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.

John Hollis Ultra Flanger

Got a request for a flanger effect, and hadn't seen many layouts for the John Hollis Ultra Flanger (that didn't have tiny thin traces anyway), so I thought I'd give it a go. For the record: flangers are hard. I knew from the get go this one wouldn't fit in a 1590B, but it will fit nicely in a 1590BB. There's empty space at the top corners you can cut into to fit around the screw posts in the corners of the enclosure if you need to. Here's the schematic and here's what John had to say about the circuit:

I was originally going to develop a minimum part count version of the EH Electric Mistress. Instead I went for a something with the versatility of an MXR flanger and the extra wide sweep that the A/DA flanger was known for. It needed an extra chip to get the wide sweep but it's worth it. Current consumption is very reasonable at around 2 to 8 milliamps dependent upon clock frequency.

Update Aug. 3, 2016:

Fixed the connections from the MN3007 to CD4049. Note jumper under CD4049.

Hollis Flatline Optical Compressor

Here's a good, subtle sounding compressor. It uses a LDR and LED to control the limiting done by the effect. You can go the home-brew route and put a LDR and LED in some shrink tubing or there should be enough space to use a VTL5C2 or a NSL-32 photocoupler. Diodes I've listed as 1N34s but any germanium diodes should work.