I was testing the output voltage on my amp today fearing a channel imbalance. Using the XLO test disk (Track 5 test tone) I get 5.30V in one channel and 5.15V in the other. Swapping the tubes in each channel (NAT Magnetic preamp) and BHK 250 didn’t really make much of a difference. Closest I could get them matched near that output level was .13V.
Is this difference significant? I have setups where I could match the channels closer than that. I’m not sure how audible it really is and how much is in my head.
Is there an adjustment for gain in the BHK 250?
I’m using PCC88 tubes in the 250 and just ordered a matched pair to see if that helps.