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Nice work! Good to see your first attempt worked out of the blue box

Does the Blue Box use a comparator? It certainly sounds like it could be.

This is my first attempt at PCB design. I chose a simple circuit and followed along to DigiKey's KiCad tutorials.. The One Chip Pony only does one trick—and it only uses one chip!



Clown color hydro-dip finish felt appropriate.



Maybe it looks a little silly in such a large enclosure, but I needed the extra room for the giant knob! This layout was designed specifically to accommodate the knob and switch, and also to be easy to troubleshoot.



An input gain stage feeds a comparator. Instead of amplifying the signal until it clips, the signal is compared to the bias voltage. If the input is above the threshold, the output swings to the ground rail; if below, it swings to the supply rail. It's maximum fuzz and maximum compression all the time. Picking dynamics do come through a little, but as changes in timbre, not volume. The "Gate" switch is actually changing the input gain and the input impedance. More gain means less aggressive gating. The upshot of the gate is that the pedal is dead silent when you're not playing!

Here's a demo:

I have a couple extra PCBs. If anyone is interested, DM me.

Here's to a quick recovery!

Looking good from here! I can't tell you how many sins I've hidden under washers. How do you like the circuit?

If everything else is connected correctly R4 is sending negative feedback to Q1. It'll just be guitar signal. That's a lot of negative feedback, so the signal could be pretty weak, but it won't break anything.

The login issues seem to be resolved from here. I'm still getting used to the new color ways. The mobile experience is much nicer now!

I built this stock and found it to be a little noisy with my rig. This isn't a criticism per se—my amp is particularly sensitive to noise and PT2399s aren't known for their fidelity.



I received the enclosure as a Christmas gift and wanted to show off as much of it as possible. Label maker labels are encased in clear coat.



The output volume was mounted internally. The "tails" switch grounds lug 2 of the "Repeats" (or Regen) control by connecting it to lug 6 of the bypass footswitch. This grounds the output of the PT2399 when the "tails" switch is activated and the effect is bypassed.



Above is the original schematic with my values in red. R2 and R4 were changed because that's the closest value I had on hand. R3 and R13 were changed to increase the dry and delay output. Unity volume can then be achieved with a lower "Output" setting, which attenuates the noise from the PT2399 and the rate LEDs. C14 and C15 were upped to reduce the hiss in the repeats. They still have that bright bell-like quality that's the signature of this circuit, but there's no burst of white noise that you get at higher delay settings with the stock values.

On the whole, I'd recommend this circuit. I don't think most people would hear the increase in noise floor with most setups.

Looks good inside and out! How'd you manage to get the graphic over the hammer-tone paint? Was it a stamp?

I haven't done a ton of transistor tasting, but because the second transistor sends negative feedback to the first transistor in a Fuzz Face, the ratio of gain between the two transistors is more important than the absolute gain. If Q2 is roughly 1.5 the beta of Q1, you should get similar results regardless of what the beta actually is.

I had a similar issue with my build and ended up reducing R11 from 2k4 to 1k2. It definitely still squishes.

I'm seeing the reverse. It also seems to be my account.

This video came out today. I different exploration of parallel dirt.

Between the 555 and the PT2399 you have two digital clocks. The risk of heterodyning is high. That's not to say that it could be done, necessarily, but you'd have to be very careful about your layout.

Thanks. I knew the Ross had an OTA in it, but I thought it was being used as a voltage-controlled resistor—I should have looked close at the schematic. The Aphelion actually appears to be doing what I want to do; saturate the OTA. I'll definitely be looking into that.

I'm trying to understand the LM17300, but haven't been able to find much information beyond the data sheet. Explainer articles or videos all insist on using a split power rail and don't do much in the way of practical examples. Does anyone have a source that shows how to use an OTA as an amplifier (as opposed to a resistor, or in a filter)? I'm especially interested in examples of using an OTA without a split power rail.

Thanks, all. I know someone here must have some experience.