Rhythm Ace FR6 uniPulse install

This manual describes how to add velocity sensitive midi to the Rhythm Ace FR6 using uniPulse.

Picture via Matrixsynth

This was not tested, the manual is only based on the schematics available. If you have installed this, please be so kind and send us pictures.

Configuration file is here. (Right click, save-as)


The picture below shows the trigger point locations. Just solder uniPulse wires P1 – P8 to these points.

uniPulse power

Solder unipulse wire V+ to the V+ point shown in the picture below. Solder uniPulse GND to the V- point.

Clock and sync

It is not impossible to also sync the FR6 to midi clock. It is however rather complicated and involves quite a few extra parts. If you are interested please write us and we will provide instructions.

Rhythm Ace FR-1 uniPulse install

This manual shows how to connect uniPulse to the Ace Tone Rhythm Ace FR-1. It is possible to control all 10 drum voices via midi and they are velocity sensitive.
It is even possible to control the Brush sound in a velocity sensitive way.


Here you can see the voice board with the connections of uniPulse triggers P1-P10. The brush control needs a general purpose PNP transistor such as BC557 and a 56k resistor. Connect them them just the way it shown in the picture.

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Rhythm Ace FR2 uniPulse install

This manual describes how to install uniPulse in the Rhythm Ace FR2L

This is based on the schematics and has not been tested yet. Please let us know if you have installed it. Bonus points if you send us a video of the drum machine in action 🙂
Download the uniPulse Configurator file for Rhythm Ace FR2L

uniPulse power

In order to power the uniPulse, you need to install a few additonal components. Due to the high voltage after the transformer, an additional 15V regulator must be used (7815). The capacitors should have a voltage rating of at least 35V, more is ok. Connect the uniPulse V+ and V- wires as shown in the picture.


Trigger are very straight forward. Most triggers are soldered to the legs of diodes on the voice boards. Cymbal and Maracas triggers are simply connected to the solder points on the voice boards. It is also possible to control the Brush (B), but without testing it is hard to tell exactly how. This will be updated as soon as this information is available.

Clock sync

As always syncing the drum machine to the midi clock is optional and requires additional circuitry.
A level shifter is needed for the start/stop signal. Two pole switch (included in the kit) is used to switch between internal clock and midi clock. In order to access points A and B, desolder one leg of R12. A is connected to the resistor, B is connected to the board where the resistor was connected originally.
Point C can be directly connected to the Start/Stop switch.

ELKA Drummer One uniPulse installation

This manual shows how to install uniPulse in the ELKA Drummer One and thus allows to trigger voices via midi and to sync the Drummer One to midi Clock.

Thank you very much to Thomas Kayser of SynthMedic for figuring this out and providing pictures.

After installation use the Config Tool to upload the Config file for ELKA Drummer One (right click, save as).

Connecting trigger points

Below you can see the installed uniPulse. Trigger points are on the right the picture below shows the trigger points in a bit more detail. Two of the triggers needed additional 1Meg resistors to ground which can also be seen in the picture. UniPulse channels 1-9 are used.

Midi Clock Sync

If you like, you can also sync the Drummer One to midi clock. This requires a bit of additional circuitry. A two-pole switch is used to switch between internal and midi clock. This switch is provided with the uniPulse kit since uniPulse MK2. You will also need two general purpose NPN Transistors and 2x10k and 2×2.7k resistors. The circuit can be seen below. Its purpose is to level shift the clock and gate voltages.

The GATE signal is connected to uniPulse pin D1, the CLOCK signal to uniPulse pin D2.
The picture below shows the location of the C point and the circuit on a prefboard. To access points A and B, one leg of a capacitor needs to be desoldered. This is also shown in the picture below and in more detail in the next picture.

Installing the uniPulse board

You can mount the uniPulse board in the case using distancers as shown here:

The Drummer One needs to be in start mode with all Rhythms deselected in order to be synced to midi.

uniPulse MK2 is here

uniPulse has been updated to a new improved MK2 version, while the price stays the same.

These are the improvements:

  • Larger output voltage range: +-15V
  • Wider supply voltage range: runs from 7V-25V, generates +-15V supply voltages internally
  • 3 additional digital outputs
  • Improved input and output protection
  • Fully compatible with uniPulse MK1
  • Comes with an external midi socket with wire and connector
  • Now also included in the kit:
    • A two-pole throw switch often needed to switch between internal and midi clock
    • A panel mount learn button which can optionally be installed