kasperhauser
pfm Member
Perhaps not exactly "classic", but as it involves a classic-era preamp, I'll ask here.
I posted awhile back about my new/old preamp, made by the Quintessence group in the early 70s. It has developed a channel imbalance; left is down ~10 dB in very non-scientific testing. Happens on all inputs, and it's always there, not intermittent.
My question: is there a "usual" culprit when this happens? Should I look at the volume and/or balance pot, or is it more likely to be components in the circuit? I should note that the volume pot that's in there appears to be a replacement. It isn't as old or nearly as robust looking as the balance. Also, there's never been any hint of scratchiness that might indicate crud in any of the controls.
If it's likely to be pot-related, I can try cleaning or even replacing, but I'll seek professional help for anything beyond that, which will be difficult as there are no repair shops left in my town, so a 100-mile drive would be required.
Any advice is welcome.
I posted awhile back about my new/old preamp, made by the Quintessence group in the early 70s. It has developed a channel imbalance; left is down ~10 dB in very non-scientific testing. Happens on all inputs, and it's always there, not intermittent.
My question: is there a "usual" culprit when this happens? Should I look at the volume and/or balance pot, or is it more likely to be components in the circuit? I should note that the volume pot that's in there appears to be a replacement. It isn't as old or nearly as robust looking as the balance. Also, there's never been any hint of scratchiness that might indicate crud in any of the controls.
If it's likely to be pot-related, I can try cleaning or even replacing, but I'll seek professional help for anything beyond that, which will be difficult as there are no repair shops left in my town, so a 100-mile drive would be required.
Any advice is welcome.