Mouthmeistor - Talking Filter Fuzz - First Design for the Forum

[Top Top]

This is a design sort of based on/expanded from two different Tim Escobedo designs - the Gargletron and the Ghost Dance.

I am a big fan of CMOS designs and all you can squeeze out of those little guys. I have never been fully satisfied with the sound of the gargletron but liked the concept...

This one is based on the 4069 CMOS inverter IC. Basically it is two wah type filters tuned to different frequencies swept by a pot in a blend-pot-style configuration to sweep them in an inverted way.

The transistor stage in the front provides a simple fuzz that does weird stuff with the filter. It never gets fully clean, but is pretty clean at minimum gain. At minimum gain it is about unity, maybe slightly higher.

You could rig it up in an expression pedal style or just use it fixed with widely variable tone settings. It makes for a cool psychedelic sounding fuzz as is. Just playing chords into it can give cool shifting harmonic sounds even without moving the sweep pot. The fuzz is definitely a "fuzz" and sounds pretty 60's... not an overdrive or distortion.

Sounds cool with synths as well...

With a pedal you can get wah and close to phaser sounds out of it, in addition to weird talking effects that don't quite sound like anything else.

I'm a noob, particularly when it comes to transistor and filter type stuff, so any suggestions welcome.

Resonance pots are optional, though they let you tune the amount of each filter.

I'll get some clips up soon with different settings.

[petemoore]

  Looks like dual filter fun !
 and cool, here's why:
  Simple implementation ! [for a dual filter design].
  Uses CMOS which can sound really nice. [not my favorite opamp because they actup, on me, perhaps I should order new ones.
   

[FUZZZZzzzz]

looks nice! when im done with my latest noise ill give it a try..

soundsamples yes!!!

[Slade]

soundsamples yes!!!

+1!!!

Looks very nice, Top Top, thank you!

[culturejam]

Looks like a good project to put in an empty wah shell. 

[Top Top]

Here's some sounds (four minutes of them).

http://www.youtube.com/watch?v=RIxTaWsEjrk

As you can hear, on the fuzziest settings, it still isn't all out fuzz fest... But enough to give the filter something to work with.

edit: I should also say that the resonance on both filters was up all the way all the way through, and if you want to eliminate the res pot, just put a 1M resistor to ground in it's place, or the filters might squeal.

And a pic of my latest attempt at an expression pedal rig:

[Fuzz Aldryn]

Wuhuuu! Sounds pretty nice! Now, how's about putting a good lfo to it? It seems to me that it could be possible to make a dirty phaser out of it (to be honest it is as dirty as my phase 90 clone is with humbuckers:D)

Cheers
Helge

[SpencerPedals]

Nice sounding weirdness!  Sounds like it would be also well-suited to be paired with some sort of crossover distortion.

[Top Top]

Wuhuuu! Sounds pretty nice! Now, how's about putting a good lfo to it? It seems to me that it could be possible to make a dirty phaser out of it (to be honest it is as dirty as my phase 90 clone is with humbuckers:D)

Cheers
Helge

There is a schem floating around to make a roughly triangle LFO out of three 4069 inverters. There are four left on the chip, but making it fit in the layout could be interesting. You would need to have an LFO and inverted LFO, with LDRs for each filter, so that they are swept inverted to eachother.

I think with a fourth inverter you actually could invert the LFO and do just that...

[culturejam]

Sounds like a promising start! Well done!

Definitely needs either an envelope follower or an LFO. Or maybe both on the Deluxe version.



If you want more fuzz, maybe replace that 2M2 collector/base resistor with a diode. Like a Bazz Fuss. 

But I do think it sounds cool as is. 

[Top Top]

Sounds like a promising start! Well done!

Definitely needs either an envelope follower or an LFO. Or maybe both on the Deluxe version.



If you want more fuzz, maybe replace that 2M2 collector/base resistor with a diode. Like a Bazz Fuss. 

But I do think it sounds cool as is. 

I've also seen an envelope follower made out of three 4069 inverter stages... never got it to work myself when I tried it on the breadboard, but I am pretty sure it was user (my) error.

[Top Top]

Sorry, don't know why I didn't think of this, but I also have a layout:

I've built it from this layout, so I guess you could consider it verified. I have only made a couple of layouts, so any suggestions are welcome there as well.



The LFO thing sounds like fun and I may get to trying it sometime, but not until I finish another project I am working on. However, if anyone feels compelled to give it a shot, here is the LFO I was speaking of:


more info: http://home1.gte.net/res0658s/fatman/4069_lfo.html

I've built that LFO before (for 12v with a few parts subs), but never attempted the inverted idea I mentioned with the fourth inverter stage.

[flintstoned]

Hey top top, in the sounclip were you using the expression pedal?

[DDD]

Great and simple re-design of the famous Anderton "Wah-Anti-Wah" circuit. Just with the same tiny mistake (inverter outputs shortage to ground in min\max settings of the SWEEP pot).
Very impressive attempt ! Regards !
Also, the suply current of the 4069 IC should be limited with serial 470 Ohm to 2 kOhm resistor, as usual. Otherwise 4069 consumes too much current.

[Top Top]

Sorry, I somehow missed these responses. Funny I just attended a jam/recording session for a friend today and made extensive use of this pedal.

Hey top top, in the sounclip were you using the expression pedal?

The answer is yes, I was.

Great and simple re-design of the famous Anderton "Wah-Anti-Wah" circuit. Just with the same tiny mistake (inverter outputs shortage to ground in min\max settings of the SWEEP pot).
Very impressive attempt ! Regards !
Also, the suply current of the 4069 IC should be limited with serial 470 Ohm to 2 kOhm resistor, as usual. Otherwise 4069 consumes too much current.

I'm not sure what you mean about the inverter being shorted to ground on the min/max settings. Why is that a problem? Shorting to ground is how the filter cutoff works.

As for the note about the resistor to limit current, it works as is, though I suppose someone could add that in if they build it to save battery life. Most pedals I personally run off of wallwarts, but in this build I did use a battery. I have used it a bit and still on the first battery I put in it.

[flintstoned]

Have you tried putting that lfo in there yet? Ive been meaning to try it out but haven't gotten around to it yet.

[Top Top]

Have you tried putting that lfo in there yet? Ive been meaning to try it out but haven't gotten around to it yet.

I actually have an LFO version that worked well on the breadboard, but I am having issues with getting to work properly on perf, so still trying to sort out exactly what needs to be changed about it. It is a one chip project though, if I ever get it to fully work!

The LFO/Inverse LFO I got to work, but just doesn't seem to be giving a good enough amount of sweep for the higher tuned of the two filters.  I am sort of stumped about it, might need to get an LDR that goes lower Ω in light than the ones I have.

[GodSaveMetal]

Top Top you have some more picture of your pedal I don`t see the details?? thanks a lot; very special pedal!!!!

[Top Top]

Top Top you have some more picture of your pedal I don`t see the details?? thanks a lot; very special pedal!!!!

What are you looking for exactly 

[GodSaveMetal]

Top Top you have some more picture of your pedal I don`t see the details?? thanks a lot; very special pedal!!!!

What are you looking for exactly 

Your pedal rig;excuse for my bad English please the detail of your pedal, can you???