koma elektronik rh301 rhythm workstation/utility tool price : $449.00

the beating heart of the rh301 is the master clock, of which the tempo can be set by turning the tempo knob, by tapping a tempo on the tap button, by syncing it to midi, din sync or an external analog clock signal. the generated clock signal can be passed on via two clock outputs, two division outputs or via the midi output and din sync output. an incoming midi signal can also be passed along via the midi thru and midi out sockets.

and that's not all: besides having a master clock section, the rh301 is also fitted with a lfo which can be synced to the master clock, a division of the master clock, or run freely from 0,25 hz to 260 hz in five different waveforms: sine, triangle, square, s&h and noisine. this means the pedal can also be used as an lo-fi oscillator, when you turn the lfo up into the audible range. the lfo has two separate outputs on the patch bay: lfo out and lfo inverted out. some of the features of the lfo can also be modulated via control voltage, the pedal boasts cv inputs for lfo speed, lfo reset and lfo symmetry.

the third main feature of the rh301 is an envelope generator which can easily be synced to the master clock, a division of the master clock or run in loop mode. besides the normal controls for attack, decay, sustain and release the pedal comes with a range knob to change the time range of the envelope created. the envelope generator comes with a normal envelope output, but also an inverted envelope output and can be triggered by an external gate / trigger via the external gate input.

koma sensor power!
one of the features on your rh301 that you won't find in any other pedal is the possibility to control the features of the pedals with the on board motion controller. since its functions with infra red leds we call it the sensor. the motion controller can be used in many different ways. technically speaking, it emits a cv signal (control voltage) which can be patched up with any cv receptive socket on the koma pedals and f.i. on your modular system. by moving your hand over the sensor you can control the parameters of the cv input you patched it up to. with the trimmer on the back of the pedal (it says sensor) you can change the sensitivity of the motion controller.

a few examples:


rh301 as master
there are two options if you want the rh301 to be the master clock of your setup. either by setting the master sync source to tap or to free. when on tap, simply tap the large black pushbutton three times and the pedal will start in the tapped tempo and send out start / stop midi and din sync signals. if you set your pedal to free, set a tempo with the tempo knob and hit the large black pushbutton to send start / stop signals.



midi / daw as master
set the master clock source to ext and connect a midi cable from your midi host to the din/midi input on the backpanel. the rh301 now acts as your clock distribution center. you can connect din sync devices through the din out output in the back as well as use the midi thru output to hand on the unprocessed midi signal containing pitch, note on/off, aftertouch etc. and other midi information. all the analog clocks, the lfo and the envelope can be hooked up to analog synthesizers and their respective clock, cv and trigger inputs.



din sync as master
you can have your favorite old din sync drumcomputer acting as the master sync source. set the master clock source to ext and connect a din sync cable to the din/midi input on the backpanel. the rh301 will convert incoming start / stop gates to start / stop midi signals, so you can have your daw or midi sequencer start and stop in sync with your drumcomputer. all analog clock outputs, the lfo and the envelope can be connected to clock, cv and trigger inputs of your studio setu



analog clock as master
many analog synthesizers as well as modular synthesizers will send analog clocks or have trigger outputs. you can use these signals to sync the rh301 and consequentially the rest of your studio setup. connect the analog clock / trigger signal to the ext. clock input on the patchbay of the pedal and set the master clock source to ext. the internal clock of the rh301 will sync its tempo to the external source, as soon as you press the large black pushbutton the pedal will set the sync point (bar 1) on the next incoming trigger or gate. consequently the envelope will start and midi and din sync start signals will be sent.


from left to right: midi thru, din out, midi out, din/midi in (in printing visible on the top panel).

technical specifications
general specs
casing: powder coated aluminum casing, silk screened text and wooden side panels
dimensions: 23 cm x 20 cm x 5 cm (l x w x h) / 9? x 9.8? x 2? (l x w x h)
net. weight: 1000 gr / 2.2 lbs
shipping weight: 1.5 kg. / 3.3 lbs including power adapter and user manual
power requirements: 9v dc power adapter, 500ma min, center polarity negative (only use the koma adapter shipped with the pedal)


nobs, switches, sliders and led's:

tempo – rotary control to set the tempo in free mode
division – rotary switch to select one of 9 divisions/multiples of the master clock signal
source select – slide switch to select the master clock sync source (tap – free – midi / din sync / external analog clock synchronization)
rate – rotary control to change the speed / division of the lfo
shape – rotary switch to change the basic waveform of the lfo. available waveforms are: sine – triangle – square – s&h – noisine
symmetry – rotary control to change the symmetry of the lfo waveform
lfo mode – slide switch to chose between synced or hz (free running) mode for the lfo
attack – rotary control to set the attack time of the envelope
decay – rotary control to set the decay time of the envelope
sustain – rotary control to set the level of the envelope while the gate is high
release – rotary control to set the release time of the envelope
range – rotary control to change the time range on the a, d and r stages. by turning this knob clockwise the envelope becomes slower and fades from a snappy linear to a logarithmic behavior
envelope mode – slide switch to chose between master clock sync – division sync – free running mode
master tempo led – led ring around the tap/start/stop button
lfo led – led indicator to display the lfo
envelope led – led indicator to display the envelope
large black button – acts as a tap button in tap mode or as start / stop / manual sync in the other master clock modes
2 ir emitters, 1 ir receiver – calculates the distance between an object and the pedal and generates a cv signal according to the measured distance. the cv output of this sensor appears as a cv output on the patch bay, from where you can route it to the cv input of your desired, to-be-modulated feature

average clock propagation delays
midi in -> midi out < 1,2ms
midi in -> din out < 1ms
ext/din in -> midi out < 800µs
ext/din in -> din out < 600µs


the in's and out's of the rh301:

clock (x2) – master clock output; square wave signal with 50% duty cycle
division (x2) – division output; square wave signal with 50% duty cycle
ext. clock – cv input that accepts any rising edge trigger or gate
lfo speed – cv input (0v – 5v) to control the rate / division of the lfo
lfo reset – trigger/gate input that resets the lfo on the rising edge
env – cv output of the envelope signal (0v – 7.6v)
env inv – cv output of the inverted envelope signal (7.6v – 0v)
env gate – cv input for an external envelope gate or trigger
lfo – cv output for the lfo signal (0v – 7.6v)
lfo inv – cv output for the inverted lfo signal (0v – 7.6v)
lfo symm – cv input (0v – 5v) for controlling the symmetry of the lfo waveform
sensor – cv output (0v – 8v) of the onboard motion sensor for usage with cv inputs on the pedal, other koma elektronik pedals or other voltage-controlled devices

all patch bay inputs and outputs are mono 1/4" phone jacks.

back panel
dc power input – accepts standard boss style 9v power adapters, center polarity negative, 500ma min. (koma elektronik power adapter included)
cv attenuators – the sensitivity of the cv inputs can be attenuated with trimmers on the back.
din/midi in – combined din sync / midi input
midi out – midi output
din out – din sync out
midi trhu – midi thru provides the unprocessed midi signal present at the din/midi in jack