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

Unlike with the DR55, instead of repeatedly attempting to program a pattern only to find that you messed up the bassdrum on the 16th step so you have to start all over again, the sounds and accent on the CB55 board are triggered externally using standard trigger pulses. With the optional trigger conditioning circuit installed you can use also use gate signals, or trigger pulses longer than 10ms. 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. These could be sourced from a midi to trigger or gate converter, another drum machine with a trigger output, a modular synth, or some other bit of kit capable of producing the appropriate triggers.

This is just the bare unpopulated PCB. We do not supply kits for the full build.

Once you've populated the board, it needs very little in the way of setup. Theres nothing complex to go wrong, so as long as you are careful with your soldering theres no reason why this shouldn't be a beginners project.

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

Below are some links to demos of this board in action. This is the basic board with no mods. You may hear some minor background hum/noise at some points on the first demo. This is due to the idiot recording the demos cleverly touching the tone and accent pot pins with their fingers while adjusting them. Rest assured that they have been severely punished ;-)

DEMO1

DEMO1