More gain from GGG Guv'nor clone

[Dave Simpson]

I need to try and squeeze a little more gain out of my GGG Guv'nor clone. Any suggestions on value changes to achieve this would be much appreciated.

Schematic: http://generalguitargadgets.com/pdf/ggg_mgv_sc.pdf?phpMyAdmin=78482479fd7e7fc3768044a841b3e85a

[Bill Mountain]

Do you want more output volume or more distortion?

[GibsonGM]

R6 (680k) controls the gain of the inverting opamp stage that feeds the clipping diodes.  Rf/Rin, Rin being the 10k. Gain of 68 now. 

You may try increasing it (could put a 1M pot in temporarily to dial in a higher value...) to hit the diodes harder...but for what the Guv'nor is, I don't know if you'll like the results!  Could just go all fuzz and wool on ya...

To my ear, it's at the edge of what it can do well, as-is.  Another gain stage w/diodes and additional tone shaping would be needed to go true shred - just my 2 cents.

[Dave Simpson]

More distortion was what I was aiming for.

I agree, upping the gain would probably change the overall sound of the pedal. I was thinking that might be the case. Thanks for the ideas, I'll give them a try and see if it is usable.

[Bill Mountain]

You could try lowering R2.  That helps set the max distortion as well.  You may need to change C3 and C4 to adjust bass response.  Or like previously mentioned you can hit it with a booster.

[drolo]

What Diodes are you using to clip? If you are using LEDs try with 1n4148 or similar diodes with smaller forward voltage. Or go even with 2 GE diodes, even lower. That will give you more distortion/compression but less overall volume. Still you will be over unity. Test some.

I tried the above, but indeed there is a limit to what you can increase in terms of gain before it gets mushy, upping the drive pot for example gets over the top very quickly. But you can put a resistor in series with it, so that you can dial in that bit of "more" when needed.

Of those "more gain" mods, the best in my opinion is to reduce R2, this increases the gain and reduces bass at the same time, tightening up the sound a bit.

If you really need a way more heavy distortion, you may need to go for another type of design, like BSIAB and relatives.

[GibsonGM]

Yeah; R2 sets your input impedance for that stage, so you could get some odd effects if you go too far, which Drolo was getting at.  Other than diodes, I'm not seeing too many options for making a Guv'nor "shred" without going too 'fuzzy' in the process.

Why not start from scratch, design your own?  ;o) 

[Buzz]

I use a GGG Guv'nor too, with a partscaster (strat). Didn't get the big crunch out of it until I installed a stratoblaster in the guitar.

Maybe try putting a boost of some kind before the Guv' in your pedal chain. Takes it to a new level.

[Dave Simpson]

Thanks for the replies. I'll give the R2 value change and maybe 500K pot as well. Definitely don't want the low end to get mushy though.