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...a hypothetical non-superbright simulation LED with a peak brightness at 10mA, i guess... multiply the resistor values by 10 to get a peak 1mA current

like so? https://tinyurl.com/25sytpmp

it bleeds off the bias current so that it goes to zero at the bottom of the sweep. i took the idea from the tremulus lune.

here's a simpler version of the LFO LED. if you're re-designing the circuit from scratch there are several other options you could go with as we've discussed previously in this thread, but if you just want to modify an existing pedal or PCB, this is probably the easiest way to do it while having...

here's the simpler version of the circuit i was alluding to in my previous post: https://tinyurl.com/2cp9mnko

i posted about a circuit that will work and will throb with the LFO shape and not just blink, on this thread. chuck replied that if he had to add a second op amp anyway then he'd just build a CE-2 style 2-op-amp triangle wave LFO which can drive an LED just as-is. if you don't want to build a...

can you elaborate on this?

i'm looking at the BE-OD schematic right now -- any idea why the bias for the first stage is set through an unbuffered VREF?

i'm working on a pedal design that uses VREF both as a bias voltage and as a signal ground -- not an uncommon arrangement as i understand it. i want to avoid all crosstalk between signals being sent to ground and op amps using VREF for their bias voltage, and an unbuffered VREF would use a large...

okay i didn't know that, that is indeed intriguing. i have a different LFO designed (again only in falstad, haven't had a chance to put it on the breadboard) that, similar to the TR-2 or sea machine/space spiral LFO, variably clips the waveform so you can go continuously from shark-triangle to...

sure, but adding an entirely new digital LFO chip is a whole different thing. my goal with mods on classic pedals is to still be able to access all of the classic sounds (ideally by setting the knobs to noon or one or the other extreme) but having many more usable options available. so in the...

i haven't built it yet, i'm away at a cabin right now which gives me lots of time for theoretical circuit building but no ability to build practical ones. doing it as a 2-op amp true-triangle LFO makes sense. i've heard people say that the slightly exponential "shark fin" shape of the single-op...

so this is a nut i've been trying to crack for a while. almost every approach i've seen published has taken the signal from pin 7 -- the square wave output of the op amp -- as their starting point. some use a capacitor to smooth it out but the problem with that is that the capacitor's value is...

since the "throb" LED takes its input as pin 7, the square wave output of the op amp. am i correct in assuming that it will only blink in time with the rate and not ramp up and down like the triangle wave output of the LFO? because if so i think i have something valuable to contribute and not...

did you end up doing the PH-1? i'm working on the PH-1R right now and would love to hear your insights

and another question: as i understand it it's standard best practice so isolate the power supply for the LFO from the rest of the circuit so as to avoid crossover "tick", and yet in the phase 90 and PH-1R that isn't the case, nor have you felt the need to do so in your pretty extensive redesign...

could you clarify what the COLOUR (appreciate the non-americanized spelling on that one btw) control does? it seems like it replaced the RANGE trimmer, which from the name makes me think it shifts the sweep toward the treble or bass end? am i right?

^this is the RG keen panner circuit i was referring to in my posts. if you download his .pdf on it you can understand how and why the circuit works and adapt it for your purposes

this method will work but it's taking the square wave output of the op amp so the LED will only blink in time with the rate, it will not swell or throb or ramp the way the LFO's triangle wave output does

i've been thinking about how i can get better headroom out of this pedal. the clipping cap is allowing a lot of bass to pass through the clipping stage at full volume and if it isn't clipping the op amp at that stage, it definitely will if it's boosted in the tone section. and as much as i do...