PCB versions

rev 2.e (07/2016)

  • colour: red, labelled rev 2.e
  • silkscreen corrections (75k, 560p)
  • trimpots removed
  • supported by current firmware

rev 2.d (04/2016)

  • colour: red, labelled rev 2.d
  • make everything 0805 -> move 10n caps into feedback loop
  • add CC-BY-SA licence
  • supported by current firmware

rev 2.c (12/2015)

  • colour: yellow, labelled rev 2.c
  • move mounting hole -> improve mechanical stability
  • ditch pull-up resistors (for switches, triggers)
  • ditch 78L33 regulator, use onboard 3v3 instead (3v3_D)
  • add 10k pull-up for OLED CS signal.
  • replace TL074/bat54s with MCP6004
  • supported by current firmware

Legacy versions

NB: prior to version 2.c, the input stage consisted of a TL074 (+BAT54s), not a MCP6004. other than that, the differences between recent versions are very minor. see here for the legacy BOM.

rev 2.b (07/2015)

  • colour: yellow, labelled rev.2
  • ditch the alternative (adafruit) OLED header
  • ditch alt. headers for CV signals
  • add holes (underneath the jacks)
  • supported by current firmware

rev 2.a (05/2015)

  • colour: yellow, labelled rev.2
  • use LM1117, not 7805 regulator
  • use LM4040 voltage reference, not 79L05 regulator
  • simplify output stage: replace offset trimpot with divider
  • simplify output stage: 4x single inverting op-amps
  • supported by current firmware.

rev 1 (08/2014)

  • colour: yellow, labelled rev.1
  • replace precision resistors with rheostats.
  • needs modification of the output stage to work with the current firmware.

rev 0 (06/2014)

  • colour: green, labelled 4xCV
  • unpublished