Steve,
I don't necessarily disagree with any of your comments, and I don't assert that the hypothesis I offered is anything more than speculative, but the "huh" in your last response tells me that my hypothesis may not have come across clearly.
The OP in the thread I linked to early in this thread was using a newly purchased Windows 7 laptop, and experiencing severe distortion, and also intermittent skipping, when outputting audio via USB into a DAC. The same setup had worked fine previously, with a different laptop running XP.
The problem was fixed when at my suggestion he changed the power management settings within the Windows 7 control panel such that the MINIMUM (as well as maximum) "processor state" was set to 100%, instead of the default 5%.
That change in effect disables SpeedStep, causing the cpu to run at its maximum speed all the time. As I say, it fixed the OP's problem with distorted USB audio. Therefore it seems to me to be at least a semi-plausible hypothesis that SpeedStep could, with some computers and in some setups and with some DAC's, cause noise and/or jitter issues that would be sensitive to processing requirements, and therefore conceivably to data format. Particularly if those processing requirements load the cpu lightly and therefore intermittently.
Again, that is just a speculative hypothesis, but in the absence of evidence to the contrary one which seems to me to have at least some degree of plausibility.
Best regards,
-- Al
I don't necessarily disagree with any of your comments, and I don't assert that the hypothesis I offered is anything more than speculative, but the "huh" in your last response tells me that my hypothesis may not have come across clearly.
The OP in the thread I linked to early in this thread was using a newly purchased Windows 7 laptop, and experiencing severe distortion, and also intermittent skipping, when outputting audio via USB into a DAC. The same setup had worked fine previously, with a different laptop running XP.
The problem was fixed when at my suggestion he changed the power management settings within the Windows 7 control panel such that the MINIMUM (as well as maximum) "processor state" was set to 100%, instead of the default 5%.
That change in effect disables SpeedStep, causing the cpu to run at its maximum speed all the time. As I say, it fixed the OP's problem with distorted USB audio. Therefore it seems to me to be at least a semi-plausible hypothesis that SpeedStep could, with some computers and in some setups and with some DAC's, cause noise and/or jitter issues that would be sensitive to processing requirements, and therefore conceivably to data format. Particularly if those processing requirements load the cpu lightly and therefore intermittently.
Again, that is just a speculative hypothesis, but in the absence of evidence to the contrary one which seems to me to have at least some degree of plausibility.
Best regards,
-- Al