GarageFuzzz build notes

[PenPen]

Reporting on GarageFuzzz build. A few notes, this thing is LOUD. Very, VERY LOUD. The transistors I used are marked CDIL 2N2222A. Metal can. hFE ~200-230.

I got what I expected. This thing was exactly the way I imagined, and it even surprised me a bit too. It screams. No, literally, it screams, if you have the volume on your guitar all the way up, and as a note goes into decay, it just gives way to loud, screaming occillation. The freqency of this occillation appears to drop as you roll the knob back a bit, making for some cool noise sounds.

The distortion is, well, splattery, buzzy fuzz. Almost synth sounding. But the decay on this thing is abrupt, and if you have your guitar volume down, it just goes dead QUIET once the note decays. I'd say it quits after about 1-2 seconds after you pick a note. You would think this would be cause to write this off as a BAD distortion, but in fact it is made this way. Thats the design. And it is fantastic for noise. I could see someone like Sonic Youth using one of these.

I built it exactly to the schem. NO changes except I did leave out the resistor at the end, which is supposed to act as a volume cut. I built it w/o it due to other build reports saying it was really really quiet. I'm not sure why they had that response, this sucker is very very loud. Have I mentioned yet that it's loud?

A couple of changes that I found. You can omit the diodes completely for a less buzz and smoother distortion. Without them, I'd say this thing sounds similar to a Rat with the distortion maxed. With them its just over the top. The 10uF output cap is probably a bit high, it didn't change the tone at all when I removed it for a while. You could probably get away with a smaller value.

The one thing I'm going to try is changing the 2k2 bias resistor on the emitter of Q2. It may fix some of the gating sound and improve the decay. I just want to experiment and see what kinds of sounds I can get from this sucker. Also, I'm going to test a few other values for the caps. I also will try a 0.047 uF cap to ground to kill the AM radio this thing picks up. Finally, a 1M for anti-popping.

My only real complaint, and this is what is stopping me from boxing this sucker up, is that it puts a lot of noise on the ground, meaning it screeches even when bypassed. I don't know how this thing works, but I suspect its the collector to ground arrangement that is causing the insane bypass noise in this thing. The frequency of the occillation changes based on if the diodes are hooked up, how much of the signal the vol pot in the guitar is dumping to ground, etc etc. I really wish there was a way to make this thing less sensitive to what is being dumped to ground. That very fact will probably make it very unfriendly with other pedals in the chain.

All in all, this thing is definately worth at very least being breadboarded. If I can work out some of the 'bugs' that I found and make it less sensitive to ground, then I will definately be putting this to perf and boxing it up. Maybe send one to Sonic Youth as a gift or something

[PenPen]

Well, that was fun. Change the 2k2 resistor to 4k7, and the occillator goes nuts. You can still dial in the old buzzy gatey sound by rolling the tone knob all the way back, but I just had a lot of fun just 'playing' the occillator using the volume and tone knobs. This is a lot of fun on a Jaguar, since I have two circuits to play with.

With this bias point, this thing is now putting out Uglyface and SicBox sounds. This is fun, but strictly for noise purposes. This almost has me inspired to build an instrument around this circuit, to 'play' the occillator instead of messing with going through a guitar.

It did just occur to me that this circuit will vary wildly depending on the guitar that is run through it.


EDIT:

Changing 2k2 to 1k sucks. The output is mostly gone, but if you hit the strings hard enough it sputters loudly and crackles out. No good. Values below 2k2 don't sound good.

[jmusser]

You'll probably find out that a lot of your oscillations and screaming will go away, once you box it up and shield it from your amp.

[PenPen]

You'll probably find out that a lot of your oscillations and screaming will go away, once you box it up and shield it from your amp.

I'll try rigging up a quick and dirty shield with a peice of foil when I get off work to see if that eliminates the screaming. Though Doug did say that this this is sensitive to ground level. I'll try and see. I'm almost hoping it doesn't clear it up, actually, so it could double as a noise box. I was figuring I could disconnect the circuit ground in bypass with a 3PDT. I have some other things to try still with this circuit....

BTW, did you ever get this breadboarded? I saw your post on a previous thread that you were planning to, just wondering if you managed to get it running also.