Quad Diode Array + Double Opamp Muff Fuzz fun.

[brad]

Hi again folks!  I used to be bobbletrox btw...

I was browsing through the Texas Instruments page the other day and found a cool lookin' chip - a Quad Schottky Diode Array, called the UC3611:
http://focus.ti.com/lit/ds/symlink/uc3611.pdf

I ordered some to try out and set about building a double opamp Muff Fuzz because I have the parts, and also because it would use 4 diodes.  In hindsight, I should have built a Bull Ant or somethin' but whatcha gonna do.

So anywho, I finished the oa double muff and crammed some 1n914s into the IC socket because the chips haven't arrived yet...and it doesn't sound that bad.  The noise is WAY LOUD when you're not playing- but it has some massive amounts of distortion when you do start playing.  May I also add that I just stuck two whole muff fuzzes together caveman-style on the same perf layout.  A PCB layout and the schematic are at the bottom of the page....

Oh yeah, the Diode Array.  I'm going to try one out when they arrive, so hopefully they'll sound good and be a novel way of placing clipping diodes in effects.  A mystery mojo chip!  Now if I can just get my hands on a dual transistor array, I'll be able to make a transistor Muff Fuzz that looks like it's made of ICs!  Or maybe a Blue Clipper with an array and a OPA134, the Burr Brown equilvatent of a TL701.

http://users.bigpond.net.au/styrowfoam/muffypcb.pcb

[WGTP]

Cool idea.  There are lots of nice variations available with different diode combos.

I really like the op amp Muff Fuzz, but lately have been switching the first op amp to a non-inverting Tube Screamer (Bull Ant) type set up for lower noise and more flexability with Tone Tweaking (like a Blues Breaker).

The higher the clipping threshold of your diodes, the less noise you will have.  Try LED's or an LED/SI combination or 4 SI's.  You may want to use all 4 diodes of your chip on each op amp.  You will get less distortion and compression, but that shouldn't be a problem with 2 in series.    :shock:

[black mariah]

I ordered some of those last week. Haven't got around to messing with them yet. One interesting thing would be the ability to switch in extra diodes without having to actually use... umm... extra diodes. Yeah, that made sense. *cough*

[brad]

The ICs arrived today.  Gone is the uber-saturated distort-o-beast and now the circuit is a pleasant tubey overdrive/fuzz with alot less noise.