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Marshall Tone-tweak Question

2/16/1999 9:35 AM
Doc	Marshall Tone-tweak Question What's the recommended mod for reducing the excess treble response of the JCM 800? A friend of mine has a 50w Lead MK II. He plays it at reduced volume (maybe half) most of the time (in the house). Even with the Treble control turned all the way down, it's too bright with a LP guitar. I noticed it's worse in the high gain mode, but still bright in the low gain. I looked at a schematic (2203?). There's a bleed cap across 470k resistors in two stages, and a bright cap across the volume control. He likes the general sound of the amp (4x12 cabinet) and doesn't want that altered, but he'd like to reduce the excessive treble. What's the recommended fix to take care of this? Should a particular bleed cap be removed, or all three? Should the tone stack be altered for a more flexible treble control? Thanks for your help. Doc

2/16/1999 9:35 AM

Doc

Marshall Tone-tweak Question

What's the recommended mod for reducing the excess treble response of the JCM 800?

A friend of mine has a 50w Lead MK II. He plays it at reduced volume (maybe half) most of the time (in the house). Even with the Treble control turned all the way down, it's too bright with a LP guitar. I noticed it's worse in the high gain mode, but still bright in the low gain.

I looked at a schematic (2203?). There's a bleed cap across 470k resistors in two stages, and a bright cap across the volume control.

He likes the general sound of the amp (4x12 cabinet) and doesn't want that altered, but he'd like to reduce the excessive treble.

What's the recommended fix to take care of this? Should a particular bleed cap be removed, or all three? Should the tone stack be altered for a more flexible treble control?

Thanks for your help.
Doc

Replies:

Dave H He’s playing at home with the vol p... -- 2/16/1999 10:34 AM
SpeedRacer Turning up the volume would help a ... -- 2/16/1999 11:39 AM
Mike B Doc,I own the 50W (2204) ve... -- 2/16/1999 12:46 PM
Chip I've spent a lot of time working th... -- 2/17/1999 8:29 AM
TMiller Remove the second 470pf bleeder cap... -- 2/17/1999 10:15 AM