Distortotron is an effects processor: downsampler, bitreducer and clipping overdrive. It was made in 1993 in Norway by Svein Berge and Henrik Sundt a.k.a. PSYBE for a Tromsø based musician Per Martinsen a.k.a. Mental Overdrive. The concept for such instrument came from the need to bring back the alliassing and noise of early 80s samplers and it heavily formed the sound of Mental Overdrive’s debut album Plugged released in 1995 which became the landmark of the so called Tromsø sound.  The album got re-relased in 2016 on Prins Thomas’ label Rett I FlettaThe Distortotron inspired Václav Peloušek of Bastl Instruments to design eurorack module called Tromsø.

note: Svein Berge is not the guy from Röyksopp – just has the same name.

Technical details

The potentiometers have caps made of old capacitors and the sides of the enclosure use old circuit boards as a design element.
Labels on the front panel are written in poetic Norwegian language which embodies the humor of its creators.

The Distortotron has 3 sections:

  • Quante-sprang and Ditto stoei control “quantum noise” – or in better words quantized noise which emulates loss of bitdepth of the signal – therefore it is pseudo bitreducer. It probably forces the analog signal to become only certain set of fixed voltages and adds some noise similar to the low bitrate noise.
  • Taste-rate controls pitch of downsampling – analog sample and hold circuit with oscillator to reduce the sample rate of the signal and introduces aliasing.
  • Avklippings terskel and Ditto stryke control the clipping circuit  with adjustable thresholds and amount of clipping.
  • and output volume called NIVEAU (outdated Danish word)




original documentation in Norwegian