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Question: is there a (relatively) simple way to reverse the envelope response and/or invert the LFO CV in single supply designs?

I think it would be cool to have a stereo effect(s) where the inverse response is happening in L and R channels, synced from the same LFO/Env.

ahhh, I found my problem... 82nF at C14 instead of 820pf. A bit murky

I'm working on trouble shooting my build but after reading this perhaps there's nothing wrong with it. All the knobs work and do what they are intended to, just sounds really dark and not very loud. There is some boost available but not what I would expect from what is hailed as a great booster. Maybe that's just how this thing is supposed to sound? I'm playing through a clean solid state amp so maybe that's my problem. I also subbed 2k resistors for the 1.5k spec for R5 and R13, about to swap those to see if it changes anything.

sorry! I didn't see the link on the first read. great info, thanks!

Read the "how it works" section in here, starting near the block quote on page 7.

Right, re-read the OP, in it I rephrase the info from the build doc. I'm trying to get more info and learn more about how and why.

I seems we've hit datasheet bedrock tho (thanks somnif!)... control current input...hmm. I will dig into the datasheet.

Hello again! Really dug this extra filtered pt2399 circuit. Built mine with a fx loop and master volume.

Just a curiosity about the D2 LED across pins 7 and 3. the build doc says its there to reduce distortion at the input... but Pin 7 is not the input and pin 3 is ground.

So whats really going on here?

And can this be used to some benefit/effect in any other PT2399 circuit?

Found the prob! R11 and 12... Gotta pull down the signal there or it will whine!

Am currently playing with a crossover distortion diode "gate" in series with r11

Good to know! Thanks!

Well this is my first post here, might as well show my ass. Have built hundreds of pedals, worked proffessionally in music electronics for 7 years... About ready to throw this pcb in the trash.

The circuit works and passes signal, only problem is there is a constant squeeeeel at about 3khz... Like the input and output are connected forming a feedback loop... Only there is no such physical connection. Have tried pcb without bypass switching and the problem is definitely on the pcb. I noticed the output trace runs directly underneath the input components... Wtf!? High gain circuit pcb layout fail! When signals are in phase with each other you don't run traces like that!!! Curious if anyone else has built one of these thin sale pigbutt boards with success.

Subbed some resistor values for what I had on hand, stayed "close enough" imo. Kept the fixed gain resistors in op amp stages to have gain equal to or less than stock.

Voltages are all good and closely match spec'd values on the instructions.