Rebote Delay - 1590A

For those of you who didn't want 1590A week to end last month, here's another mini layout for you. It's an early iteration of the Rebote Delay that features a simple JFET stage at the input, followed by the PT2399 delay stage. Simple, yet effective. Note: mind the 3 electrolytic caps on their sides in the middle of the board. Here's the schematic for reference.

CMAT Mods Butah

Here's a Blues Breaker variation from CMAT Mods. Seems to be a blend of the original and second versions of the Blues Breaker. Originals use a 1N4148 for polarity protection, but a 1N5817 would be better. It's laid out for board mounted pots and will fit in a 1590G if you're into those.

One-Knobber Project

I haven't made a detailed project in a while, so for Fuzz Friday here's the One-Knobber. It's based on the old Dr. Tony Balls stripboard layout that covered the ColorSound One-Knob, D*A*M Meathead and Dark Meathead, and a one-knob adaptation of the '66 Vox ToneBender, and I've added the Ritual fuzz by Black Arts Toneworks.

Project PDF

555 Relay Bypass

I know there are a bunch of you out there who like your 555 timers, so this one's for you guys. This relay bypass uses a 555 as a bistable flip-flop combined with a simple relay trigger designed by MicTester. His original design uses a latching footswitch, but with the addition of the 555, a momentary switch can be used for a soft touch bypass. MicTester says that the relay must be a Takimisawa AL5WN-K, but they are easily found on eBay and other vendors. Schematic and further discussion can be found here.

Keeley 4-Knob Compressor

The Keeley 4-Knob Compressor is a modified Ross Compressor and is highly regarded in the stompbox world. It's only down side is the use of the obsolete CA3080 chip. These can be hard to find and a little pricy. However if you're unable to find one, or unwilling to pay for one, use the LM13700 chip (which is 2 3080s in one) and this conversion daughter board. The schematic can be found here. If you have a hard time getting 150k pots, use a 250k pot with a 390k resistor in parallel (between lugs 1 and 3).

Galactic Fissure

I thought I'd close out Synth week with a fuzz designed specifically for synths. (Fuzz Friday waits for no man!) This one is pretty straight forward and I don't have much to say about it. Schematic can be found here. I added a pull down resistor to the input in case some one builds it for guitar, as well as polarity protection and power filtering.

Devil's Triangle Drone

Here's a synth circuit from Paul in the Lab (schematic and sound samples can be found over there). I've laid it out for board mounted pots with the board vertically in the enclosure. See the drilling template in the library for a visual. Here's what Paul had to say about it:

This is a project based largely on the put up or shut up mentality, for quite some time I've been getting annoyed at seeing youtube videos of people pissing about with these "synths" which are basically boxes of 555 timers with a million knobs that make stupid noises that you couldn't ever actually use in music so I thought I would make my own little synth that would get repeatable sounds and be useful in music and what better type of synth? a droner type - basically cause I love bagpipes - I like drones.

Anyway the circuit itself is quite a simple one basically because I only designed it during the week, all it is really is 3 triangle wave generators configured to operate in the audio range going into a mixer op-amp configuration with the odd filter here and there to soften the waveforms
I've used LM358 op-amps cause they are the cheapest, I'm not too sure if others would work in the same way though they probably will.

Why call it the devils triangle - well it has 3 oscillators one of which can oscillate a slightly high pitch range (for melody) it also sounds demonic so the name fit.

If you want to implement on/off switches for each oscillator, replace these jumpers with on/off switches.