Marshall GV-2 Guv'nor Plus (EQ Mod?)

[jimosity]

I've got a Marshall GV-2 Plus that I would like to get a little more highs out of...anybody have any details of what to change to get more range out of the EQ section?

[kurtlives]

I would suggest playing with Duncan's Tone Stack Calculator.

You could try reducing the cap in the first op-amp's feedback loop. It would be fairly subtle but it might be right for you.

[jimosity]

Seems that simply clipping out C22 gives me exactly what I was looking for.
More usable post-gain treble gain.
That sure was easy.
No parts to replace or anything.

[Viks021]

Hi there,
although this was posted a while ago I just wanted to share recent experience, since I have spend an hour trying to find some mod for GV-2 other than just removing C22.

Although removing C22 is common mod for this pedal, I think that it leaves to much highs, especially if you use the pedal for live gig. I have experimented with protoboard and different C22 values, and also with different clipping sections. Here are my findings, that made this pedal WAY above the stock unit:
- replace C22 (original value on my unit 520 pF) with 150pF ceramic. Actually when I have measured mine it had around 170pF, and it makes a difference. Why ceramic - it bleedes high tones to the ground. For the same reason why you don't want to use it for treble bleed within the signal path, now I want that unwanted freq. grounded
- replace input capactitor C13 (orig. value 10nF) with metal film 22nF
- replace the rest of the capacitors on the signal path with the metal film capacitors (C11, C14, C2, C3, C4, C5, C1, C16, C17)
- added one more LED in series with one of the LEDs in clipping section to get asymetric clipping. I have tried several different types including Si and Ge, 3mm and 5mm LED of different collors, symetric or asymetric, etc. Finished up with 3mm red LEDs.

Having all tone controls alligned at 12 o'clock (maybe bass at 1) this pedal have serious tone. With gain at 12h you get AC/DC type of sound. With higher gain settings, when LEDs start to clip, you get thick modern dist, without JCM900 characteristic fizz or similar. Just a great and present sound.

I hope some of you will find this usefull and enjoy in rebirth of his GV-2 like I did.

Cheers,

Viks