Hmm, so having had more time to play with this pedal I've noticed another glitch. When the high-pass FET is ramping up or down, there is a white noise "scratch" sound when ramping in either direction. When the FET is fully conductive there is no noise, and when fully non-conductive there i...

Cool, I'm out of town for a couple of weeks but will try to post something when I'm back. Yes, in one switch position only the left-hand LFO has any effect, and the two control signals are 180 degrees out of phase. There's no real advantage to using the BJT to phase split instead of using an inverti...

Just an update here, this version of the circuit works nicely with no clicking and little hiss. Happy with the result! If anyone cares I can post some audio clips.

Thanks again for everyone's help!

I forget now, but I believe some something like 33k? Trying to balance between excessive current draw while still holding voltage as a reference. A buffer is obviously a better way to do it. This time I was going to try a two 10k resistor voltage divider feeding the input of an voltage follower, wit...

Hey, thanks for the response! I'll give it a shot. When originally modeling the circuit in software using a voltage divider for the reference gave me some weird output from the FET variable resistors, though I never understood why, though in retrospect it was probably because I didn't buffer it with...

Tried swapping out the 100uF caps for the values suggested by Manfred, tried 10nF caps on the LFOs to reduce click as suggested by OC26, unfortunately no improvement in hiss or click. Mauman, I have a 100uF cap going from the 5V pin of the voltage regulator to the 0V pin, is that what you meant? In ...

Thanks everyone for your responses. I'll try some of these things and see how it goes, and will keep in mind the grounding convention for future schematics. OC26 - when I had the circuit laid out on a breadboard, the clicking was absent. In that situation, I had the two TL074s at opposite ends of th...

Hey, thanks for your reply! I can certainly try swapping out those capacitors. As far as ground connections, it's a little confusing as written, sorry about that. To clarify: * Power to the entire circuit is coming from a 9V DC power supply. * In all cases in the schematic, "Vcc" is +9V, &...

Hello, this is my first time posting and I'm not sure if this is the right place to do it. I tried to register with DIYstompboxes but the registration confirmation email never got through despite many attempts. I am an amateur circuit enthusiast. I designed the attached harmonic tremolo circuit from...