◊ PCB Documentation

111 Ring Modulator

All-discrete ring mod based on the one half of the Buchla 111 circuit. Note: original 111 was a dual; this PCB is for a single ring modulator, so you would need two for a clone project. Adapted from PCB design by vtl5c3.

PCBs are $15.00 @ — ORDER HERE

Bill of Materials (value/qty)

  • Resistors
    • 10r x 2
    • 10k x2
    • 100k x2
    • 1k5 x4
    • 220r X2
    • 2k2 x1
    • 22k x1
    • 330r x2
    • 3k3 x5
    • 33k x1
    • 47r x3
    • 680r x6 x5
    • 6k8 x4
    • 680k x1 *
    • RA 22k x2 (optional input attenuators)
    • RB 1k x2 (optional input attenuators)
  • Capacitors
    • 2n2 x2
    • 0.1uf x 1
    • 4.7uf x2
    • 5.6uf x2
    • 10uf x1
  • Transistors
    • 2n3904 x7
    • 2n3906 x3
  • Misc.
    • .100" 4-pin power header x1
    • ferrite bead x1

* Based on examining an original module, Apetechnology identified a possible error in the schematic. R27/R78 are labeled 680 on schematic, but found to be 680k in an actual module. A test build/comparison showed little if any audible difference, but I'll change the legend on the next run of PCBs. Meanwhile, this is the resistor in question: