Aleph Null Special Sauce

 I'm a big fan of Brian's, aka Aleph Null's, circuit designs he's been kind enough to share over on the MadBean forum. Here's one of his latest offerings, the Special Sauce. In his own words, "It's a short delay with envelop control pitch bending. This makes for unique chorus, doubling, slap back, and vibrato effects." More info here.

EHX Small Clone

 The blog needs more modulation, so here's the classic EHX Small Clone chorus. Made famous by Kurt Cobain, the Small Clone has a wide range of chorus tones. I've laid it out two ways, one stock, and one with the Depth switch replaced with a pot. You can probably squeeze this into a 1590B, but I'd stick with a 125B if you want the board mounted to the pot(s). Schematic for reference.

Dimension P Chorus

Had a request for this one and didn't feel like laying out another overdrive. So here you go. It's a chorus using a pair of PT2399 design to emulate the Boss Dimension C designed by Distorque. Original design thread here, schematic here for reference. I've laid it out for board mounted pots and will fit in a 125B with top mounted jacks.

MXR Micro Chorus

The originals used a now nearly unobtainable SAD512D chip, but the wizards on FSB converted it to work with an MN3007. Now that those are also hard to get a hold of, I've laid this out for an MN 3207–which is almost the same as the 3007, just with a slightly different pinout for power and ground. But if you want to use a 3007, I've included a daughter board that will let you use it (it will also work to use a 3207 in place of a 3007). This will best fit in a 125B and the schematic can be found here.

Valve Wizard Jenny Greenteeth

Here's a weird chorus from Valve Wizard based around a PT2399. In Merlin's own words...

Chorus is created by passing the signal through a very short delay line, somewhere between about 8ms and 25ms. The delay time is modulated and the delayed signal is mixed back with the original un-delayed signal. Some feedback ('repeats') is often applied too, to thicken the effect. The PT2399 has a minimum delay time of about 25ms, which is just short enough to do a thick chorus effect. The more subtle chorus effects that a 'proper' chorus pedal would do are not available as they require shorter delay times ( but I'm one of those people who only ever wants his chorus thick!). However, as well as getting chorus I soon found that various other unexpected effects could also be had for free, including pitch bend and a kind of ring modulation. That's why I've called it 'weird chorus'.

It will fit in a 125B with top mounted jacks easily, but it's narrow enough that it will fit in a 1590B, but probably without the pots board mounted. Here's the original build doc with the schematic and Merlin's original layout.

Mid-Fi Electronics Pitch Pirate

Here's the Pitch Pirate with board mounted pots. Like the Deluxe version, the LFO is designed to be grounded when the effect is turned on (hence the pad at the top of the board). Just use the true-bypass wiring diagram in the General Layout Notes and leave out the LED wiring. Then just connect the corresponding pads on the board to the lugs of the switch. The on/off indicator LED (pads at the top of the board) is connected to the LFO ground so that will turn on and off (and show the rate) with the LFO. It'll fit just fine in a 125B with top mounted jacks, but will also fit in a 1590B if you wire the pots off board (or maybe with long leg pots mounted to the component side? YMMV).

Zombie Chorus

Got a request for this one. This was originally designed by John Hollis and has since been modified by various folks in the DIY community. Like the latest version of the Little Angel chorus, it has a switch to do either vibrato or chorus tones. And the Mode switch allows for different speeds (Leslie, Normal, and Clone). Here's the schematic for reference.

Little Angel V4

Had a request for this one and ended up drawing it up in Eagle. Rick Holt (frequencycentral) over on DIYSB designed this chorus and this is the latest version. It differs from earlier version with 2 toggle switches: One changes the effect from chorus to more of a vibe, and the other changes the sound (Space/Warble). I've also uploaded this to OSHPark if anyone is want's a fabricated board of this one. Best fit will probably be in a 125B.

Little Angel Chorus

Here's a simple, fairly low parts count chorus based around a PT2399, designed by Rick Holt (aka Frequency Central) from the DIYStompboxes forum. I've drawn 2 versions, one with board-mounted pots, and one off-board pots. The 2nd IC (NE5532 in the layout) can be any dual op-amp (a TL072 works well), just socket and experiment. The board is fairly large, so you might want to use long leg right angle PCB mount pots and mount them from the component side to save space. Here's a quick sound sample.

Mid-Fi Deluxe Pitch Pirate

This was a request from my friend Cody from They Remained Silent blog. The Pitch Pirate is a vibrato/chorus pedal, and the deluxe version adds a PT2399 based delay. It also has the ability to modulate over an octave as well as control the waveform of the modulator, giving you a huge range of tonal options.

Notes:
You can go the home-brew route and put a 1M LDR and LED in some shrink tubing or there should be enough space to use a VTL5C2 photocoupler. Adjust the trimmer at input till there's no unwanted distortion.

Valve WizardEntropy Chorus

Stumbled across this effect while looking for a completely different schematic. It's a low cost chorus designed by Merlin Blencowe (here's his schematic for reference), using a PT2399. It generates deep modulation and a very thick warble (here's a sound clip).