CB55 analog drum machine, 16HP eurorack build

video by Jon Petter Skagmo

CB55 is a DR55 clone pcb from circuitbenders.co.uk. You can find addtional posts featuring the CB55 here.

This one was built by http://skagmo.com

"CB55 analog drum machine (16 HP)

This one is popular to mount in Eurorack. I started off trying to make a 28 HP module, but i didn't see the needs for all the modifications/pots I planned, and I thought the module was too large, so I started over and made a narrow (16 HP) MIDI enabled module.
Based on the Circuitbenders CB55 analog drum machine PCB
Cut off the entire trigger conditioning circuit and drilled new mounting holes to allow the PCB to be placed vertically behind a Eurorack panel.
Designed a MIDI and sequencer addon with a PIC18, with a switch on the front panel to start/select predefined sequences, and a DIN-5 for MIDI in. This PCB also has the voltage regulators and power connector, as that was chopped off together with the trigger conditioning circuit.
In addition to the standard volume, tone and accent pots, there are individual volume pots and jack outputs for each of the voices.
Panel was milled from the rear side because I needed to machine some pockets for some protuding tabs on the potmeters, and then flipped over to do the engraving."

X1L3 - UNDERWURLDE - glitch and delay demo run

Published on Aug 16, 2019 X1L3

"A very 90s era NIN-alike session to serve as a demo. Fitting considering the 90s 'shadow artefact' tech the module is based on :)

The underwurlde is processing a CB55 from circuitbenders.co.uk (link at the bottom) which has been turned into a module in my rig.

What you're hearing for most of the video is the CB55 routed clean to one channel and the realtime processed sound of the wurlde routed to a second channel.

To correct an error in the video text. The third delay section is a grab with a sequenced pitch rise, not a drop. This is how the stepped drop is formed in the loop.

I wanted something familiar and simple to process to illustrate how the underwurlde can transform that basic sound into the sorts of chaotic but refined esoterics thrown out by well modified circuit bent instruments.

Most of the demo is an escallation of the Processing of the CB55. At about 5.15 the underwurlde switches over to serving as a delay.

As a delay it can pull some impressive delay times. It can also act much like an abused pt2399 delay will but with MUCH more finesse. The limit at which the noise bleed and disintigration of the delay loop is much longer, it's capable of sustaining a loop feedback without it disintigrating into noise and if the loop is ramlocked it essentially becomes an infinite delay.

Ramglitching is a spin off of the circuit bending that i've indulged in for many years now. What you have here is something akin to a bent Casio SK1 sampler. You can grab adio, lock it in ram and then abuse it with the glitch array. This is none destructive, if you release all glitch lines then the audio in ram remains intact and as it was when sampled. The main module has three glitch gates and a header at the back that allows you to configure these three gates to the eight data lines according to taste. A 4hp strip will follow some time soon which will allow all eight data lines to be merged for enhanced chaos.

The final section of the run is a sample of me going 'ahhhhhh' into a mic, which is then looped, pitch sequenced and with some restraint, glitched to a rise where the last 'chorus' section kicks in."

"UNDERWURLDE - esoteric delay/looper/glitch+texture generator - eurorack module £220.00"

First featured here.

Release date: 24-08-19

https://x1l3.bigcartel.com/

X1L3 - MIDI to gate eurorack module + NUX timecore total conversion

Published on Sep 22, 2018 X1L3

"4HP eleven output midi to gate module.

Being used here for drum sequencing duties. Starting out with the CB55 module built with the DR55 clone pcb from circuitbenders.co.uk. An elements is tied to the midi to gate to add an air of melancholy and mid way two peaks are added to escallate the track and nail down the drum section before the track starts to drop out. The last gate is reading a continuous note on/off track from the daw to create a sync clock for the NUX timecore. I alter the time signature subtly towards the end which you can hear in both how the NUX suddenly tries to shift tempo and also the slow delay fade out in the last few bars. A simple demo really, just something to show how much this little module can do. My daw is used for the melodic backing and bass etc. Too lazy to knock it up on the rig today :P

Reads incoming date on Channel ten and responds to middle C up through the next ten notes. Not on will set a gate high and hold it until the note is released, setting the gate low again.

Countless uses for this one. Clocks for anything tap tempo enabled, sequencing duties, adsr triggering etc etc.

Also in the rig here is a NUX timecore digital delay guitar pedal converted to eurorack with homebrew pcb and panel test pieces made on my 3040 cnc router.. It now has input and output buffers to make it suitable for euro level signals and a gate input on the front panel which allows you to engage and disengage the effect or send a clock to it to sync thetap tempo. Really cool delay with loads of modes and a decent sound. The CB 55 drums are fed through this throught the demo. A total conversion kit is underway for anyone wanting to mod their own :)"

X1L3 - Circuit bent casio PT30 + CBUK CB55 drum module - darkwave synth jam

Published on Apr 16, 2017 manufacturedZ3R0

"Live key jam focussed on subtle use of the delay and ruiner mods. Under pinned by a CB55 drum module built using the board available at: https://www.circuitbenders.co.uk/

Not an overly bent or warped session, but a slick example of what a bent casio can sound like when modified with some finesse.

The CB55 has some mods applied which i've documented and made available through a few avenues such as the synth diy page and my own page on facebook.

Incoming midi to the midi to gate in the eurorack is used to trigger the CB55 along with an AR generator routed to a filter which the drums are passed through. An AR generator is also routed to the filter in the PT30 to gate its filter via the cv input. The filter is gated by the AR generator through the first half and then the cutoff opened up for the melody for the latter section.

The ruiner mod is used subtly through the whole session to shift the wave form of the PT30 for an animated waveshaping/PWM type effect. In a different arena, as with the delay, it can be used to totally screw up the output of the keyboard. Which i'll show in another more extreme upload.

13 raw circuit bends - extreme pitch control - drum/chord/bass boost/mute etc etc.
Ruiner - ringmod/distortion.
Digital delay untethered to behave as a bent delay pedal would.
Sallen key resonant low pass filter.

Lacking the midi of my PT80 configuration but compensating for it with far more mods and a much wider scope on the fucked up spectrum."

Prototype MIDI-CV box for Novation Circuit

Published on Jan 2, 2016 Jason Hotchkiss

"A quick demo of sequencing analog gear using Novation Circuit and a compact MIDI-CV box I am working on. The gear used is a CB55 drum voice board (DR55 clone from circuitbenders.co.uk), Moog Minitaur, Pittsburgh Modular System 10.

The PCB shown here is a prototype, but I hope to have them on sale soon. It has a 3.5mm MIDI input jack so a simple stereo 3.5mm cable can connect it to Circuit's MIDI output. I've been working on bus powering it, but an external supply is used for this clip.

Support two mono channels with Note CV, Gate, Velocity CV (one for each Circuit synth track), and four drum gates (one for each Circuit drum track). Also an additional drum accent gate (when any
drum triggered at max MIDI velocity) which can double as a clock out.

Built around PIC16F1825 microcontroller with MCP4728 Quad 12-bit I2C DAC with on-board charge pump used to get full CV range.

I hope to have these on sale soon on my Tindie store https://www.tindie.com/stores/hotchk155/ ... watch this space

Cheers for watching!"

CIRCUITBENDERS.CO.UK CB55 - Boss DR55 Drum Machine PCB Clone

via Circuitbenders

"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.

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..."