Ultimate Percussion K2-X

Ultimate Percussion KP-X analog drum synth
Ultimate Percussion KP-X drum synth

This is a very rare 8-channel analog drum synth from the 1980s. The person who brought it over told me it was designed in Germany, built in the UK and sold only in those two countries. There is very, very little info on it on the internet, and of course no service manual or schematics, but luckily all the voices are the same. The main problem was caused by the failure of the VCA in Channel 1.

It’s a good, fun drum synth, but hard to jam on without the right gear — it has no internal sequencer, just 6 particularly underwhelming preset patterns that only use 3 of the voices, so you have to sequence it via its 8 separate trigger inputs.  It would be a great modular companion.  The sounds are simple and very 80s.  The panel actually bears the declaration “Super Analogue” and it definitely is.  It really wants to make those POONG! 80s tom sounds.

I started making a schematic of the drum voice in this synth but didn’t get a chance to finish before it got picked up by its owner. If I ever get one of these in the shop, I’d love to finish and build a clone. I’m dreaming of building a modular drum synth whose voices include clones of all different classic drum synth voices.

Service Tips: delicate pads on this one, desolder at low temperatures

Work done: replaced CA3080 transconductance op amp and LM-324 op amp to revive Channel 1, replaced two electrolytic capacitors in Channel 1.  Replaced electrolytic capacitors in power supply, cleaned out pots, washed knobs and cleaned/vacuumed everything else.

Leave a Reply

Your email address will not be published. Required fields are marked *