My 2cents the Carver amp has a different way in which the input ground is connected to the case, attenuating thus the ground loop. Some amps use a resistor, e.g.
I do not think it would work - the signal/noise ratio will stay the same.
I would try breaking the return wire (shield) with a 100ohm resistor like at Avoiding Ground Loop Hum
Since your PC and pre-amp were connected to the same powerbar (which does have the ground line), you still had the ground loop closed.
The Dynaco's were designed in the 50's
Likely the security rules were a bit lower those days...?
Do the outlets have their ground pins connected with a wire in the wall/distribution box? I think they do...
You PC <--> pre-amp line is running at 8mV peak voltage? No wonder a ground loop makes it noisy...
BTW how about the output antialiasing filter of your soundcard which is a key part of the DA conversion? You are running the sample-hold steps from the DAC chip into your preamp? Maybe the tube amp provides the lowpass filter... But that is a different topic
No ground loop noise in my systemYou PC <--> pre-amp line is running at 8mV peak voltage? No wonder a ground loop makes it noisy...
BTW how about the output antialiasing filter of your soundcard which is a key part of the DA conversion? You are running the sample-hold steps from the DAC chip into your preamp? Maybe the tube amp provides the lowpass filter... But that is a different topic
With 2 ohm I/V resistor >8mV peak signal -when chips build in volume control is full open- there is no noise on my 94db speakers. I had to do a lot about ground loops to achieve this. With 56 ohm resistors > 220mV signal on the same preamp there is severe noise but still nothing to do with ground loop. I' not an expert on digital but I think the antialiazing filter is also build in the chip. A low pass analogue filter is expected at the tubes input I suppose, but also the tube stage is differential so it should act similarly to the opamp stage for this chip. Again I may understand it all wrong but one thing is sure, there is no noise in my system.
I'm open to whatever theories or suggestions anyone has...
Ground loop issue is an obvious problem.
I like the idea of a resistor to ground, especially if I can also reduce line output slightly...its pretty hot out of the Xonar!What I'm trying to do is to point another possible cause of your problem
What I'm trying to do is to point another possible cause of your problem
Since the noise is not present when using his non-earhed monoblocs, I assume it is caused by the ground loop. Plus I have multiple experience of the same problem, always solved by removing the loop by various means. The soundcards themselves are usually pretty clean, even onboard ones.
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