The SYNTH PRO is the advanced, polyphonic version of the SYNTH II. All oscillators are discretely structured. So here are for the sound base so no highly integrated chips are used, but proven components that even in Synthesizer 40 years ago produced a great analog sound. If required, the VCOs can be switched over to the particularly stable DCO mode, for example if unfavorable environmental conditions have to be overcome. The provided waveforms can be superimposed and additionally modulated by different sources. VCO2 and VCO3 can be synchronized to the first oscillator. For this purpose, VCO1 and VCO2 can be frequency-modulated with VCO3. In the SYNTH PRO, two filters are used per voice, which can be connected in series or in parallel. The low-pass filter works as a cascade filter with a slope of 24 dB / oct. and uses the popular SSI 2144. Multifilter and VCAs are based on OTA's. Both filters and the VCA's can be modulated by different sources. The LFOs and envelopes are calculated per voice by fast processor. There is also a dedicated chip for the effects section. This can produce not only reverb and echo but also chorus and flanging effects. The built-in sequencer works polyphonically and is available in addition to a monophonic arpeggiator.