Op-Amp FUZZ ?

[JEPorter]

What would be a low parts count fuzz circuit that uses an op-amp?
The fuzzier the better:)
Jeffrey

[JEPorter]

I already thought about the Muff Fuzz and plan on trying out that one...

[anchovie]

Anderton Comparator Fuzz

http://www.diystompboxes.com/smfforum/index.php?topic=67377.0

[petemoore]

  One stage Tube Reamer, the next stage, Dist+.
  That'd be muff-like at least in the way of 2 clipping stages.
  Because opamp come in dual package, 1 package could do it.
  If tone control loads signal, something like more active stages to drive it..?
  interesting ?>an opamp deal with many 'light-boost-clip' stages after the 1rst stage [set for enough boost so that the diodes in it's stage or the second stage lightly clip signals.
  Anyway maybe boost sounds good w/TR, or D+, with separate switching or creative routing it's possible to get a Disto+Fuzz, of course experimenting with 'sustain' controls [beginning/between 2 stages]...you might find knobs afford suitable control.
  Boost and a couple distortion OA stages, some re-routing and knob twisting later [perhaps a few mods..] should be able to provide with Fuzz [let the treble through] and Distortion [cut treble or inputs gain].

[Paul Marossy]

I like the Black Cat OD-1 (AKA "Freddie Fuzz"). You can get a good range of sounds out of it and it's quite "touch sensitive".

http://www.diyguitarist.com/PDF_Files/BlackCat_OD-1.pdf

[brett]

Hi
Lowest parts and mild fuzz (can you even call it a fuzz?)= Tube Reamer
More parts and super fuzz = MFZ-1 or Hidrosis
If you can design stuff, you could do a dual opamp version of the Fuzzrite.  It's a crazy fuzz.
cheers

[Nasse]

Just when I thought using opamp in fuzzrite style circuit? I could not find opamp fuzzrite schem but did not search much

[John Lyons]

If you can design stuff, you could do a dual opamp version of the Fuzzrite.  It's a crazy fuzz.
cheers.

[glops]

A dual op-amp fuzzrite circuit !   I bet it sounds crazy, sounds really fun!

[Gila_Crisis]

an opamp big muff??

http://www.aronnelson.com/gallery/main.php/v/Gila_Crisis/Big_Muff/Opamp_Big_Muff/

[Mark Hammer]

The non-octave section of the MXR Blue Box provides a much better fuzz than I would have thought.  It does not use any diodes (at least ones external to the chip).  Building a Blue Box without the octave down (and accompanying circuitry) would make a decent (and well-behaved) fuzz. 

[fuzzo]

I've just made one , a la "freddie fuzz" , juste two AOP the first in the second . Two inverter gain stage (1M in the feedback loop) with a "grain" pot between both  AOP , big cap (1uf for out/input) and the sound is really fat and gainny , a little like a big muff can be (at least mine is really close to my big muff  ). I put LED w/ 1M to get a smoother sound.

For me , isn't really a "fuzz" , more a distortion I'm not really fan of that kind of sound, It had, also a huge output volume (crazy thing!) allowing any tonestack (even  big muff) .

  I prefer sound foxx tone or fuzz face , but I think with work on the filtering and gain we could make a good sounding pedal .

To have a start point look at the frantone peach fuzz, that basicaly that kind of circuit.

[Paul Marossy]

I've just made one , a la "freddie fuzz" , juste two AOP the first in the second . Two inverter gain stage (1M in the feedback loop) with a "grain" pot between both  AOP , big cap (1uf for out/input) and the sound is really fat and gainny , a little like a big muff can be (at least mine is really close to my big muff  ). I put LED w/ 1M to get a smoother sound.

For me , isn't really a "fuzz" , more a distortion I'm not really fan of that kind of sound, It had, also a huge output volume (crazy thing!) allowing any tonestack (even  big muff) .

Depends on how you set the controls. I also added a tone pot at the input and ouput, which really shapes the sound a lot. I find it is too fuzzy sounding for most of the tunes I play at church, but great for a "Face First" era Scott Henderson type of a sound. YMMV.

[JEPorter]

Thanks guys
Those are great ideas...
Jeffrey

[punkbass]

if you want a simple opamp fuzz with epic super distorted squarewave output, you could build the next thing:



                                                                                                                                   |----------------------------------------v    |
                                                                                                                                  V                                      _________|
     | v---------------------------------| +  \                                    |--------------------------WWW-----WWW---------------|
     |__________________        |       \_________________|                                                                         _|_
               _|_                    |         |       /                                                                                                              --
                --                     |--------| -   /


the opamp is powered + and - 1.5V. the pot is 100K (log)  and the resistor is 50k. a 741 is a good opamp for this thing, it will output  some nice chaos.
(sorry for the crappy ascii art)

[ashcat_lt]

No idea what that ASCII mess is supposed to be, but the actual words point to something I tried and liked quite a bit - lower rail voltage instead of clipping diodes.  I used an LM324 running at just above 3V with all four sections basically cascaded into one another.  If biased to half supply, you get assymetrical clipping very much like an LED/diode combo because it'll go all the way to ground, but not to the positive rail.  Filter between stages, and for actual fuzz, dump most of the treble before the first stage.

[punkbass]

sorry, its a opamp with the + connected to the signal and the - to the ground, and no feedback resistors. it will put everything above 0v to the 1.5V and under the 0v to the -1.5v, a full squarewave is outputed via a logarithmic pot.

[antonis]

Does a 741 operate at +- 1.5V..??

[punkbass]

the input i give it on the Vcc and Vee is +/-1.5v, it is able to handle up to 12v as max diffrence between the higest and lowest voltage i believe

[ashcat_lt]

The datasheet I looked at doesn't have a minimum operating voltage, but states absolutely maximum as +/- 22V.  It also doesn't seem to indicate directly how close to the rail it will swing in either direction, which is an important part of the equation.  If you've actually built it, and actually measured those voltages at the output, though, it pretty much answers the question.