03-11-2022, 01:18 PM
I did a full power up, slowly bringing it up on the variac and monitoring things. Initially I didn't make it over about 65v when I noted my 1st problem. I have a really nasty oscillation. I traced it to the feedback loop. Temporarally disconnected and the oscillation ceased, continued power on up to 120v. I note a low 60 cycle hum and "solid state" like hiss when the volume it turned up. I double checked things but so far haven't found anything amiss. So, I have some checks to make and try to find out what is wrong. 
Being tho it's a 60cycle hum, it's likely filament related. This amp uses a pentode preamp so it's gonna be more sensitive.
Being tho it's a 60cycle hum, it's likely filament related. This amp uses a pentode preamp so it's gonna be more sensitive.
If I could find the place called "Somewhere", I could find "Anything"
Tim
Jesus cried out and said, "Whoever believes in me , believes not in me but in him who sent me" John 12:44
