Little Big Muff Mod question: decreasing gain
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Posted: 07 March 2010 07:09 PM

So I have an EHX Little Big Muff, and I want to be able to take the Sustain knob down to a more usable range. I never turn it past maybe 9 o’clock because everything after that is too over the top. Would simply changing out the Sustain potentiometer to a different value effectively change the range? For instance, instead of having full blown shredding starting at 11 o’clock, I would want it closer to 3-4 o’clock, making the usable range wider. Ideas?

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Posted: 07 March 2010 07:15 PM | Link to this reply (#1)

There’s a resistor that goes from the outer lug of the Sustain pot to ground.  You can replace it with a larger value if you have the tools to do surface-mount.

Ron Neely II
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Posted: 07 March 2010 08:04 PM | Link to this reply (#2)

Try 10k-15k….. (limiting resistor)

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Posted: 10 March 2010 10:43 AM | Link to this reply (#3)

OK, so the 10k-15k suggestion is for the resistor that goes from the Sustain pot to ground, right? Thanks!

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Posted: 10 March 2010 06:01 PM | Link to this reply (#4)

Yes.

But decreasing sustain is just a matter of turning the knob down. The resistors not going to effect it on maximum setting at all because there’s zero resistance from lug 3 to 2 on maximum and there’s 100+k resistance to ground and the signal will take the path of least resistance…ie;lug 3 to lug 2.

If you want less sustain on a lower setting you would actually want to reduce the resistor as the lower it gets the more signal passes to ground and if you remove the resistor all together it will ground out and become silent, hence, basically become another volume pot.

I would put a 560 Ohm in it. Much less than this and you will have no distortion at all on zero.


(BTW, I misread your post the first time)


When a certain amount (I’m not sure of the actual percentage) of muff signal goes to ground it starts sounding bad as you would probably know from turning it down. IMO the muff sounds best with the sustain no less then 2 o’clock,it just doesn’t have a very usable sustain control. Its not actually a distortion control BTW,its just a pot between the first input stage which is a clean boost and the first clipping stage.

I’ve always wondered whether it would be better having the sustain pot pre- circuit rather than after stage one. A lot of fuzz pedals have this set up, I’ve never tried it on a muff but I have been meaning to.

The metal muff has a very usable distortion pot,it can be turned to zero and still sound really really good, its very user friendly.

Edited: 10 March 2010 06:14 PM by Liberty Belle
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Posted: 10 March 2010 09:17 PM | Link to this reply (#5)

I might get crapped on for saying this, but it won’t be the first (or last) time, so here goes nothing. To me, and with all that eye-straining SMT ‘stuff’, if you don’t like the pedal the way it is, flip it over and get a different pedal. Mucking about with the surface mount components, if you aren’t super careful and 101% sure of what you are doing, you risk ruining a good pedal. What if you want to put that itsy-bitsy-teeny-weenie resistor back? doh A vintage Little Big Muff is easier, but then again you are screwing with a vintage (and collectible) pedal. I don’t see a ‘win’ happening anywhere here, and just one lose-lose after another.

You can lead a horticulture, but you can’t make her think.“

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Posted: 11 March 2010 02:17 AM | Link to this reply (#6)

Vintage LBM’s and XO LBM are totally different! Still muffs, but not the same at all.

I do agree though ,unless you know what you are doing modding SMD is not a good idea. if however you do know what you are doing its no more of an inconvenience than modding any other pedal.

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Posted: 11 March 2010 02:49 AM | Link to this reply (#7)

here’s an easy way to do it without modding the pedal (which is a PAIN on SMD):

Give it less voltage:

http://www.beavisaudio.com/Projects/DBS/

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Posted: 12 March 2010 06:53 PM | Link to this reply (#8)

My fear is that less B+ doesn’t decrease gain, but headroom. The noise may come up as well, although for the life of me I have no idea why I think that.
Has anyone seen a real  schematic for this very pedal? Not a generic ‘Little Big Muff’ schematic, but the EHX with reference numbers for the parts? Maybe you can come up with some type of easy ‘snip, snip; less gain!‘ mod.

You can lead a horticulture, but you can’t make her think.“

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Posted: 12 March 2010 07:46 PM | Link to this reply (#9)

There’s a way to decrease gain easy enough but it still involves removing and replacing resistors.
Read my article here:http://sovtek.webs.com/bmpgainfactor.htm

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Posted: 27 April 2010 06:04 PM | Link to this reply (#10)
Liberty Belle - 12 March 2010 07:46 PM

There’s a way to decrease gain easy enough but it still involves removing and replacing resistors.
Read my article here:http://sovtek.webs.com/bmpgainfactor.htm

Wowie! Very in depth article, I think it all went way over my head. You really know your stuff. I have a few old pedals that I never use and I am thinking it might be fun to tinker with them. Good luck with your mod.

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