via this auction
"Built 1978
Type: analog
1 Voice / Stimmen
1x Multitimbral
Synthesis: subtractive
OSC Features hard sync ringmod filter FM mixOSC
Wave Shapes pulse saw triangle noise white pink
2 OSCs + 5 SubOSCs
2 Filter lpf hpf bpf self reso + static hpf 4 Pole
1 LFOs square saw sine
3 Envelope Generators 2x ADSR 1x D
CV GATE Control / Triggering
36 Keys"
The 5 SubOSCs are the additive part. If you look at the top right of the oscillator section you will see five sliders, one for each waveform.