Repro-1 is a fierce monosynth: The classic design gives you immediate access to all the raw power: Two oscillators, self-oscillating 4-pole lowpass filter, arpeggiator, step sequencer, the unique modulation section, and five stomp-box effects which can be arranged in any order. Hard working, raw sounding and immediately playable, it's a simple and intuitive synthesizer which belies a deep feature set capable of a wide range of sounds.

Basics and history

The plug-in is a component-level model of perhaps the most powerful-sounding monophonic keyboard ever built. In the early 1980s, polyphonic synthesizers were almost within reach of the average musician. To be commercially viable, any new monophonic instrument had to be cheap but very capable. Fat drones, cutting leads, funky basses, quirky sci-fi sound effects – this synthesizer delivered on all counts.

The circuit design made good use of standard Curtis chips and the little onboard sequencer was more than just a welcome extra. Despite its molded plastic panel and the limitations of monophony, it sold surprisingly well and is generally recognized as an iconic piece of synthesizer history.

Repro-1's signal flow

Our plug-in version includes all the lovable quirks of this classic synth, but with a much more capable sequencer, lots of presets, several under-the-hood tweaks, more modulation options, and as a plus: a great collection of cute stomp-box effects.

Features

Tweaks panel

Apart from being unashamed eye-candy, the Tweaks page is there to let you change the fundamental behaviour of individual modules. There are 5 user-adjustable jumpers (mini circuit connectors) and 5 module tweak selectors. While on this page, all the main controls of the synthesizer are still accessible.

Beside the option to modify the synth's fundamental characteristics through jumpers and selectors, the panel also includes access to the Microtuning section with many included presets.

Repro-1 - Tweaks

Sequencer

The sequencer in the original hardware may have been a stroke of genius. Repro-1's version lets you step-record two patterns of up to 32 notes each, which are also saved with the preset and support copy/paste of pattern's presets between different instances of the plug-in.

Other than having more steps than the original, the integrated sequencer supports per-step velocity, a rest button to add pauses, the ability to record your own sequences through a MIDI controller, and other improvements.

Repro-1 - Sequencer

Repro-5 shares a lot of sonic DNA with Repro-1, but adds new flavours and characteristics. First: it's polyphonic! Play rich pads, shape them using the resonant lowpass filter, drive the polyphonic distortion unit as hard as you like, and finally polish your sound with five built-in effects. Keep it lush, or go for thick detuned unison leads. Repro-5 adds new dimensions to the familiar classic sound while keeping analogue authenticity front and centre.

Why Repro-5?

First we released Repro-1, a faithful component-level model of what was perhaps the mostpowerful-sounding monophonic keyboard ever built. It seemed that people liked Repro-1 so much, they wanted more… Would we please consider making it polyphonic?

After umming and ahing about the idea, we decided to give it our best. A few cuts were inevitable (for instance in Repro-1, oscillator B can modulate its own pulse width, which we gladly dropped from Repro-5). We soon realized what was happening to our new baby: It was looking more and more like its true father, a famous 5-voice polyphonic synthesizer from the same company born in 1978.

Features

Tweaks panel

Eye-candy like in Repro-1, the Tweaks page is there to let you change the fundamental behaviour of individual modules. The Repro-5 version includes 10 user-adjustable jumpers (mini circuit connectors) and 6 module tweak selectors, plus Microtuning. All the main controls of the synthesizer are also accessible.

Additionally, since Repro-5 is polyphonic, there's access to a row of 8 trimmers used to set a stereo pan position for each individual voice.

Repro-5 - Tweaks

Polyphonic distortion

While Repro-1 includes a sequencer, Repro-5 comes with a distortion unit.

Each voice has its own processor, which means there is no interaction between notes in a chord.
The distortion gets applied to the signal before the rest of the included effects.

There are four different modes available:
Soft Clip, Hard Clip, Foldback, and Corrode - a sample rate reducer and bit crusher, all-in-one.

Repro-5's distortion unit