3. "Switch Witch" Programmable Relay Loop Switcher
(Update: I blew the chip :) and I don't seem to have all the source code now. But I have the B.C. Rich box in the mail. So I might give it another try. OK, the BC Rich has no relays, presumably JFET switching, huge component count)
graphic
Features:
  • 2 banks of 12 loop patches switched by DPDT relays, selected by footswitches.
  • Scalable - you can have fewer loop patches, by simply omitting switches and relays.
  • Programmable, the chip remembers the program when power is removed
  • Relays can do any kind of switching you like, easy to understand.
  • True Bypass.
  • Reconfigure by rewiring the relays.
  • Easy to build 1-Chip construction.
Stomp on a button, and a pre-programmed combination of pedals spring into action. Now you can actually use your collection of pedals that you keep under the bed. Above is an artist's impression. You may be able to do some amp channel switching too.
This is a box with up to 12 footswitches and up to 12 relays. Each footswitch can patch in different settings for the 12 relays. So you can plug in 12 pedals and control them like one of those digital multieffects boxes. Plus you get "True Bypass" switching for all 12 pedals. 12 relays, 12 stomp switches and 24 jack sockets cost over $100, so you might be content with half that number.
The computerized electronics costs about $10, welcome to the 21st century.
Analog Man used to sell B.C. Rich EMP-45s for a mere US$55. Good deal, with 4 loops. But they don't seem to make them any more so I designed a 12 loop, true bypass programmable loop switcher. Effect order is fixed, but you can have an 11- loop version with the extra relay switching two loops around. The unit uses a microprocessor which remembers your programming even when all power is removed. Power is an external 8 to 12VDC supply, since the relays use a lot of current (140mW each).