Bass Big Muff gutshots

[megadan]

Big fan of this pedal.

Most surface mounts components, obviously, but they are nice enough to label pretty much everything in there
Also true bypass as you can see.

[bumblebee]

Thanks for sharing, I've been wanting some shots of this one for my collection.

[panterica]

Wow. I was hoping to find the schematic for this and build it, but that's a lot of components. Looks like a lot of room for error for a noob like me..

[Russjp1985]

This post inspired me to take a look "under the hood" of my girlfriend's Bass Big Muff and see what's going on with it, since I had recently built 2 GGG BMP's to Green Russian specs.  The signal is split off right from the input, manipulated, and fedback at the very end (looks like this is bass boost / dry modes).  Ignoring that portion of the circuit (ie, having the Bass Big Muff in "normal" mode), it really is just the Green Russian Muff with a few slight changes.

I'm basing these component numbers off of this Green Russian Muff schem: http://www.generalguitargadgets.com/pdf/ggg_bmp_grus_sc.pdf
Comparing it to the GGG schematic of the Green Russian Muff, following the input directly to the 2nd lug of the volume knob (which would normally be the output), the only components that are differed are:

C1: ??
C10: ??
C14: 220uF
R19: 11.5K
R23: 2.7k
R26: 2.2M
Q1-4: BC547C

The change to R23 is actually the value used in the Black Russian Muff.   The major changes seem to be around the input (C1 / R26) and the tone stack (C10 / R19).  Unfortunately the input cap is located under the board so I can't get a good look at it.  C10 is not beneath the board, but it is not labeled.  For either of these, I don't have the equipment the equipment to measure the components, so I'm just be guessing, but I think its a fairly safe assumption that C1 has been raised to let more bass into the circuit.  Playing around with the Duncan Tone Stack calculator and the modded value for R19, I would guess that C10 has been raised also (maybe 0.008uF?) to flatten out the response or maybe even give it a slight mid hump. 

I am going to make some of these mods to one of my Green Muff clones and mess with the values until I get something I like.  Panterica: you might want to consider the same if you are interested in building a Bass Big Muff.  Add a switchable clean blend and maybe a diode lift on the first pair of clipping diodes, and you would probably have a pretty reasonable facsimile (or at the least, a functional equivalent).  Hope some of this was helpful :-)

[Projectile]

Thanks for the info.

[panterica]

This post inspired me to take a look "under the hood" of my girlfriend's Bass Big Muff and see what's going on with it, since I had recently built 2 GGG BMP's to Green Russian specs.  The signal is split off right from the input, manipulated, and fedback at the very end (looks like this is bass boost / dry modes).  Ignoring that portion of the circuit (ie, having the Bass Big Muff in "normal" mode), it really is just the Green Russian Muff with a few slight changes.

I'm basing these component numbers off of this Green Russian Muff schem: http://www.generalguitargadgets.com/pdf/ggg_bmp_grus_sc.pdf
Comparing it to the GGG schematic of the Green Russian Muff, following the input directly to the 2nd lug of the volume knob (which would normally be the output), the only components that are differed are:

C1: ??
C10: ??
C14: 220uF
R19: 11.5K
R23: 2.7k
R26: 2.2M
Q1-4: BC547C

The change to R23 is actually the value used in the Black Russian Muff.   The major changes seem to be around the input (C1 / R26) and the tone stack (C10 / R19).  Unfortunately the input cap is located under the board so I can't get a good look at it.  C10 is not beneath the board, but it is not labeled.  For either of these, I don't have the equipment the equipment to measure the components, so I'm just be guessing, but I think its a fairly safe assumption that C1 has been raised to let more bass into the circuit.  Playing around with the Duncan Tone Stack calculator and the modded value for R19, I would guess that C10 has been raised also (maybe 0.008uF?) to flatten out the response or maybe even give it a slight mid hump. 

I am going to make some of these mods to one of my Green Muff clones and mess with the values until I get something I like.  Panterica: you might want to consider the same if you are interested in building a Bass Big Muff.  Add a switchable clean blend and maybe a diode lift on the first pair of clipping diodes, and you would probably have a pretty reasonable facsimile (or at the least, a functional equivalent).  Hope some of this was helpful :-)

Thanks, man. That's really helpful.