Solid State Guitar Amp Forum | DIY Guitar Amplifiers
Solid State Amplifiers => The Newcomer's Forum => Topic started by: Wicked_Tone on December 23, 2011, 01:40:15 PM
First of all, this is my first post and I would like to say 'Hello' to everyone on this site.
I have two Marshall Mosfet heads. One is is mint condition from 1989 and the other is from 1987 that appears to have had some replaced electrolytics and the input jack has also been replaced with a Switchcraft and this amp is going to be my test bed for mods and tweaks. I've cleaned the pots with contact cleaner and turned each pot many times to work in the cleaner, but the reverb knob is still scratchy and looks like it needs to be replaced. I want to replace all the pots with higher quality ones using flying leads instead of board mounted. Also what value/style pots would I be looking for and what website would be best to find them?
I found these pots:
http://angela.com/100kaudiotapersolidshaftguitaramppot.aspx
http://angela.com/250kaudiotapersolidshaftguitaramppot.aspx
You´ll have to get the same values, of course.
Don´t know whether you will have space for new, non-board-mounted ones though, because I guess the board is flush with the front panel.
Maybe you´d better leave it as-new.
Remember these were made in the early 80´s and gave long years of service, not bad at all.
Quote from: J M Fahey on December 23, 2011, 02:27:37 PM
You´ll have to get the same values, of course.
Don´t know whether you will have space for new, non-board-mounted ones though, because I guess the board is flush with the front panel.
Maybe you´d better leave it as-new.
Remember these were made in the early 80´s and gave long years of service, not bad at all.
Thanks for the reply. I haven't accessed the circuit board, but I agree with you. I'll stick with the same pots Marshall used. I'll just replace the reverb pot with the exact value and style. :)
If you post a few gut pictures, I guess nobody will get angry around here. ;)
I´m specially interested in the heatsink area.
Good luck and Merry Xmas.
The pot that won;t clean - remains scratchy after cleaning. Before you replace it, check and make sure there is no small DC voltage across it. ANy pot with DC across it will make noises if in the signal path.