Modded Big Muff is too quiet!

[nbabmf]

Is there a simple way to increase the output of the circuit after putting germanium diodes in both clipping stages?  Unity used to be about noon on the volume pot, maybe a little lower... and now it's around 2 or 3 o'clock.  I like the way these diodes sound, so I don't want to take them out unless I have to.  I would like to be able to slam the front end of my amp with this pedal.

This site mentions changing the emitter resistors to increase how gainy the pedal sounds, but I'm thinking that's more along the lines of saturation and not output.
http://rkerkhof.ruhosting.nl/Taas/Mods/Big%20Muff.htm

Any ideas?

[compuwade]

Is there a simple way to increase the output of the circuit after putting germanium diodes in both clipping stages?  Unity used to be about noon on the volume pot, maybe a little lower... and now it's around 2 or 3 o'clock.  I like the way these diodes sound, so I don't want to take them out unless I have to.  I would like to be able to slam the front end of my amp with this pedal.

This site mentions changing the emitter resistors to increase how gainy the pedal sounds, but I'm thinking that's more along the lines of saturation and not output.
http://rkerkhof.ruhosting.nl/Taas/Mods/Big%20Muff.htm

Any ideas?

There might be a simpler way, but adding a fet booster between the circuit output and the volume pot is pretty easy. You just set the gain for the booster with a trimmer to bring it back up to where you want it and then use the volume pot as normal. I suggest breadboarding a few different boosters and try them after the big muff to see if you like it. 

[T1bbles]

Pulling out or bypassing the tone stack gives the big muff an unholy amount of extra volume, might wannt try that.

[John Lyons]

The last transistor is a boost to pump up
the level lost in the tons section.
So if you add a boost it would be two
boosts in a row, not the end of the world but...

How much do you like the tone controls?
As mentioned, bypassing the tone stack
will get you there for sure. You can add
in a low pass filter if you have too much
high end. You can do this on the board
pretty easily with the existing holes...
Try connecting a wire from the .1 after
Q3 and the other side to the base of Q4.
That will be a tone section bypass.

See what you think. It's a lot different
sounding but take a listen...

John

[compuwade]

The last transistor is a boost to pump up
the level lost in the tons section.
So if you add a boost it would be two
boosts in a row, not the end of the world but...

Very true...didn't think of that. However the tone bypass for me can make or break the circuit. It really depends on the amp you have it connected to. It sounds like crap with my Fender SS amp. But with my Valve Jr the tone bypass rocks!

[nbabmf]

Right now, I have a toggle switch on the side to take the diodes out of the feedback loop in the second transistor stage.  I thought about using that switch to bypass the tone stack instead, since that diode lift sound is far too farty now with the changes I made.

[nbabmf]

I used the toggle switch I had for lifting the first pair of diodes and instead wired to to bypass the tone controls.  Well, there's the volume I was looking for!  I like the sound a lot.  What I may do is put a couple more toggle switches on the side to change the diode pairs for silicon when I want a more traditional Muff sound with a bunch of volume.  Bypassing the tone made me realize how scooped the Muff is and how valuable that extra volume can be.

Options, options, options.

[John Lyons]

"I love it when a plan comes together"  -Hannibal (The A team)

[Caferacernoc]

You could also put a 25uf cap in parrallell with R23 to boost gain:


http://www.generalguitargadgets.com/pdf/ggg_bmp_tbp_sc.pdf

[petemoore]

  Use the Input/ staging caps to trim bass.
 Switch for this.
 Switch for the TC bypass, perhaps a treble bleed control [cap 'n pot to ground, not sure but perhaps a third switch could make the TC knob a treble knob, I'll take another look. Variable HF control is nice to have if you like to use the amp at different volumes or adjust the gain, switch for bass lift may come in handy too.
  What the heck...looks like you could just do a DPDT switch insert at points:
   R19 / C11
  the other side of the DPDT
  at c16 / c10
  The .01uf probably won't be enough variance [might not roll of much treble] alone though, but with 3PDT you could parallel a cap to make that value larger.