I have to wait for the opamp and the input transformer for ending the amp!
shipsupt, do you already compare the monolith with an other amp?
The household voltage in my place has been always on the high side.
Victim No.1 is one of the diode on the psu. After replacing both of them neither channel is working.
Hooked up with a oscilloscope every channel looks like this with 1k sine wave input.
Did I broken all the OPs?
Well, I have to share how I fixed it.
The amp is oscillating, it appears as output wave when turned on, but soon output straight dc keeps increasing until it's 13v(L- L+ R+ R-) to the ground.
As I trace the signal with osocpe probe I realize everytime the probe connect to anything along the signal path feeds into the opamp will zero the dc offset.
Considering the oscope probe as a 1m resistor to the ground I added 4 100k resistors to ground on each signal path before R6 R7 R13 R14. Problem solved.