almondcity
Well-known member
I've built a few with pots for those resistors and it's pretty cool. Makes a huge difference
Bassifying a Muff
- Thread starter BuddytheReow
- Start date
So far, here's what I like:
Still to try:
- Coupling caps at 180n. This feels a little bass heavy until you up C2, C5, C8 (madbean schematic) to 500pf. Then it sounds just right.
- That final resistor should be 2k7, NOT 2k (typical of most russian layouts). The 2K7 just gives the whole thing a lot more presence.
- Green LED's for 2nd stage clipping.
Still to try:
- Green LED's for the 1st stage clipping. I have them in another muff and it is a little more open sounding.
- Experiment with the limiting resistors. Currently 10K, but want to give 8K and 12K a shot.
Feral Feline
Well-known member
Sorry, just saw this.
No, that wiring will not work.
I've got too much on my plate until next week before I can take a crack at making a diagram.
My suggestion was more a "DIY and see for yourself" thing for you to experiment. I doubt it would make a difference whether the clipping-cap is before or after the clipping-diodes — but I've never experimented with this. Theoretically a bumble-bee shouldn't be able to fly. So, I think it's still worth trying on the breadboard or simply installing the order-switcher even if only temporarily to see for yourself/myself if there's a difference.
Your post #39 was excellent.
In the quoted post above, I'm not sure what you mean "430p for more Civil War".
I think it'd be worth posting the Madbean schematic in one of your posts, so it's easier to follow what you're saying when you reference it.
~~~~~~~~~~~~~~~
Further to keeping clarity for everyone I'm reposting the OP's schematic below:
And it was reposted in #18
Compare and cross-reference the OP's schematic with Kit Rae's schematic that lists what each component is/does:
Referencing what the component is instead of its # (which varies depending on the source) may hopefully regain some clarity?
So... as you note, the lower you go the more fuzzier, or "crunch/drive into each clipping section" as Kit Rae puts it.
The fuzzier/crunchier it gets, the more the highs will pop out/be prominent. This might be desirable if the overall circuit is quite bassy via enlarged coupling caps. I think your 12k idea will result in a smoother OD-like sound, especially if combined with bassy coupling-cap values (which according to Kit will "sacrifice crunch".
So if enlarging coupling caps, it may be worth while to lower the limiting resistors to restore some of the fuzz/crunch. At what point does it turn to mush?
No wonder this circuit is so popular to tweak.
Do you want a very typical biting circuit, as found with guitar-centric Muffs, retaining note definition; or
do you want a smoother creamier fuzz with plenty of lows that may sacrifice some definition.
It's a real balancing act and tastes/goals/objectives vary!
Here's the Madbean schematic: that's what I originally used, so that's why I keep referring back to it.
But yes, a total balancing act. How to have a full and rich bass sound, but also have the option on tap to dial in some thick fuzz that cuts through with the Sustain/Fuzz knob? I personally want more of a deep overdrive tone with mids because I feel that with the bass guitar, too much top end and fizz loses the fundamental. But it is a balance because you still want to sit well in the mix.
So, with the Kitrae "circuit guide":
1. coupling caps: Up to 180 for more bass pass through in the circuit
2. adjust low pass filters to taste. Generally, 470 is Russian/Green, 430 is Civil War, and 500 is a little bit all over the place, but on some Tall Font Russian schematics.
3. R4/Bias for output makes a big difference in overall "openness" of the sound. 2.7 is much better for that than 2
4. Limiting resistors control the amount of signal going into the clipping sections. Lower values for more signal going in.
But yes, a total balancing act. How to have a full and rich bass sound, but also have the option on tap to dial in some thick fuzz that cuts through with the Sustain/Fuzz knob? I personally want more of a deep overdrive tone with mids because I feel that with the bass guitar, too much top end and fizz loses the fundamental. But it is a balance because you still want to sit well in the mix.
So, with the Kitrae "circuit guide":
1. coupling caps: Up to 180 for more bass pass through in the circuit
2. adjust low pass filters to taste. Generally, 470 is Russian/Green, 430 is Civil War, and 500 is a little bit all over the place, but on some Tall Font Russian schematics.
3. R4/Bias for output makes a big difference in overall "openness" of the sound. 2.7 is much better for that than 2
4. Limiting resistors control the amount of signal going into the clipping sections. Lower values for more signal going in.
finebyfine
Well-known member
I've always had this issue with Muffs so I've been paying attention to this thread with great interest. I've built a dozen plus Muffs and I have yet to hear one that I enjoy the sound of on my bottom two strings. I expected the Boris EQD variant to solve some of this, seeing as they play so downtuned, but found it to be even worse on this front.
I spent some time playing with the muff circuit in LTSpice before realizing I have no idea what exactly the waveforms, frequency response or FFTs would look like to indicate the issues with the bass response that I dislike. As already discussed, the coupling caps play a huge role in the amount of bass that comes through - 220nF and the bass roll off is nearly negligible, but I also am not sure if that is a good thing as far as feeding it into the clipping circuits. One thing I did notice is that the FFT for sine waves in the bass frequency showed a lot more partial subharmonics than I've seen in other circuits, to the point that with some values and pot settings the fundamental is much less prominent of a peak than I would have guessed, or appear in simulations of other circuits that I like with bass and C# standard tuning.
Long way to say I didn't learn much just yet from simulations.
Does anyone have the build docs for Grind Custom's Muff variants? Their stuff IIRC is intended for doom/sludge
I spent some time playing with the muff circuit in LTSpice before realizing I have no idea what exactly the waveforms, frequency response or FFTs would look like to indicate the issues with the bass response that I dislike. As already discussed, the coupling caps play a huge role in the amount of bass that comes through - 220nF and the bass roll off is nearly negligible, but I also am not sure if that is a good thing as far as feeding it into the clipping circuits. One thing I did notice is that the FFT for sine waves in the bass frequency showed a lot more partial subharmonics than I've seen in other circuits, to the point that with some values and pot settings the fundamental is much less prominent of a peak than I would have guessed, or appear in simulations of other circuits that I like with bass and C# standard tuning.
Long way to say I didn't learn much just yet from simulations.
Does anyone have the build docs for Grind Custom's Muff variants? Their stuff IIRC is intended for doom/sludge
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I do find that most EQD designs cut out some of the low end. Not sure why they don't just make a bass specific design.
finebyfine
Well-known member
I found the build documents for Grind Custom's Ultrastoner - https://www.docdroid.net/KcnBk3s/ultrabuilddocfinal-pdf
The docs have a table of values for other Muff variants too. I still need to look up an audio demo to see if it's better tuned for what I want though.
I remember that one from back in the day and built it up at one point-- but back then I wasn't really sure what I was looking for, so it might have been perfect and I wouldn't have known any better.
Feral Feline
Well-known member
In addition to the Ultrastoner doc you found, I've got most all of Grind's build docs, but have yet to build any Grind Muffs.
Let me know if you want any of the others, such as the Ultra78.
Note that the clipping-diode caps for the UltraStoner are C6 1µ and C9 100n.
That flies in the face of being good for bass as per the Russian-Muffs' 47n.
Then there's the fact that in DOOM mode, C9 100n gets run in series with C17 1n = 0.99n so... effectively 1n. So the first clipping stage gets all its bass clipped but nothing clipped in the 2nd clipping stage.
So, I guess what I'm wondering is, whether the UltraStoner will be any better on bass — seems to me it's tuned for doomy guitars.
Socketed a few more things last night. Some I’ve done before, but not as systematically as this to round:
—LED’s in the first clipping stage: really opens up the sound (more than I remembered) and makes the SI clipping a lot more usable for bass.
—lowered the limiting resistors from 10k to 8.2K. Love this as well. Gives it a slightly grainier, fuzzier, more rams’y breakup.
—switched out the 500pf caps for 470pf for a little more top end.
—LED’s in the first clipping stage: really opens up the sound (more than I remembered) and makes the SI clipping a lot more usable for bass.
—lowered the limiting resistors from 10k to 8.2K. Love this as well. Gives it a slightly grainier, fuzzier, more rams’y breakup.
—switched out the 500pf caps for 470pf for a little more top end.
Feral Feline
Well-known member
I found some time this evening to map out the clipping-diodes & clipping-cap order-swapper:
If you like, I can draw up a schematic for the above, too.
You'll have a bunch of empty solder pads on the PCB, the only ones that matter are the first and the last.
Here's a Pickle that has both orders, but if you were to experiment with the switch above, you'd want to pick ONE clipping section and connect the switch in and out points where I've circled for the relevant section, of course.
eh là bas ma
Well-known member
Thank you so much !
That's some serious wiring, no wonder i couldn't find the solution...
I've a 4PDT toggleswitch, i'll try to do the order-switching connections at both locations at the same time, and report.
finebyfine
Well-known member
Definitely me
Feral Feline
Well-known member
+1 interested party...
Haven't abandoned this project... just still playing around with it. I want to give it some time and go back and forth with some values.
Also, someone just suggested over on talkbass putting a resistor between the clipping caps and the clipping diodes as a way to give more of a "blend" of clean sound. I think the resistor just lessens how much clean signal is clipped so that you ultimately have more clean coming out of the clipping stages. I hope to test that out tonight.
Also, someone just suggested over on talkbass putting a resistor between the clipping caps and the clipping diodes as a way to give more of a "blend" of clean sound. I think the resistor just lessens how much clean signal is clipped so that you ultimately have more clean coming out of the clipping stages. I hope to test that out tonight.
I'm finding that if I reduce the value of the clipping caps from 47n to 18n (what I had on hand), a lot more clean bass is passed through and only the top end gets clipped. This sounds good to me... but I have been looking at all of the popular schematics and nobody goes below 47n on the clipping caps. Is there a reason for this that I'm not seeing?
jimilee
Well-known member
You’ve invented a new pedal. Market it! I’d love to hear it.
I hope so!
