It may be the famous ARC "blown resister". I traded in my ARC Classic 60 (for a VT-100) and the proprietor informed me that I had a "blown resister" on one of the tubes
(I had no idea there was a problem).
Now when there are 3 good tubes, the volume drop may not stand out (on a given channel). But in a power supply role, it may make a big difference.
Also, have you switched IC's lately? Going from RCA to XLR?
If so, there will be a drop in volume (at your regular volume setting).
(I had no idea there was a problem).
Now when there are 3 good tubes, the volume drop may not stand out (on a given channel). But in a power supply role, it may make a big difference.
Also, have you switched IC's lately? Going from RCA to XLR?
If so, there will be a drop in volume (at your regular volume setting).