ilovefuzz.com

I have in mind a fuzz project that I could use at the end of the chain (or in aux sends of my portastudio) that could really destroy the sound. (I play some noisy ambient/drone stuff)
I think about the Fairfield Unpleasant Surprise, some kind of a gated fuzz that reacts to the enveloppe from the input signal.
I also would like to integrate a low pass filter to it. I want a fat textured sound, something close to a velcro type fuzz with some guts to it.
An octaver may be added for low end flavor too
Do you guys have some ideas or circuits to begin with?

Woolly mammoth maybe?

Parallel Universe II.

All the fuzz, Velcro, sag, oscillation, and general tone mayhem you'll ever need. Also has a built in send/return loop, so you can run other effects through it (like a wah). Built mine 5 years ago, and has never left my board. Ever.

If it interests you, let me know, and I'll look through my files to see which layout I used. One caveat; if using any kinds of buffers in front of it, you'll need to add a pickup simulator to maintain the proper impedance that it likes to see for the oscillation to work. Like I said, if it peaks your fancy, let me know, and I'll redraw my vero to include the simulator.

Parasit Studio has a vero available, but minus the simulator on the front end; http://www.parasitstudio.se/vero-layouts/parallel-universe#comments

The simulator I used is this one;


The switch simply mimics the differences between single coil and humbucking pickup. The pot acts as a fine tune, and adds another dimension as well. The important thing is that it creates the proper impedance that the circuit likes to see for the oscillation to work right.

IMHO, highly under rated, and not talked about much, but a wickedly awesome circuit.

I say bullshit with the pickup simulator since the PU is buffered by a TL072 with 1k input impedance. whatever sound difference you got can be done with resistors and capacitors in a passive tone network. you just need calculate the frequency response of the LC network in the pickup simulator and approximate it with an equivalent RC filter network. if you want to increase the input impedance more than 1K you can change that resistor. what you have with the 25k pot might work fine as part of the rc filter consolidated with the opamp input resistor.

eatyourguitar wrote:I say bullshit with the pickup simulator since the PU is buffered by a TL072 with 1k input impedance. whatever sound difference you got can be done with resistors and capacitors in a passive tone network. you just need calculate the frequency response of the LC network in the pickup simulator and approximate it with an equivalent RC filter network. if you want to increase the input impedance more than 1K you can change that resistor. what you have with the 25k pot might work fine as part of the rc filter consolidated with the opamp input resistor.

Your probably right, but I'm only stating what I've tested and works. A pickup simulator works in all situations, is low parts count, and to date, has not failed to maintain the PU's oscillation characteristics in all chain positions.

Like I said before, any type of buffer in front of this pedal, anywhere in the chain, will kill the oscillation capability of the circuit. I'm no EE when it comes to this stuff, but I know what I know. Just imparting what I've tried, and what works. If you've got a better mouse trap, have at it lad. Let us know how you make out.

all inductors are low pass filters. you said the pickup simulator is cheap, small, and low parts count. again, I would disagree. it can be replaced by, at best, the 1 resistor and 1 capacitor you already have at the input of the buffer. at worst, you would need two resistors one capacitor. you would be eliminating the $0.60 bulky transformer and replacing it with a resistor. you would get the same exact results. there is no iron core saturation at these low low voltages. pickup simulators work great in fuzz pedals that actually need them. I would never tell someone on the internet to go and buy some expensive bulky hard to find part when I know full well they can learn a bit more about electronics and build a better pedal with in stock parts. I am not trying to disrespect you or your contributions. you have helped me a lot through the years. stay toasty my friends.

PS. I built a few of these PU's over the years. I tried many pedal combinations. this pedal is a piece of shit and thats why everyone gets different results. I was selling a PCB that was licensed from collin. I was emailing him tech questions as well. this is all old stuff. I wish it would die. the LM386 is a horrible horrible line level driver. thats why it sucks. LM386 is a power amplifier. collin was experimenting. something cool happened. now everyone thinks this pedal is something they want to own but its not. it will create massive EMI fields in the audio range even with a metal box even with a ground plane PCB if you fly the wires. good luck.

PSS perhaps that big coil of wire in your pickup simulator is actually coupling the oscillation through a magnetic field generated by the LM386!

I build a Devi Ever GZ with a swtchable chaos mode. The shit was insane!! The GZ is a slightly modified version of the Soda Meiser which can be found here....

http://www.diystompboxes.com/smfforum/i ... c=106493.0

Although you do get the same buffer issue if it's at the end of the chain. To be honest, you may have the same issue with a lot of fuzz pedals.

Not Klon?

eatyourguitar wrote: this is all old stuff. I wish it would die.

Alrighty then... consider it died.

You should spelunk around Moosapotamus' website and check out the Jawari, and other stuff there.

Also, check out Tim Escobedo's "Bronx Cheer", which you can find over at General Guitar Gadgets.