Jiggery Pokery Sound has introduced JPS Harmonic Synthesizer, a software recreation of the extremely rare RMI Harmonic Synthesizer.
Produced in very limited quantities for a very short period in the mid-1970s, the RMI Harmonic Synthesizer is best known for its prominent role in Jean Michel Jarre’s Oxygéne. It was it was used extensively on Oxygéne (often through an Electric Mistress flanger) for basses (Parts II and IV), leads (Parts IV and V) and sequences (Part V).
The video demo for the JPS Harmonic Synthesizer is a cover of Oxygene IV, live on the JPS Harmonic Synthesizer and Combo 310U.
Here’s what they have to say about the cover:
A recreation of Jean Michel Jarre’s seminal Oxygene Part IV, solely in Reason, using virtual recreations to replace the original RMI Harmonic Synthesizer, Eminent 310U and Korg Minipops used. The main saw lead is provided by Thor.
The aim here was not to create a literal copy of the original sound (otherwise one might as well just play the original recording!) but it’s more a demonstration in the spirit.
However near-accurate recreation of the Harmonic Synthesizer should be possible with some patient adjustments and a similar effects chain. The chorus lead settings used here are taken from video footage of Jarre playing the RMI, but note that since the exact volume curve of the JPS harmonic sliders may not match the RMI (as we had to guess and therefore chose to create a nice, sensible curve that works) additional tweaking by ear would be necessary.
The JPS Harmonic Synthesizer models the original schematics of the RMI Harmonic Synthesizer, adding some new tricks to fill in the gaps of, and vastly extend, the original feature set. JPS also includes an Acidman FX Array for quick effects programming, including the all-important flanger, and a chorus based on their Chenille Chorus Ensemble.
Sixteen harmonics may not sound like very many compared to later additive hardware and soft-synths which offer 256 partials or more, but unlike those devices, the harmonics on the Harmonic Synthesizer are not pure sines: each “harmonic” was actually quite rich in other harmonics. So what looks like a limitation actually offers its own benefits—lots of harmonics but with easy programming and tweaking, making using the instrument simplicity itself to create dirty saws, all of which contributes to the raw, slightly lo-fi and truly vintage sound.
In addition, the Harmonic Synthesizer included four preset harmonic tones. In the original instrument there were 4 presets on Oscillator 1, and 3 on Oscillator 2, plus a dedicated Pulse wave generator per oscillator. What is interesting in the schematics is that it appears there was space in the design for an additional preset on each oscillator. So for the JPS RPS invented an extra preset per oscillator. You now also have “Strings” on Oscillator 1 and “Complex” on Oscillator 2, both offering more saw-like tones with an improved low end from that available via the original Reed preset alone.
- Classic RMI Digital Harmonic Generators with an all-analog audio path
- Modeled logarithmic, resistive potentiometers
- 16 harmonic level faders per oscillator allow precise harmonic adjustment
- New Shape fader allows the waveform to be adjusted from the bit-limited, rectified RMI default to a sine
- Additionally, the original design of 5-bit generators can be adjusted down to 4-bit for an even more lo-fi tone, or up to 8-bits to provide a pure (or at least, an 80’s era) sine when minimizing the Shape control
- Full analog ADSR envelope generator, with adjustable curves
- Note Off triggering option for Oscillator 2 allows you to play the note with an AHD envelope after it has been released
- Oscillator Filter, Octave Select and Tuning, and Volume level
- Oscillator 1 can now directly Ring Modulate Oscillator 2
- Independent oscillator panning
- Mono Retrigger, Mono Legato, and Polyphonic voicing options. (Up to 64 voices can be set, but they recommend 6-12 voices)
- Up to 8x oversampling removes aliasing
- Use the harmonic generators directly by adjusting the harmonic faders, or via presets. Multiple presets can be used simultaneously
- Modeled parallel resistor network
- Oscillator 1 features a Pulse generator, the four original RMI presets, plus a new and exclusive preset, “Strings”
- Oscillator 2 can be Synced to Oscillator 1, and you can select from a Pulse generator, three original RMI presets, plus another new and exclusive preset, “Complex”
- Separately adjustable vibrato and tremolo
- Syncable or free-running, mono or polyphonic LFO
- Additional CV LFO inputs can be used to over-ride the internal LFO to those targets. Combinator presets for Malstrom LFO output and a selection of third-party LFO devices are included
- Both of the RMI sequencer modes, “Up” and “Random”, are available, and for the JPS can be free-running or synced, with key hold (which in the original keyboard was obtained by literally shoving wooden sticks above the keys and into the case to hold them down!) and they also added a polyphonic gated mode!
- Colour-adjustable noise generator (pink to white) which can be used to frequency modulate the oscillators for a wide range of classic noise effects like percussion, traps, wind and thunder
- The RMI Filter is modeled using an advanced Zero-Delay Feedback analog filter, and supplies mixable Low-, Band- and High-Pass outputs
- Q/Resonance amount
- A Filter Frequency control has been added for more precise operation
- Sinusoidal LFO modulation (with external LFO over-ride option)
- Up/Down envelope sweep, with adjustable curve
- Oscillator 2 can be internally routed to the filter
- The original monophonic external audio input into the filter on the Oscillator 1 channel is also available
- The RMI features both portamento and an attack-envelope shaped pitch-bend with adjustable curve
- The JPS adds a pitch-wheel with a dual-direction range setting on each oscillator for complex and unique pitch-bend range programming; send Osc 1 pitch UP and Osc 2 pitch DOWN with just a pitch wheel up movement!
Everything Automation™! (CV Galore!)
- All front panel controls can be automated via sequencer and Remote™, and there is a CV input for all the Harmonic Synthesizer controls, including dedicated LFO inputs to over-ride the internal LFO to the five internal LFO targets
JPS Harmonic Synthesizer is available now in the Propellerhead Store for US $79.