ilovefuzz.com

Thought you guys might get a kick out of this one.

I always liked the original ROG Phozer's base sound, but the LFO wasn't really that useful at lower speeds. So I took the basic idea, which is the Idiot Wah + LFO, and kicked it up a notch. Instead of the Phozer's input JFET buffer, I went with an op amp buffer, and since there's an extra amp in the package, I also added an output buffer. The LFO is the same one I've been tacking on to everything the past couple years (from the STM). For the variable resistor element, I went with the H11F1 opto IC. But a vactrol or LED/LDR would also work very similarly (and actually they sound better).

It's not a phaser. It's not a vibe. It's not a tremolo. I suppose it's most like a phaser with a dash of trem, but it's really not all that much like any commercially available modulation. Which is probably a good thing.

This was something I drew up and hoped worked when I ordered the proto board. And it does work quite well. Surely there are many mods and tweaks to be made to improve, extend, or expand the tones available. I offer this working, fun, useful circuit to the community to experiment with and renovate.

Sound clip of the circuit with the H11F1 opto is below. I recommend going with a vactrol or LED/LDR pair instead. The sound is more intense and with a wider sweep.

[soundcloud]http://soundcloud.com/effdub/wahscillator-quick-demo[/soundcloud]


Populated board (some parts are surface-mount to save space).




And here's the schematic if anybody wants to play around with the circuit:

Cool circuit. Be nice to hear it with the LDR/LED combo

Gigahearts_FX wrote:Cool circuit. Be nice to hear it with the LDR/LED combo

It's similar, just more "depth" and a wider tonal change across the LFO sweep.

But I will be doing another demo with the LED/LDR.

That sounds pretty nice & interesting, culturejam.

I'd bet it sounds great with fuzz too.

Damn, I am glad I get to witness your brain power on a regular basis. That's fun.

Cool idea. if one used the opamp wah stage from deadastronaut's (or Morleys?) Lightwah, it would only require two dual opamps: Might try this afternoon. Thanks for the schem!

I love the sound towards the end with the rate up higher

Awesome! I was wanting to try something like this already, so the timing is nice.

Here's the sound with LED/LDR:

[soundcloud]http://soundcloud.com/effdub/wahscillator-with-ldr-led[/soundcloud]

Definitely sounds more like a wah and now nothing like a phaser.

Yeah, sounds more like a wah. Still sounds pretty nice though.

Sounds so great! Congratulations on the design, I really dig it, by the way, could you please tell me about the led and ldr you used instead of the h11f1? I am thinking about subbing this HF in other designs for a homemade "vactrol" and Id like to make a design a stripboard for the wahscillator too.
Thank you!

I used a cheap LDR from Tayda and a regular old 5mm red diffused LED.

hey culturejam, thanks for the post. neither vibe or phase, with added psychedelic sickbag. interesting.
looks a bit like the beavis' optochopto?



maybe it would be nice to vary this so it stuttered and wah'd.
or the caps tweaked so instead of wah-ing low to high freq the wah pot was replaced with a mid-scoop trim-pot, so the centre was sucked out of the tone and then pushed back in. that would be nice and weird. that would be the anti-wah.

It's theoretically similar to the OptoChopto, being a wah with an LFO to vary the sweep. But it's implemented quite differently (different LFO, different wah). The Chopto's LFO is one I tried many years ago. Can't get that thing not to make a ton of noise (not the good kind). It clicks like mad.

Adding a square-wave (stutter) is trivial. But it's not going to be all that square because the optical element doesn't react linearly (it turns on faster than it turns off).

This is so rad

You're cool with people building these up, culturejam? I'd really love to make my own.. I'm a fan of all things wobbly.