If a better one does exist, I haven't come across it. But would be happy if someone pointed me to it.

Mani.

Matan Arazi?

How clued up is Amir Majidimehr in this area nowadays?

Mani.

Jussi Laako (Miska) maybe? But I'm not sure how much he bothers about noise from the PC, etc.

Maybe Damien Martin?

Hmmm...

How much do the guys at companies like RME, Lynx and Merging really know about all this stuff, I wonder?

Mani.

OK, I'll have another crack. There's a guy on CA called Juergen  (JR_Audio) who posts very seldom, but seems to know what he's talking about. Here's an interesting thread where he was more-than-usually active:

http://www.computeraudiophile.com/f6-dac-digital-analog-conversion/universal-serial-bus-industry-standard-cables-connectors-and-communications-protocols-between-computers-and-electronic-devices-link-da-converters-10292/

I've got quite a few other names to hand if I'm still wrong ;-)

Mani.

Haha... I'll believe it when I see it!

No. I will always keep one NOS1 totally standard and totally untouched. Of course, I will compare the modded to the standard with the new speakers and decide which I prefer.

But thanks for the warning.

Mani.

Yes, I know you're trying to mimic the effect with Q3, 4 and 5. But the Dexas might still be doing something else too, no?

Anyway, once I get my modded NOS1 back from Paul, I'll be able to play around with the various Q-settings and see if I can replicate the Dexa-clock effect totally using the non-modded NOS1, simply through software. Again, this would be superb if it were possible.

Quick question Peter. Is it actually possible to take some measurements of the affect of Q3, 4 and 5 on the USB data transmission? Just wondered.

Mani.

I guess you're referring to Pat at AR-T then? Though it's not just theoretical with him - he actually measures everything. I had some really 'interesting' email exchanges with him a few years ago. I learned so much. "Spdif (rca) is cr*p. AES/EBU is cr*p. 'Scientific Conversion' transformers are cr*p. Only true 75 Ohm spdif (BNC) is any good for MHz transmission. No-one else knows what they're doing. Most AES members are idiots." Etc, etc. Haha... brings back memories.

But the proof of the pudding is in the eating - apparently Pat's Legato II USB-to-spdif converter has 0.05pS of RMS phase jitter from 10Hz to 100KHz, with phase noise measured clean down to 0.01Hz.

Of course, if I've got the wrong guy then totally ignore what I've just said.

Mani.

I don't really have the time to write in as much detail as I would like, but I'd like to share my experience of visiting Paul's (Scroobius) place earlier this week.

A few weeks ago, I asked him to take one of my two NOS1s and change the clock to a Dexa (and power supply). He completed this last week, and on Tuesday this week, I took my other unmodified NOS1 to his place to hear what the Dexas are really doing.

The standard, unmodified NOS1 sounded great, of course (using the mobo's USB3 port). [As an aside, I have to say that Paul has really hit gold with the rest of his setup - it's very, very impressive, especially the LF performance.] The 'clean', 'clear' sound of the NOS1 that we've all come to love is there in spades.

We then switched to the Dexa-modified NOS1 (using a Dexa-modded PCIe USB3 card in the PC). It became clear to me immediately that some sharp edges had totally disappeared from the sound. I wasn't really aware that they were there until we switched. The sound took on a 'wholeness' that is hard to explain. Much easier on the ear. Sweeter. But still totally detailed. It's almost as if the sound was 'pixelated' before and became a lot less pixelated with the Dexas. I had a strong preference for this sound over the non-modded NOS1 sound.

There is no question in my mind that Nick and Paul are onto something here. The Dexa clocks clearly change the sound of the NOS1 for the better IMHO.

But I feel there is one caveat though: Paul cannot use the Q5=1 setting in XX1.186 without his PC locking-up. I haven't played around with the Q-settings enough to comment, but it could be that Peter is able to replicate the effect of the Dexa clocks through software. This would obviously be brilliant... and a lot more convenient for us all.

As a final comparison, we switched to Paul's own NOS1. This has the Dexa clock and power supply mod (exactly like mine) but also has a bunch of Black Gate capacitors replacing many of the standard caps in the NOS1. OMG! The bottom end just 'explodes'. There's oodles of LF energy that is simply not there with the standard caps. A grand piano now has the presence that it does in real life, and no longer sounds like a small upright piano. I don't want to go into any more detail describing Paul's NOS1 because there may be some controversy here about changing the caps in the NOS1, but I will say that I preferred the sound of Paul's NOS1 to both my Dexa-modded NOS1 and to my standard NOS1.

Just wanted to share...

Mani.