TD-3 Suboctave

Simple and proper suboctave mod for the TD 3. The 4024 CMOS counter is hotglued to the PCB bottom up (that poor bug) so that pin 1 is on the upper right. Instructions:

  • 1: to saw via 1M resistor and 1n cap
  • 2 and 7: ground
  • 14: 9 V
  • 12: to mixing point via 10k to 100k log (or lin, but log is better) pot, 100k resistor and a 100n to 1u cap.

It makes use of the internal protection diodes in conjunction with the resistor and cap at pin 1 to get the right levels for the 4024 so it should work reliable. Enjoy!