JCM 800 Combo pots...


New Member
Sep 18, 2007
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Hey folks,

I'm a total noob here (first post)...seems like a really cool place. Anywho...

I have a 1982 Marshall JCM800 50 watt combo (model 4210, Ch. switching) that I acquired about 2 months ago. So far, I love the little bugger...I have just one problem: the "treble" and the "bass" pots absolutely do not work in the Boost channel. Turning them does absolutely nothing to my tone, yet I know they are hooked up because if I turn the treb, mid, and bass all the way to 0, then turn the treb or bass up just a little, I do get a sound (the Mid pot is the only one that actually shapes my tone here). Any ideas what the problem is? The pots aren't scratchy or anything. Do I need to replace them completely? Thanks for any help or advice!!! Also, any personal opinions of this specific combo is appreciated...I dunno anyone with this model. Thanks! :)