Modifying USB cable to supply 5v

[abraxalito]

Originally Posted by SY

Make it safe and go for 8192.

OK, so bin width will be around 5.4Hz. Now, you were talking about a 50Hz distance between the 'sideband' and the fundamental. What leads you to hypothesize there may be 50Hz modulation components responsible for the audible differences?

[abraxalito]

Originally Posted by J.R.Freeman

Come now, there is no need for hostilities.

No hostilities on my part, after all you did call me 'friend' a while back. I'll just add this 'hostilities' to your list of claims which come with zero evidence...

On the subject of audio signal distortion content I have some personal experience, and have learned from others along the way. I do not doubt that phase noise can be audible, but I reasonably doubt that it is when it is 78 dB below the fundamental (and on the low end of the audio spectrum no less, where our ability to hear distortion is reduced when compared to higher frequencies).

Guido Tent thinks otherwise to you, I'd guess he's got a little more experience - you're arguing from ignorance as you've already admitted. So once again, stretching the meaning of 'reasonably'...

Such subjective data is of no value, especially considering the commercially biased source.

Show your reasoning please. You've already claimed the mod has 'no value' so you're basing this claim on the previous claim perchance?

This same logic is used by proponents of Totem Beaks, to prove their worth.

I have no idea what those are, care to elucidate and perhaps I'll be able to show how the analogy you're suggesting is as broken as your other arguments.

Of course there is.

Yet another unsupported claim Interesting that you request others provide 'proof' for their claims but don't hold yourself to the same standards you set.

If you tell me you've invented a time machine, is it on you to prove it exists, or is it on the world to prove that it doesn't?

If I had, I'm not going to be interested in 'proving' anything about it. I'd be way too busy using it to make perfect (CHF denominated) spread bets on the date of the collapse of the US dollar or some similar activities. How would 'proving' something about it help me or anyone else?

[J.R.Freeman]

Good evening Abrax,

I am not really sure what your main points are, or what you are trying to accomplish. My assumption is that you are in support of this modification, and that is fine with me.

At this point, it would appear, reasonable communication has ended. Perhaps there is a language barrier? Although I do not agree with some of your points of view, I enjoyed parts of our conversation.

To those responsible for this modification and its claimed performance increase: I remain skeptical but open minded. If ever someone decides to post up some proof, I would certainly be interested.

JF

[abraxalito]

Greetings J.R.F.

I think if I had a main point it would be this - savour the irony of you coming into this thread saying the mod's worthless and asking for proof when all along your claim was baseless.

I'm not particularly 'in support' of the modification as I am not aware of the details of it. But I'm certainly in support of pushing the boundaries of our understanding of what's important in digital audio design, and it appears at this stage that jkeny's mod might help in this regard.

You once again use the word 'reasonable' in an idiosyncratic manner, so I'm at a loss to comment on your perception that 'reasonable communication has ended'. I've enjoyed the interaction with you too.

[jkeny]

JF, it's good that you now have an open mind about this - at least something has been achieved. As Abrax said, it's a pity you didn't have this open mind when you barged into this thread & bullishly & unequivocally claimed it was useless.

BTW, I wonder did the O/P ever do the mod & what were his results?

Finally, I don't do this mod in my product - I leave the USB 5V as-is but I do supply a clean, independent 3.3V to the clocks & a separate clean 3.3V supply to the clock handling circuits. All the details of how to do this I documented in a thread on this & other forums. Nevertheless, the USB 5V mod is worthwhile & I advise the O/P to try it - it costs nothing to try.

[SY]

Originally Posted by abraxalito

What leads you to hypothesize there may be 50Hz modulation components responsible for the audible differences?

What leads you to believe that there are audible differences? There MAY be, but as yet, no evidence.

When these shots are released I bet you are going to argue over whether the test set-up was rigorous enough, what the sonic effects of that difference is anyway, & why didn't such & such get measured instead.

No, what I'm asking for is measurements of the results, that is, changes in the analog output. I don't listen to SPDIF signals, nor (I suspect) do you. If there are analog changes, then it's plausible that there could be audible differences.

[jkeny]

Originally Posted by SY

What leads you to believe that there are audible differences? There MAY be, but as yet, no evidence.



No, what I'm asking for is measurements of the results, that is, changes in the analog output. I don't listen to SPDIF signals, nor (I suspect) do you. If there are analog changes, then it's plausible that there could be audible differences.

No, I listen to analogue with an instrument that you also own - ears (we may have calibration differences ).

But, I don't understand your request for the a demonstration of changes in the analogue signal. Surely, if one wants to demonstrate a direct link between a modification & it's change to the signal, one measures the signal at the earliest point possible after the change, not when it has been through pre-amp & amplifier circuitry?

[SY]

Surely, if one wants to demonstrate a direct link between a modification & it's change to the signal, one measures the signal at the earliest point possible after the change, not when it has been through pre-amp & amplifier circuitry?

No, I don't think so. The analog signal is what's important- if it remains unchanged after a mod, then it's highly unlikely that there are any audible effects. If it does change, at least it's possible that the anecdotes describe a real phenomenon.

Let me propose a poor analogy- someone claims that putting nitrogen in their tires makes their car's top speed higher. They want to show this by monitoring pressure changes in the tires with and without nitrogen. Wouldn't it be more logical to just measure the top speed?

[jkeny]

Originally Posted by SY

No, I don't think so. The analog signal is what's important- if it remains unchanged after a mod, then it's highly unlikely that there are any audible effects. If it does change, at least it's possible that the anecdotes describe a real phenomenon.

Let me propose a poor analogy- someone claims that putting nitrogen in their tires makes their car's top speed higher. They want to show this by monitoring pressure changes in the tires with and without nitrogen. Wouldn't it be more logical to just measure the top speed?

You do realise, Sy, that not all sonic changes are currently measurable! Why not use the final arbiter of sound change & exquisite instrument - your ears. I understand your need to have a demonstrable set of measures but you must also realise that the instrumentation is not up to the job - how do you measure sound stage depth, for instance or instrument timbre or sonic tails? Show me an FFT that demonstrates these effects!

You are also going against the scientific principle which is to demonstrate the cause/effect as clearly as possible i.e without other introduced distortions (DAC, pre-amp & amp)

[SY]

You're asking about interpretation of differences. the first question, though, is "are there any differences to interpret?"

So if there's jitter, noise, whatever (and that's what you've claimed), these are MEASURABLE effects on the analog output stream. They are either there or they aren't. It will take you about 15 minutes to get some data. I'd do it except that I don't have any USB devices to hand, and the effect on Firewire and PCI devices that I do have was zero.