Like the original, the new Prophet-5 and Prophet-10 modules feature two multi-waveform analog oscillators, analog resonant low-pass filters and amplifiers, and a filter and amplifier envelope per voice. Modulation is provided by a multi-waveshape LFO and Poly Mod, a ground-breaking modulation scheme for its time that allowed the filter envelope and oscillator B to be routed to a variety of destinations including filter cutoff frequency, oscillator A frequency, and oscillator A pulse width. And just like the new Prophet-5/10 Rev 4 keyboards, the modules feature genuine Curtis VCOs and filters as used in the Prophet-5 Rev 3, as well as the Dave Rossum-designed SSI 2140 filter — the modern counterpart of the original SSM 2040 Rossum designed in the Prophet-5 Rev 1 and Rev 2. A Rev switch on the front panel allows users to switch between the two as desired. Also present is the new Vintage knob, which loosens up the oscillators, filters, and envelopes from voice to voice as they typically are in vintage Prophet-5s. Users can dial in progressively more vintage character from a very stable “4,” as in Prophet-5 Rev4, all the way to “1,” as in Prophet-5 Rev1, which was the most temperamental of all Prophet-5s. The original factory sound set is included as well. Other modern enhancements include velocity sensitivity and aftertouch to increase expressiveness, as well as MIDI and USB connectivity. Control voltage and gate ins/outs are also present for connecting modular synths and other gear. The new modules are housed in a premium-quality, steel case with hand-oiled sustainable black walnut heartwood trim.