TC Electronic Echobrain Mod
Mods: Momentary oscillation/feedback with rate control (left footswitch), time glitch (red button), expression controllable time (bottom TRS).
The oscillation/feedback mod is just a momentary footswitch (SPST) that connects a 100kA pot in parallel with the upper two lugs of the repeats pot, decreasing the resistance in the feedback loop of the delay. It can go from very slow swelling to instant feedback.
The time glitch button connects a 100kL in parallel with the lower two lugs of the time pot, momentarily lowering the delay time when engaged. Short taps results in glitches in the repeats. The TR of the TRS expression jack is connected to the same lugs, allowing expression control of the delay time. Using the 555 LDR EXP to modulate the delay time yields a dirty chorus or vibrato depending on the mix level.