marshall 5212 pot values

[low light]

does anyone have schematics for marshall 5212 (fifty split channel reverb), i just need exact pot values?

i found one scheme but it is way too complicated and handwritten so it is hard to read anything at all.

thanks

[52 Bill]

does anyone have schematics for marshall 5212 (fifty split channel reverb), i just need exact pot values?

For which pots? All of them?

[low light]

well, yes, since i bought it used, and allmost all the pots have been replaced and few eventually died, I just wanted to be sure which pots to buy, to make amp close to it's original state.

[52 Bill]

Normal Volume: 22K Linear
Bass (2X's): 1Meg Log
Treble (2X's): 220K Linear
Boost Gain: 22K Linear
Mid: 22K Linear
Boost Volume: 100K Log
Master Volume: 22K Linear
Reverb: 22K Linear

[low light]

thanks,

But when I opened the amp, one of the few marshall pots still intact was A1M (1 meg) on master volume, so isn't it too big diference if replaced by 22k, or vice versa if someone replaced 22k with meg which worked fine? Wouldn't 1meg on a place of 22k allmost mute it?
Also, there is a presence control that held 4k7 marshall pot. does that value match?

[Enzo]

The master volume is just a voltage divider, so almost any value will work. The control is in parallel with a 100 ohm resistor, so I wouldn;t expect a ton of difference.

According to the schematic there is a 4.7k pot in between the master volume wiper and the FX send, which ought to act like a presence control. SO yes.

[low light]

thanks a lot,

just one more thing,
gain pot (on drive channel) affects the clean channel, it ads little hi-end drive when turned up. This amp can only switch channels by ext fs. When fs is not connected above problem occurs. It's like the fs jack itself is necessary for bypass to work fine.
Is there something I could do with it?

[Ferrari]

Foot switch needs to be in place otherwise both channels will be on.