circuitbenders.co.uk

RECYCLING NOISE SINCE 2001

The circuitbenders.co.uk CB55 is an exact clone of the voice board of the Boss DR55 drum machine. It has the four fully analogue percussion sounds, bass drum, hat, snare, and rimshot, but leaves out the clunky and arguably useless sequencer. There is also an overall accent feature that adds a little extra punch to the whole mix when it is triggered.

This is the new v1.1 board which has a couple of minor improvements in the layout to make it easier to install individual outputs for the sounds.

To get any sound out of this board once you have built it, you will have to have a source of +5v trigger signals or gates to drive it. With the optional trigger conditioning circuit installed you can use also use gate signals, or trigger pulses longer than 10ms. These could be sourced from a midi to trigger or gate converter, another drum machine with a trigger output such as a TR707 or DR110, a modular synth, or some other bit of kit capable of producing the appropriate triggers.

You can download the build guide and parts list from HERE. There is also a dedicated board on our forum for any build queries you may have, or potential mods you want to suggest and discuss. To take a look click HERE. The schematic is also available via the forum.

You can find a short demo recording of this board in action on soundcloud HERE

This is just the bare unpopulated PCB. We do not supply kits for the full build, but you can find nearly everything you'll need at very good prices and with cheap fast shipping at Tayda Electronics in Thailand. Alternatively we can recommend CPC or Farnell in the UK, or Mouser and Digikey in the US. No doubt there are dozens or more suppliers that could be used, but you may find that some of the smaller sellers have difficulty with some of the more esoteric cap values, which is the main benefit of Tayda, as they tend to have all of them.

The board needs a +12v power supply. Please note that due to its size (139mm x 72mm), this PCB is not designed specifically to be used in a eurorack modular system, but we have included a eurorack power connector just in case somebody wanted to try and kludge something together. We have seen several successful eurorack builds using these PCB's.