Marshall 1959/1987 and 2203/2204 mods

[roberto]

Hi everybody, I would like to collect here all the common (and not) mods that we have already done to 1959/1987 and 2203/2204 amps.

In my mind this thread should stay quite clear from noobies asking a fender clean together with a Marshall crunch and a Soldano Lead.

Let's start with the first one I posted yesterday on the other thread.
It's for 1987 and 1959 too, of course, and the MVPPI can be switched on/off to have two different volumes for rythm and solo.

[roberto]

Some #34 schematic and layout I dowloaded probably from metroamp years ago.

[roberto]

Same story for the #36.

[roberto]

Randy Roads mod

[roberto]

Dual PPIMV mod

[roberto]

This is one of the best and cheapest hot rodded Marshall ever built.

The only mod I suggest is to add 2k2 to the resistor going to the PI: this will lower all the voltages on the preamp to something around 250V, improving the whole response of all four channels.

[roberto]

Trainwrecked plexi

[roberto]

Rockstah's mod5

[Tone Lover]

Thank you Roberto. Theres alot of good stuff there nice to have it all in one place instead of like I have it.
Piles of paper with schematics and diagrams stacked all over the place. (LOL).
Bill

[roberto]

I have these and all the other mods in a specific directory, as for all the other schematics. But if it's a one way thread I will keep the others for better times.

[pdf64]

Please keep them coming, I'm grateful to have easy access.
So many of these mods are often just text descriptions of the changes to a stock model, which is a put off for me (too lazy to sketch them out).
My preferred mod to any 5F6A type tonestack is to change the mid control to be a variable resistor, ie link the hot track end and wiper terminals.
It greatly increases the range of the bass control, enabling a less bass heavy tonal balance.
Yet it retains all of the previous settings (just need to turn the bass up a fraction more than before).

[xtian]

+1, Pete, and I really like replacing the Mid pot-to-ground connection with another pot, to provide a variable tone stack lift.

[dorrisant]

Thanks for sharing, Roberto!

[dcribbs1412]

Thanks for sharing, Roberto!

+1
Thanks Roberto

D

[mmmoser]

I seem to have collected a few of these mods over the years as well.

Here's one called 1959/2203 switchable