Cool, just set out which here - links will do fine, and show your reasoning. Otherwise its just another claim.
I didn't got quite that far, I said I doubt it is necessary. Judging by the numbers of people who have heard improvement though there is certainly something going on.
I agree with my countryman (I should be flying the Union Jack, not Stars and Stripes) that the question has moved to why?
Not to upset the manufacturer of the unmodified hi-face I'm leaning to something off with the existing suppression too, it certainly appears to tie to the growing data set. i.e. That in this specific case there appears to be benefit by doing such a mod, but I'm still of the position that in general if the gear is adequately designed then the amount of effort to do the mod would far outweigh and perceived gain.
If you believe that your statement that if someone believes there to be an improvement that something is better then it's unnecessary to justify it further then sorry, That's utter tripe.
We're not discussing faith systems here, we're digging into electronics used for audio. The first step to there being empirical evidence is repeatability of the change and it's impact. Looks like we have that down, now we're back to "Why?", because it really shouldn't make a difference.
I agree with my countryman (I should be flying the Union Jack, not Stars and Stripes) that the question has moved to why?
Not to upset the manufacturer of the unmodified hi-face I'm leaning to something off with the existing suppression too, it certainly appears to tie to the growing data set. i.e. That in this specific case there appears to be benefit by doing such a mod, but I'm still of the position that in general if the gear is adequately designed then the amount of effort to do the mod would far outweigh and perceived gain.
If you believe that your statement that if someone believes there to be an improvement that something is better then it's unnecessary to justify it further then sorry, That's utter tripe.
We're not discussing faith systems here, we're digging into electronics used for audio. The first step to there being empirical evidence is repeatability of the change and it's impact. Looks like we have that down, now we're back to "Why?", because it really shouldn't make a difference.
Are these the Z100A regulators shown on Paul Hynes' website? If so, how physically are they mounted to get close enough to the DAC chip itself? The pics show they're huge! I can't see any smaller shunt regs on that site.
I see he quotes 2mohms output impedance across the audio band but with the wire length needed to connect to one of these, that figure goes straight out of the window.
Are these the Z100A regulators shown on Paul Hynes' website? If so, how physically are they mounted to get close enough to the DAC chip itself? The pics show they're huge! I can't see any smaller shunt regs on that site.
I see he quotes 2mohms output impedance across the audio band but with the wire length needed to connect to one of these, that figure goes straight out of the window.
From a U.K. DIYAudio and RG member in the U.K. :
"http://www.paulhynesdesign.com/page2.html
Some of the regs are not shown on the site, I think they are new
Heres what I fitted
1 x Z1A-3v3 positive shunt regulator which supplies main 3.3v and onboard Crystek 80mhz XO
1 x PR3G-1v2 positive series regulator supplying Sabres core and VDD1.2v
2 x Z1703v3 50mA positive shunt regulator supplying the Sabres left and right AVCC (VREF)
1 x Z1A-15 150mA positive shunt regulator set to 150mA supplying the +15v of the IVY I/V stage
1 x Z1N-15 150mA negative shunt regulator set to 150mA supplying the -15v of the IVY I/V stage
I personally am very pleased with the results, they needed a few days to run in but the improvements are more than noticeable."
See also a photo at reply 524
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Briefly,
With an analog signal transmitted along a line, any noise introduced to that line rides on the actual signal, distorting it. For a digital signal, as long as the bits can still be decoded correctly at the other end, the noise has no effect. If the noise is substantial enough, it could change the state of a given bit. This would have to be a great deal of noise, however.
The 5 volt supply provided with the USB port is designed for this application, and is more than adequate.
Here's a good place to start:
Digital electronics - Wikipedia, the free encyclopedia
I do not think it is that simple. The USB/SPDIF convertor contains crystal clock and jitter of that clock is dependent on quality of its power supply. And time precision (jitter) is an analog variable.
Did you not read what I wrote above? - the USB 5V is used by the Hiface & internally regulated down to drive the on-board chips & clocks. If you are saying that the quality of the PS to these chips & clocks makes no difference to the sound quality then I'm afraid we occupy different universal views of electronics!
Nobody said anything about the noise on the USB cable that the parallel "dirty" USB 5V might impose on the USB signal carrying wires - although it might be an issue even though the USB receiver id differential & "should" reject any overlaid common mode noise (this does depend on the USB receiver). However there is another aspect of this that you might ask yourself - what is the USB cables impedance specification? How well is this achieved with 4 wires in the USB cable? What effect does this have (if any?) on the USB receiver? Do you know the answers or is "bits is bits" a sufficient answer for you?
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I agree that providing a cleaner, more well regulated power source to an oscillator may improve its stability. However, this device likely employs on-board power conditioning to ensure the power supplied to the oscillators is within acceptable specifications (as dictated by the manufacturer of the oscillators). If the power supplied to a clock is a safe margin above acceptable, the precision of the clock source itself is the limiting factor.
All that to say I do agree with you in that 'good' power is needed. But it seems very unlikely that the USB port power isn't good enough. Logically, the onus of proof is on those making a claim to the contrary.
If good enough is what you settle for in audio, then that's fine - most people are looking for something a bit better than "good enough". There is nobody offering any proof one way or the other - just simply answering the O/Ps question & let him decide! It's a simple experiment to do for oneself!
It's not about stability of the PS, it's about noise on the PS to the clock - look it up!
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Well, I do not know about quality of USB port power. But I do know that on my combination of Envy24 soundcard + TAmp powered by +12V from the PC I can hear every letter printed on screen in a terminal (listing text files makes nice buzz
), every move of mouse, every seek of hard drive. CPU supply is VERY noisy.Of course, no need for proof.
With digital however, good enough = perfect.
It seems there are commercial interests at work here. Let us agree to disagree. That being said, a word of caution to those considering this mod: the USB port power has had to meet standards, and is quite stable. There is a chance this mod could degrade performance of, or even damage the device, if the DIY supply is not as carefully engineered.
But in the end, it is all about learning and having fun. So all the best!
JF
Yes, its all about learning & having fun - that's why people are bothering to try & correct your false idea of digital audio. Remember there's timing involved in digital audio - which brings it into the analogue arena - you didn't seem to pick this up or understand it when Phofman said it!
Let the O/P try the 5V mod or better still RF attenuators & report back - it's DIY & all about getting the best sound afterall?
Let the O/P try the 5V mod or better still RF attenuators & report back - it's DIY & all about getting the best sound afterall?
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Confident, aren't you? But not so confident as to put your claims up to the test. If you can hear the difference, I suppose that is all that matters.
Well, I do not know about quality of USB port power. But I do know that on my combination of Envy24 soundcard + TAmp powered by +12V from the PC I can hear every letter printed on screen in a terminal (listing text files makes nice buzz
Well that's an entirely separate issue, the insides of a computer are antagonistic to HiFi audio. It's only recently that manufacturers have started to care at all about audio quality. Microsofts standards for Windows Logo certification are prety week, but they're a start. What you're describing would fail even their testing though.
Are you totally sure that the noise is coming over the power lines and not caused by RF emissions inside the case, incorrectly suppressed noise on the PCI bus or even improper earthing of the whole thing?
Did you build the machine from parts to a spec, or to a price point?
If it was bought as a complete system then I'd say you have grounds to grumble at the manufacturer if the card works just fine in another system.
Confident, aren't you? But not so confident as to put your claims up to the test. If you can hear the difference, I suppose that is all that matters.
So do you agree that there is an analogue realm to digital audio or do you still claim "bits is bits" in digital audio?
I have with/without battery scope shots of the SPDIF output but they can't be released yet!
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I do. It was certainly considered, however, in both the USB standard, and the design of the digital audio device in question. Power supply noise is simply not as important as it is with a purely analogue device. It's all well and good to say there is a difference associated with this magical mod, but without evidence to back it up, it is all here-say with no value.
So you've studied the design of the Hiface, have you? Please tell us your findings - how is the PS configured on the PCB? What measures are used to suppress noise? Please tell, I'm all ears!
It seems we are going nowhere here. I look forward to your test results, should you decide to post them.
All the best,
JF
OK, now what was the original question again? Oh yes, maybe the O/P will try it & report back or has he been frightened off?
BTW, they're not my test results but a reviewer's - I'm sure you'd have some question marks about me doing them You will probably have some comments about the scope shots when they're published but as they say in some parts of your country "c'est la vie"
BTW, they're not my test results but a reviewer's - I'm sure you'd have some question marks about me doing them
You will probably have some comments about the scope shots when they're published but as they say in some parts of your country "c'est la vie"The noise is not so loud, it takes the volume up and no signal. But it is noticeable. It is not grounding (no humming), RFI either. The card is medium quality - Audiotrak Prodigy 192, it did the same with presumably decent ESI Juli. It is clearly noise on those +12V power lines taken out of my PC feeding the amp, caused by internal chips working in bursts in the moments of activity. It is kind of similar to some MBs making instant noise when the CPU is loaded - noisy inductors in the step-down regulators for the CPU.
I am just trying to show the power lines in PC are very noisy and it makes sense to assume the same about +5V USB lines fed from the PC.
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