Messages

I'm working on a multi-band compressor that would use both sides of the LM13700, but I haven't had much luck getting it to work yet. Other than that, I can't think of any circuits that use both sides. 

Can you take a picture of the actual layout? It might be an artifact of the breadboard or something.

Looking good! How do you like the screen printing service?

Welcome aboard!

jwin615 made some great recommendations. There's lots of knowledgeable people here so definitely ask away. We all remember what it's like to be new to the hobby—and there's always more to learn.

I love big knobs.
I love unruly fuzz.
I love this.
Great job and congrats on the first layout working out.
Should've dimed it in the demo though
I've been meaning to build one of these up. Breadboard one a few years back and loved it. This circuit has a bit more going on than the parasit layout. Was that you or inspiration from elsewhere?
Great job!

I wasn't aware of Parasit circuit. I did look at Anderton's comparator fuzz, but this circuit is different from that one as well.

Looks great AN.

Next up a digital echo PCB design? 

Thanks! I have PCBs for my Special Sauce circuit on the way—that's built around a PT2399, so maybe that counts? I have been side-eyeing the FV-1.

Oh I meant boards that come in JLCPCB's blue delivery box haha. But maybe you went with OshPark.

The first few pcbs I had were totally bogus or super noisy.

These are from OSHPark. I have stuff coming from JLCPCB, but that's a story for a different thread! 

It was definitely a relief to discover there was only one small error on this first board—I swapped the ground and lamp pads that go to the bypass switch—that's easily fixed!

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?