Filters/tubes for Marshall Major?

  • Thread starter Thread starter dr teeth
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dr teeth

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I just picked up a model 1978 (bass) Major from 1970, my 2nd Marshall after just getting a 1959HW. The major could use a little better note clarity so I'm looking at the filters and JJ tubes as possible points to make improvements. I'm not against changing non-signal path e-caps either if it would help. Are there any coupling caps or other components that tend to fail in these beasts in general?

From schematics and threads it looks like it has a pair of 375uF and a pair of dual 150uF/200uF cans (paralleled for 350uF?) Does anyone know where to source these filters? I haven't pulled the chassis yet but will soon since schematics don't show voltage ratings, and I would go as high of a V rating as I can find in a quality cap.

The seller pics aren't clear but I see cement wire wounds I assume have replaced the 250 ohm hockey puck screen R's (and probably is 1K since that seems the standard 'mod' to ward off square wave signal damage to the OT). Does anyone run their Major on 470R screens and is that too much UL power "to be safe" for hard clipping?

JJ isn't my favorite power tube for 6L6GC even though they can take the plate V abuse of a Mesa coli. Is there any better choice to getting the new KT88 gold lions? It seems people are happy with the new version. And would the original Tung Sol 6550 not hold up in a Major way?
 
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