ilovefuzz.com

... then I have a fun project for you! Joe Davisson's Shocktave is bad-ass. Here's the original schematic:
http://www.diystompboxes.com/analogalch ... cktave.gif

You can have fuzz only, octave mayhem, or variations in between. For me, the fuzz is kinda so-so by itself, so I'll be tweaking mine so that there is always a fair bit of octave no matter where the Mix control is set. And in the future, I want to incorporate a different fuzz front-end. And maybe somehow combine it with my WTF?! octave up fuzz. That would rule.

There are some cool synthy, Atari-ish glitch things going on during note decay. Sounds pretty cool. In the second section of the demo below, I do simple single notes with the pedal set to do the funky Atari stuff. Changing pickups and adjusting guitar volume and tone controls make fairly noticeable changes in behavior. It's interactive, ya'll!!!



Here's the dickin' around clip:
http://www.archive.org/details/ShocktaveFuzzDemo



Here it is sitting on my bench as I recorded:

neat. basically a transistorized blue box but with only one flip flop?

multi_s wrote:neat. basically a transistorized blue box but with only one flip flop?

I'm not sure. I've looked at it, and looked at it, and I just can't figure out how it works. If you have some insight, I'd appreciate you sharing it here:
http://circuitworkshop.com/forum/index.php?topic=887.0

On some level, I want to know how it works. But the kid in me (the frosted side of the shredded wheat) just likes that it works.

well it looks like the first stage is an emitter follower/think buffer. the next stage is common emitter more or less. Thats where your getting the gain. The criss crossed pair on the right is i think some sort of bistable latch configuraiton/flip flop. It will work as a frequency divider.

off the top of my head im not exactly sure what the middle transistor is doing. it will have somethign to do maybe with enabling/disabling the latch.

edit: actually the way the latch is set up i think it will just oscillate when its powered, which is effectively when the diode is forward biased. i will look at it again when its a bit earlier in the evening. (;

multi_s wrote:well it looks like the first stage is an emitter follower/think buffer. the next stage is common emitter more or less. Thats where your getting the gain.

*That* part I get.

But thanks for your insights.

i wish i understood the why behind it all, but i can follow a schematic heh. definitely plan on trying this out.

i would suggest looking at it on a scope but my guess is that on the base of the middle transistor you see a very pointy signal. IE very narrow pulse square wave. like

----|------|-----

only with the spikes alternating up and down.

A positive spike turns on the oscillator deal long enough for it to change states. A negative spike will do nothing i think. So the result is the oscillator changes state every high spike -> the frequency of the oscillators output is 1/2 the frequency of the input (in a perfect world). To me it seems though if the oscillator was on for too long you would get the same frequency out as the input. But maybe thats what gives it its character. THe blue box method is a bit more solid for getting octave downs i would say.

If you look at the astable multivibrator circuit here there is a description of how it works (see figure 1, look familiar? )

http://en.wikipedia.org/wiki/Multivibra ... or_circuit

I got a brief but informative answer from ~arph over at circuitworkshop. He said:

"A frequency to voltage converter (the transistor with the diode) feeds a transistor flip-flop. (the last two)"

All of that seems to go way over my head. It sounds nice, though.

Didn't someone make some production pedal that was basically this?

D3rP wrote:Didn't someone make some production pedal that was basically this?

Yep. The Granny Puker.

I think they did a little tweaking of the circuit, but it's 99% the same.

That name always cracks me up.

Dude are those PCBs fucking purple?

McSpunckle wrote:Dude are those PCBs fucking purple?

Yes.

PM me if you want the info.

culturejam wrote:And maybe somehow combine it with my WTF?! octave up fuzz. That would rule.

O yes--FTW +1 googleplex give or take a few wins.

How would you do that--take the two roughly complete-ish circuits and smash them together in series? Take selected parts of each and combine them in a glitch-fizz souffle? Run them in parallel? All of the above?


Let'er rip, MR. Jam. I've got the Redenbackers.

McSpunckle wrote:Dude are those PCBs fucking purple?

Puuuuurrrple.