Douglas
I had a similar incident with my tubed DAC a few years ago.The DAC was ARC DAC-3 and was bought used,it came with bad 6922 tubes.I first thought it was the pre-amp at fault because every time I touched the volume,cracling noise heard from the speakers.I actually sprayed the volume pot with Craig cleaner.Finally I realized it was the DAC and sent it away to ARC.They replaced the tubes and a few other things.
You don't give us enough information to work with.What was the problem?
George
