Project overview
Inspired on Electro Harmonix Polyphase. Ready to challenge yourself with a rare vintage unit?
Introduction
Welcome to the experimental guitarist’s paradise. The Poly-face offers a level of interactivity way beyond a typical pedal to give you the most important thing: total control.
Its complexity enables you to have a level manage over the effects parameters that are not that far away from what a synthesizer can offer.
Not only does it deliver the classic phase sounds, but it also reaches new dimensions with its envelope filter mode. It is no beginner project for sure; controls for rate, feedback, envelope sensitivity, envelope modulation, and modulation rate plus a sweep toggle will do everything between funky envelope filter to Leslie-like rotary sounds.
Is it necessary to mention the enormous potential that this pedal hides behind these features?
Now let us go to the technical part; make sure you source your TL1054 from a trusted source. Also, keep in mind there are three optocouplers. If you decide to use LDRs and LEDs, you need to cover them (some guys put them in a heat sink tube) because otherwise, the light of one will affect multiple light-sensitive resistors at once.
Controls
- Mod
- Rate
- Sense
- Feedback
- Rate
For any technical questions regarding this build don’t forget to check out our Facebook Group and our forum at Free Stomp Boxes.
pink jimi (verified owner) –
four stars cuz of one caveat… it appears to me on my build this thing DOES need the thermistors. what i’ve found after a couple days of messing with it that after a time, when running, it the lfo stops. this appears to be temperature dependent around the rate pot and q1 in particular. haven’t yet had the time to replace q1 yet, but if i heat it up with my iron, the phaser works correctly. if i grab it with some needle nose pliers as a heat sink, it almost immediately will stop cycling again. its possible the one 2n5088 i installed in there is junk, absolutely. (tayda) but all the rest seem fine. i will come back and amend this once i get a chance to replace that transistor and see if the phenomenon repeats. the rate pot and envelope/sweep switch have been replaced with no change in behaviour.
this thing will be working fantastically, then suddenly stop running at the bottom of the sweep.. the lfo “hangs”.
if your build does this, or only seems to work with rate full down to about 2:00, then stalls, this is one of the hallmarks of the problem.
that said, i own one of the originals, and it was used in part for the diy project info to build these. the original manifests exactly these same behaviors which led me to think something is majorly wrong with it 😉 physically moving the env/sweep switch can usually cause hysterisis again and get the lfo moving. annoying, cuz i REALLY wanna use this thing.
other than the thermistors which i am suspecting to be the fix for my problem, this is a fun, satisfying build that sounds outrageous.
the regular phaser part sounds great, and you can dial up the feedback to the point it almost sounds more like a flanger. it sweeps deep and slow, with great harmonics.
the envelope part is a gas. it works as it should, little touchy to dial in, but sounds great and does some amazing gargly phase sounds. very touch sensitive. sounds great in front of distortions, too.
made my own vactrols, used flat square red ones with two ldr’s per led, with both sharing a center leg as the center tap. wrapped in black tape that i melted a little bit with my lighter. worked out great.
will report back when i find the fix. thanks guys, this has a lot of parts to go wrong, but it fired right up the first time i powered up. really nice layout, too. obviously done by someone with a brain and an understanding of how to do this right. i hate flying leads all over.
anyways… stay tuned
peace
Adam (verified owner) –
Wonderful layout of a fantastic effect. I used CLM8200/2 in mine and it sounds incredible. The coolest envelope effect out there.