Hi Roger,
I would think that if you install a different ic that fixes the problem, you should be all set. Probably what would be happening is that the different ic would have a lower shield resistance, which would essentially short out the ground offset between the components it is connected to, and thereby reduce the extraneous ground currents.
My own philosophy about power distribution is to connect everything in the system to the same dedicated ac outlet, that is isolated from everything else in the house (refrigerators, air conditioners, etc.). I do that to avoid the very type of problem that you are describing.
But I'm probably in the minority among those who focus seriously on power distribution. Most people put purely digital components on separate dedicated runs, to prevent cross-coupling of digital noise into analog signals. It's probably debatable as to whether a dac is a digital or an analog component. I would consider it to be analog, to prevent its outputs from being contaminated by noise from digital transports and other purely digital things.
Many people also put their power amps on separate dedicated runs, because of their large and fluctuating current requirements. But as you appear to have found, that creates the risk of ground offsets relative to the preamp.
I guess the bottom line is that some experimentation and trial and error tends to be necessary.
Regards,
-- Al
I would think that if you install a different ic that fixes the problem, you should be all set. Probably what would be happening is that the different ic would have a lower shield resistance, which would essentially short out the ground offset between the components it is connected to, and thereby reduce the extraneous ground currents.
My own philosophy about power distribution is to connect everything in the system to the same dedicated ac outlet, that is isolated from everything else in the house (refrigerators, air conditioners, etc.). I do that to avoid the very type of problem that you are describing.
But I'm probably in the minority among those who focus seriously on power distribution. Most people put purely digital components on separate dedicated runs, to prevent cross-coupling of digital noise into analog signals. It's probably debatable as to whether a dac is a digital or an analog component. I would consider it to be analog, to prevent its outputs from being contaminated by noise from digital transports and other purely digital things.
Many people also put their power amps on separate dedicated runs, because of their large and fluctuating current requirements. But as you appear to have found, that creates the risk of ground offsets relative to the preamp.
I guess the bottom line is that some experimentation and trial and error tends to be necessary.
Regards,
-- Al