Quote from: Tassieviking on April 15, 2024, 02:49:34 PMHave a look at the last layout for the JC-120, it shows the layout of the same PCB I think.
The JC-120 appears to be 2 lots of JC-60 amps in one box.
This is the closest I have on that amp.

Perfect, thank you!
i'm going to check the values of the components and compare them to the ones on my jc-60 later to verrify that, but the layout seems identical.
Thank you a lot!

Have a look at the last layout for the JC-120, it shows the layout of the same PCB I think.
The JC-120 appears to be 2 lots of JC-60 amps in one box.
This is the closest I have on that amp.

ok i found an older service manual for the jc-60 #512400 (and higher) from june 1977.
it even includes a wiring diagram and a components layout for the jc-60 #481650-#502399, but it's still not the right version.
Does anyone have an idea where I can find the correct version?

Quote from: Jazz P Bass on April 15, 2024, 10:56:14 AMYour serial number indicates a manufacture date of June of 1975.
The schematics that you found are from 78 & 79.

Thank you for the info about the manufacture date! Seems to be the first version of the JC-60 then. I read somewhere that they started building the jc-120 and the jc-60 in 1975.

Your serial number indicates a manufacture date of June of 1975.
The schematics that you found are from 78 & 79.

Quote from: g1 on April 14, 2024, 02:44:32 PMThe service manuals usually go by serial number, what is it?

The serial number of the amp is #430830.
In the service manual is a note that for the JC-60 its for #787100- and for the JC-60A R&P its for #810530-. It was first printed on March 31. 1979 and its the fourth edition.
The amp is a earlier version, it has a different circuit board, different power transistors and has less control inputs on the back. i couldn't find the right service manual for my version. just the one mentioned and newer ones.
Does anyone maybe have an earlier service manual?

Quote from: saturated on April 14, 2024, 01:45:56 PMWow nice amp 

Welcome to the forum

 

Thank you!
 

The service manuals usually go by serial number, what is it?

Wow nice amp 

Welcome to the forum

 

added pictures