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☰ Buchla 100 Modules:

Model 111 Dual Ring Modulator

Two independent ring modulators. Each output consists of the sums and differences between frequency components of two input signals. Original signals are suppressed about 55 dB.

DIY Resources

  • Schematics:
  • Errata:
    • On the CBS schematic, R38 and R89 (47Ω) should be tied from Q8/Q28 to V+ (instead of back to a couple of other transistors). The schematic on LA67's site shows this correctly. This is correct on our PCB.
    • The output caps (C4, C5, C21, C22) are shown as 56uf on the CBS schematic, they should be 5.6uf (tantalum in the original). Our PCB shows correct values.
    • On some versions of the schematic R19/R70 is shown as 10Ω - it should be 10k, matching R14/R65.
  • Builds: David Brown's essential build/repair notes, including mods and trimming instructions.
  • PCBs: I offer Printed circuit boards for this module (2 PCBs required for a dual unit); FPD files also available for making panels.