Just finished building the Cornet2. Thanks Jim for the awesome piece of electronics. Everything works okay, but not perfect.
Unfortunately, the right channel is low, not by much, but noticeably lower to shift the balance to left side.
I swapped the 12AX7's and it doesn't solve the problem, but alters the levels making right channel worse off.
These are my voltage readings -
B+ - 366 (should be 365)
R211L - 338 and 311 (should be 330 and 300)
R211R - 339 and 314 (should be 330 and 300)
R219L - 175 (should be 155)
R219R - 193 (should be 155)
V200 Pin 1,6 Left - 185 and right - 203 (should be 150 each)
V201 Pin 1,6 Left 168 and right 185 (should be 150)
If I swap the tubes, the values become:
B+ - 364 (should be 365)
R211L - 337 and 310 (should be 330 and 300)
R211R - 338 and 313 (should be 330 and 300)
R219L - 190 (should be 155)
R219R - 209 (should be 155)
V200 Pin 1,6 Left - 168 and right - 187 (should be 150 each)
V201 Pin 1,6 Left 185 and right 203 (should be 150)
As you can see, Pin1,6 voltages also get swapped when changing the tube. Also the R219 voltage gets increased by 15 in both channels by swapping.
To me it seems like a tube problem, but I don't know jack about such complicated circuits.
There is also a hum/buzz (dont know the difference) in the sound. Both channels. Have properly grounded everything.