Sequential Circuits Prophet VS Reparatur Service
13. September 2020
Yamaha CS-30 Reparatur: Nichicon MUSE statt Matsushita-Elkos
27. September 2020
This Arp Odyssey came in for restoration. The main issue was the keyboard. It didn't play all notes. Some were kinda double triggering. Some produced tunig glitches. The problem with these keyboards is the oxidation of the contacts. The picture is a close up from the "bus bar", thats the name for a thick wire that runs thru the keyboard and hit by smaller wire from each key pressed.
The single keys also were quite noisy (clatter) when playing and the feel wasn't really good. Far away from the smooth feeling a keyboard player usually should feel. This is caused by dried, so called "key bushings". These are made out of a soft material which hardens over time. Whenever you press a key it's like pushing hard to the metal. Next picture shows the more white looking hard key bushings.
For both, cleaning the contacts and replacing the key bushings I had to disassemble the whole keyboard. While I was in here I removed some rust and I cleaned/washed the keys. After such a long time I don´t want to know, what that dirt is about. Now it's clean and safe and it can be played again without getting sick ;)
Someone worked on this Arp before. It already hat a new psu, new caps and faders were cleaned. Not very well. So I did some improved cleaning on some faders/sliders. I also cleaned the jacks on the back, the housing and -of course- the frontpanel.
Last but not least there was some very high frequency going on in the resonance. I fixed that by calibrating the synthesizer.
Now its future proofed for the next musicproduction or even for a live performance.
Caution
There are lethal voltage exposed in electronic devices. Unless you know what you are doing, don’t try this. If you following along, you doing so at your own risk.
I’m documenting repairs for my reference and yours.
I do synth restorations and repair with a specialty in vintage synthesizers, drum computer and other vintage gear, based in Düsseldorf, GER. Get in touch about your synth situation!
