RolyControl is a hack to control the defeat, hold, and tap-tempo, and preset functions of the Roland SDE-1000 rack delay unit. (Great unit.) I built this out of the stomp switches from my Peavey Amp, a box, miscellaneous wire/plugs/jacks, a couple more stomp switches bought from Antique Electronic Supply, some Velcro, the ubiquitous plexiglass, rubber feet, and some wood. The two switches on the Peavey part simply function as Defeat and Hold; the other two control either preset switching or the tap-tempo feature, depending. (Bear with me here a moment, a couple pictures would help but I haven’t got them yet.)
On the back of the Delay unit there are two 1/4″ jacks, one for a preset switching switch (labeled ‘Preset’), and one for a tap-tempo switch (labeled ‘Playmate’, I think). If you have a switch (momentary) connected to only one, that one works great but you can’t access the other. But if you plug them both in weird things happen. I eventually figured out, after a bit trial and error, that with a jack plugged into both you can use one or the other by latching closed (‘shorting’) the switch of the one you don’t want.
So, one could simply make a box for each, with a momentary switch and a latching one, so the momentary switch does what you’d think it would and the other one defeats it and lets you use the other function. That, however, is entirely too convoluted (even for me), because in order to switch functions you have to latch one and unlatch the other, and if you either latch or unlatch both at the same time headaches ensue. (Got all that?)
So naturally, you use one momentary switch to do the function you want and a latching one to select which function the momentary switch will do. Right? Of course right. The basic idea is that you have a latching DPDT switch that, in one position, connects the momentary switch to one jack and shorts the other one. And then when pressed, it reverses the jack connections. The concept is roughly similar to the StompMuter, but a bit different in execution. It works pretty nicely.
That’s two switches. The other two (the one’s that think they’re supposed to be Peavey Amp channel/reverb switches) control Defeat and Hold. Need pictures.
Just to comment on the switches – I bought the El Cheapo $5 ones (from the link above) and they hold up all right. They don’t have as nice a feel and work OK for general use, but they’re definitely not heavy-duty and may get funky after a couple years of good use.