Please could someone offer some advice? I'm building the m15mk1 and had come across some problems;
I completed all the wiring and triple checked everything. Voltages are all fine as per the schematic +/- 5%.
However, when I plug a guitar in, I get a horrible distorted gated sound (with a low level hum in the background).
Ive don't some tests and discovered that if I remove one of the power valves, is sounds like it should! So I think both powers tubes are ok as it works with either of them on their own. But with both together, its gated and horrible.
Any suggestions anyone? All the wiring seems ok, so I'm thinking maybe its the output transformer?
Can anyone help????
regards
Ryan