Try some different USB ports. I know on MacBook Pro laptops the rear left USB port will not function without dropping USB audio frequently. This is caused by a design flaw that puts the keyboard the this USB port on the same BUS. The keyboard goes to sleep ever so many seconds and when it wakes back up the audio drops out.

As strange as it sounds a USB port is not a USB port.

Excellent idea!

In the back of my mind I knew this, but it did not occur to me to try. Good thinking.

Thanks!

Elk-

You might read this and think "ya, of course I did." But have you restarted?

Very reasonable suggestion.

I am one of those that always turns a computer off when I am not using it. Thus, mine get rebooted regularly.

But this is an excellent suggestion and an option we all forget on occassion. Amazing how a reboot can solve many issues.

Now if I can figure out a way to reboot my brain without hurting myself . . .

I've always thought of sleeping as a Reboot and defrag for the brain all at once. Just the right amount of "drink" gives me that defragmented feel the next day.

I reports this info by AQVOX :

Thank you.

Unfortunately I have tried using an ASIO driver and it has not solved the problem. But there is some very good information in the link you provided!

Have you tried different software as your player? Have you uninstalled/reinstalled playback software? What changed between the time that it was sounding good and now? Any new programs or hardware installed? Any changes in the preferences? Have you tried rolling back the computer to the time when it was working well?

Have you tried different software as your player?

Y-es, including Foobar (with and w/o ASIO)

Have you uninstalled/reinstalled playback software?

-Yes

What changed between the time that it was sounding good and now? Any new programs or hardware installed? Any changes in the preferences?

- Nothing that seems to have an impact.

Have you tried rolling back the computer to the time when it was working well?

- Actually, yes. In fact, I went back to the original ghost image. Oddly, it still does not sound good. Yet everything works great on the other computers I ahve.

- I have additionally tried to determine if something is generically wrong with the USB hardware and/or drivers and there appears to be zero issues.

- I'm stumped. It really doesn't matter as I have other alternatives (including an optical S/PDIF). But I would love to know what happened and how to resolve it, if only for the intellectual satisfaction.

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It really doesn't matter as I have other alternatives (including an optical S/PDIF).

S/PDIF connection from the PC to your Grace DAC works? Have you tried decreasing the volume using the control in your player? I know this is a bad practice for good fidelity but you mentioned in the first posting that it sounded like hot digital audio. I'm very curious about this too. Be sure to post whatever you find is the solution.

Yes, the optical S/PDIF works fine. It is an output integrated in to the motherboard as part of Intel's HD Audio. (As an aside, the 1/8" analog stereo jacks sound amazingly good and I bet the 7.1 is good also- pretty cool for integrated audio).

I have tried turning the volume down thinking that perhaps the level was somehow compromised. Of course, it shouldn't be "too hot" but it was worth checking.

This is such a strange issue.

Elk,

If your ghost image was working at the time of backup and not after it was restored then the problem is lower than the OS. So its either the BIOS or electrical.

The BIOS is easy to check:

Make sure the USB BIOS settings are correct for the Grace.

(High speed vs Full speed info here http://arstechnica.com/news.ars/post/20031003-2927.html
)

If that didn't fix it then either you have a ground loop through your digital connection or the motherboard is bad.

There is a discussion on ground loop problems on another thread. One quick suggestion is to lift the ground pin on one or both(all) the Grace and the computer(peripherals).

Your motherboard may be bad especially if it is new. Have you tried other peripherals on the USB ports?

Scott

Thanks, Scott.

Audio data is very limited bandwidth as far as a computer is concerned. USB 1.0 is more than fast enough for 16/44.1

Yes, everything else that connects via USB works great. The MoBo otherwise seems happy and happily tolerates CPU and memory overclocking (not being a gamer I leave the graphics card alone).

Overclocking? Aha.

Bandwidth is not the issue here. Timing and sync is.

You might want to try NOT overclocking and another USB soundcard. If its not a ground problem then its likely one of these is your culprit.

Good luck

Actually, after playing with overclocking I left it at stock. The extra heat isn't and loss of some longevity is not worth it.

the problem certainly could be timing/sync. I would then expect that the integrated optical S/PDIF would also have the same problem, but it is fine. Thoughts?

I haven't thought of putting a card in. I will look in my supply of extra cards and see if one happens to ahve a USB out. Good idea for trouble shooting purposes.

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I would then expect that the integrated optical S/PDIF would also have the same problem, but it is fine. Thoughts?

IF the problem is a ground loop it would disappear when using optical. (no ground potential in glass)

A timing/sync issue is much more difficult to quantify but you may get interesting results if you put a USB hub in the mix. This MAY get you a measure of isolation, re-clocking and additional ground path.

I

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