Ages ago I’d read that there were originally going to be more modules in the original Roland System 100 series, but nothing further was released (probably in Gordon Reid’s excellent History of Roland)
I hadn’t seen anything more about this until I spotted this brochure on eBay (long gone now) for the original units, with the following:
Also planned for the near future are: Audio Delay unit, Stereo Phaser, VCO bank, and other units.
…so maybe, 105 Audio Delay, 106 Stereo Phaser and 107 VCO Bank?
I could imagine the delay and the phaser being similar circuits to the equivalents in the 700, but I can’t think how they would have been designed to stack up on the System 100 – the top of the 102 isn’t particularly deep. Maybe this was part of the reasoning that led them to design the 100m?
Having given up trying to hand solder the SOT-363 bits on the OpenMusicLabs BA662 clone/clown, here’s a version with BCM847DS/BCM857DS transistors instead of the dust-like PMP4201/5201.
No idea if it’ll work. The specs look almost identical, apart from a tighter hfe tolerance on the smaller device which I don’t think will matter anyway.