Green Muff Gruntbox

[bigmufffuzzwizz]

Here's a video demo of a Gruntbox built to Green Muff specs. I built it stock, no modifications. It's pretty wild and insane definitely sounds much different than Violet Rams heads I've built. I didn't worry about lighting since the box is plain and not to visually stimulating. Not to mention Youtube makes it darker and really destroys the sound quality. The gruntbox schem matches the current mudbunny so it could qualify for a mudbunny green muff as well!  

[TheCobbenator]

Sounds hot! I built a Green Russian Muff for my bassist this week and it sounds incredible with bass and guitar. Going to eventually do a little tweaking to make the mids control more useable, though.

[night-B]

Nice demo! Can't wait to finish mine 

[bigmufffuzzwizz]

Sounds hot! I built a Green Russian Muff for my bassist this week and it sounds incredible with bass and guitar. Going to eventually do a little tweaking to make the mids control more useable, though.

I've tried the mids knob on one of these and it doesn't seem to affect the sound or its very subtle. I used a 250Kb pot (lug 3+2 connected) with a 27k resistor across lugs 1 and 3. It measured about 25k on one rotation of the pot so i figured thats good. the other side measured zero. i'm thinking i need to play with the R18 value. were your results similiar?

Nice demo! Can't wait to finish mine 

i can't wait to do a triangle now!!!

[jtn191]

very nice video, man!--looking forward to hearing your triangle as compared to this. I'm gonna build a BMP to replace my LBM which sounds thin and "not gritty enough" to me

[TheCobbenator]

bigmufffuzzwizz --> Yes. I used a 25k pot and ...22k resistor at 18.   As it stands, right now, an untrained ear would assume I hadn't hooked up the pot at all.

I read in another post that cjkbug said: "i used a b20k pot and subbed in a 12k resistor at r 18. much more sweep."

...so I'm intrigued as to what socketing r18 and trying different resistors may yield. I'll post back whenever I get around to that... someday!

-Justin

[bigmufffuzzwizz]

The one I'm modifying is acutally a Violet Rams Head so my R18 is 39K. I did see that post by cjkbug and haven't gotten to try it yet. One thing I've noticed is that if R18 is lifted from the circuit the volume increased by a good jump. This happened on accident since the resistor leads are small that one keep slipping out of its socket. I noticed it was hanging but the pedal still working. The tone knob still worked sweeping from treble to bass but I'm guessing its not an active tone filter anymore. Before I solder a 12K to the mids knob wire, I'm gonna try attaching the mids knob with no resistor and see if I like it.

I socketed this board like crazy so experimentation would be easy. I haven't had much time to look at it and fool around but I have a list of about 7 big muff mods I'm gonna attempt. All of them are extremely easy and mostly just changing a component value. So far I've put jumper wires in the place of the first three transistors emitter resistors. It increased the gain much to my liking. The others are intriguing me now...

Edit:
If you haven't already checked out the big muff mods site easily findable via google, go do it! Each time I read it I seem to pick something else up from that site. This may be the solution to our problems..

Mid control mod: This mod is beloved by both guitar players as by bassplayers to regain the mids in the sound, mids that are so needed to be heard in the mix. With the next control you can dial in anything from a (huge) mid cut to a mid boost. Note that by boosting the mids you'll lose the Muff's character; still, it is a very nice addition!

•Replace C1 with a 22n cap
•Replace R2 with a 22k to 25k pot (wired as a variable resistor) with a 1k resistor wired in series.
This mod was designed by Jack Orman from AMZFX / Muzique.com. Great site with a lot of information!

My C10 (C1 in his diagram) is still at 4n which is the common value for most muffs with the exception of the op-amp versions. I'll give that a try today. I did fool around with it a bit last night. I tryed switching wires for the tone stack so I'd have the pot first then the 39K to GND. I was able to hear more of a change turning the pot but its still very subtle..gimme a sec  

[bigmufffuzzwizz]

I got it working! It sounds very good, and it really turned the muff into even more of an enjoyable pedal to me. This will be more than likely become a regular modification to most muffs i build. I followed the Jack Orman's suggestions on his site and now its a very functional knob. Changed R18 from 39k -> 3.3k and that was all it needed. I do have a 22nf in C10 so I'm gonna swap it out for a 10nf and try the regular 4nf to see which I like. I highly recommend the addition of the mids knob. I can go from almost no mids to what is definitely a mids boost. No change to the sound when the tone knob is on the bass side but in the middle-treble spectrum there is huge change! Video and pictures soon!