sxty8goats
Super Member
I'm finally able to start focusing on my MC240 that I picked up a month or so back. I'm good with part for part swap and A-B wiring. The rest of it I need a bit of help with.
Progress so far:
Audiodon helped me a few weeks back. He tested the tubes and found all to be good with 2 of them being on the low side of good, the rest testing strong.
He brought it up on a variac and he found AC voltage but no DC voltage. The amp did not pass sound, with known source. Tubes glow.
My buddy at work took a look and he feels the caps in the power supply are shot, will bring a tester in tomorrow for the caps themselves. We have 115VAC at the plug. 155VAC at the transformer, measured on the red wires between Sr1 and Sr2 / between c23 and c24.
My buddy suspects the caps are gone but the transformer (T3) is good. Will know more tomorrow.
I plan on and have planned to from the start, replacing all the caps, testing the resistors to see if they are in spec and replacing any that are not. My concern is the transformers. There is no "I let the smoke out" smell in the amp.
Questions
From above, does our logic / findings seem sound?
Do I have enough info to be 90% or even 80% confident in the transformers?
I have searched but have not found a parts list / kit recommended on AK. I suspect there are likely threads with posts in them with that info but no specific thread has popped up. Can someone point me to a source of kits?
And finally, any recommendations?
Thanks everyone.
PJ
Progress so far:
Audiodon helped me a few weeks back. He tested the tubes and found all to be good with 2 of them being on the low side of good, the rest testing strong.
He brought it up on a variac and he found AC voltage but no DC voltage. The amp did not pass sound, with known source. Tubes glow.
My buddy at work took a look and he feels the caps in the power supply are shot, will bring a tester in tomorrow for the caps themselves. We have 115VAC at the plug. 155VAC at the transformer, measured on the red wires between Sr1 and Sr2 / between c23 and c24.
My buddy suspects the caps are gone but the transformer (T3) is good. Will know more tomorrow.
I plan on and have planned to from the start, replacing all the caps, testing the resistors to see if they are in spec and replacing any that are not. My concern is the transformers. There is no "I let the smoke out" smell in the amp.
Questions
From above, does our logic / findings seem sound?
Do I have enough info to be 90% or even 80% confident in the transformers?
I have searched but have not found a parts list / kit recommended on AK. I suspect there are likely threads with posts in them with that info but no specific thread has popped up. Can someone point me to a source of kits?
And finally, any recommendations?
Thanks everyone.
PJ