Obsoletetechnology Music, Electronics and Repairs


Page and personal logbook about electronic music, vintage music electronics, DiY, repairs and midi stuff.

For Obsoletetechnology Music, visit the Obsoletetechnology Soundcloud page.


Added a page about reading out the PROM memory ic’s of an Ursa Major Space Station SST282: (November 2017)


New Obsoletetechnology mixtape on Soundcloud: (October 2017)

A selection of tunes for September.

Added Bang&Olufsen Beovox 80.2 Speaker Re-Foaming: (October 2017)

BEOVOX S80.2 Foam Edge Replacement

Added Univox Mini-Korg power supply repair: (July 2017)

Univox Mini-Korg 700 MK2

Added Pro-Ject DebutIII repair: (January 2017)

Pro-Ject DebutIII Turntable Repair

Pro-Ject Speed Box PCB

True Bypass Module (October 2015):

4 Channel true bypass module

This is a simple relay based true bypass module for 4 channels of audio. It has been designed to handle 4 balanced audio channels, which means that it could also be used as an 4 channel unbalanced stereo bypass switch.

Midi Filter Tool (December 2014):

PCB fully assembled

This device allows the filtering of midi messages on the midi bus. The unit provides a wide variety of configurations while only requiring a very basic user interface.

The unit is designed as a low cost/low part count device targeted at diy-building and is based on a pic16f1829 microcontroller running at 32Mhz.

Utilization examples:

Latest Obsoletetechnology Dj Set: (August 2014):

Little mix session while selecting records for the Villa Wuller Obsoletetechnology Dj Set.
100% pure Vinyl.
With tracks from artists like 4 Most Poets, Prosumer, Master C&J, Levon Vincent, Blackjazz Consortium, Rebel Alliance, Quantec, Conforce and more.


Record release on ROHS! Records: (03 February 2014)

A new Obsoletetechnology mini-album ‘Radiant’ now available on pre-order from ROHS! Records:

Edition of 50 limited hand-numbered printed CD-rs. All copies comes in a plastic clam shell cases.Includes immediate download of 5-track album in the high-quality format of your choice (MP3, FLAC, and more), plus unlimited mobile access using the free Bandcamp listening app.

Shipping out on or around 25 February 2014 http://rohsrecords.bandcamp.com/album/rohs-007-cd-obsoletetechnology-radiant

New Project Added: (01 January 2014)

CV-Gate To Midi Converter

Low cost CV-Gate to Midi converter allowing to convert analog CV-Gate and CV signals into Midi Note On/Off and Midi CC messages.

CV/Gate to Midi Prototype Wiring (Front)


Newly fixed:(16 April 2013)

Sequential Circuits Prophet VS

SCI Prophet VS Frontpanel

Added 2 more repairs: (25 March 2013)

Elka Synthex Fan replacement

Power Supply with new Fan

Roland VP330 Vocoder Compressor circuit

VP330 Frontpanel

New EP released on Gotwax!

The second gotwax! EP is a slamming longsided club two-tracker with detroit- and dub-flavoured raw-body-music. The future as it used to be!

Gotwax! 002 – Obosoletetechnology
Sleeve Front

Preview Tracks:

New repair added for a Yamaha CS5 Synthesizer (11/11/2012)

Yamaha C5 Frontpanel #2


Lately repaired: (11/05/2012)

Juno-106 Synthesizer

VCF-VCA replacement due on two voices.

Roland Juno-106


New project added: (07/01/2012)

Midi to Trigger Interface

This Midi to Trigger interface generates a TTL (5V) trigger signal per note over a range of ten notes. It can be used for example as a midi interface for vintage drum-expanders or as a multiple-trigger generator for a modular synthesizer.


New project added: (04/01/2012)

Tama TS305 Midi Trigger Modification

The Tama TS305 drum-expander, which is a great sounding machine but unfortunately totally lacking of midi control.


Newly fixed: (19 nov/2011)

TR-808 Handclap circuit repair/BA662 replacement

TR-808 needing repair.


TR-606 power supply repair and switch replacement.

TR-606: Repair done.


New project added:(01 nov/2011)

DC-DC converter based bipolar power supply for effect units and portable devices.

Some circuits require a bipolar power supply. In a portable unit like an effect pedal, that can sometimes be troublesome, since it is likely that we want to power our effects with a standard 9V or 12V wall-wart or batteries and don’t like the idea of putting an AC mains transformer plus rectifiers and filtering into our boxes. That’s where a Dc-Dc converter based circuit can be an alternative:

DC-DC converter based bipolar power supply


Project Updated: (01/10/2011)

New firmware version for the Midi-CV/Gate converter. The new firmware allows CC Controller assignement and individual CC Midi channel selection.

See updated project here.

Midi CV/Gate converter


Lately repaired:


Another TR-909 for repair on the Bench. This is actually the 4th TR-909 I am repairing! It came with a problem on the bass drum ‘Attack’ parameter, turning the knob wouldn’t do anything. I thought this would be an easy one and a good cleaning of the potentiometer would cure the problem but not so…

TR-909 Inside

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