Oberheim 4-voice (1975) – it’s kind of a poly and kind of not. It’s a very weird (and great-sounding) system that can totally change the way one thinks about composition.
Using it as a poly is not difficult. Just set all the SEM controls to the left (counterclockwise) and use the programmer to dial in a basic patch and supply VCF/VCA envelopes; about half the controls are non-programmable (filter type/resonance/PWM etc.) but the ones requiring exact adjustment (pitches, filter cutoff, envelope times) are. Non-programmable controls like PWM depth generally have more “tolerance” in that they can be a little off between SEM’s and it’s hard to tell the difference. So, not as bad as it seems. Above all you don’t need to adjust each control on each SEM!
The fun really begins when you make offset adjustments on the individual voices. For instance, the second and fourth voices can transposed by an octave, or have a different timbre, this can lead to a lot of novel sequencing. A lot of playing with “streaming” phenomena, for lack of a better word. There are two outputs, which I use independently (not as stereo pair), each voice goes to one or the other. it’s common that I delay one, also then there’s a global filter cutoff pedal (the programmer can also be used)
with custom CV/gate ins, I also use as a kind of mono or dual synth, playing 2 voices in unison, one for each output, then delaying or effecting one. Sometimes then layering one voice with another voice. Here I can make the filter cutoff track by routing the same CV to each voice and the pedal. Another way to explore new compositional ideas I wouldn’t have arrived at on my own.
Anyway, I find instruments around this time much more interesting, people didn’t know quite what a polysynth was supposed to be (Korg PS-series also fits in this category) though I’ve never played them, so designers created these wonderfully weird environments that lead to new types of composition before the late 1970’s where things became boring and standardized.
I find not being interested in other polys, actually. Except for PPG 360… but I can never find one and once I did, was too scared that it would be destroyed in international shipping.
Also – learned the hard way that modern SEM do NOT sound the same. in the new SEM the oscillators are surprisingly thick but the filter is lacking quite a bit. Very clinical in the new one. It’s a components issue; apparently the circuit designs are the same… that is what is depressing that there even is this lost magic in the old components and manufacturing processes forgotten because they were “obsolete”. The ruby glass…
