many years ago i built an analog synth around a doepfer-voicecard with CEM-oscillators and ADSRs. It also had a CEM-LP-filter but this was quite boring. Because i LOVE the formant filter (2x3060 OTAs) i soldered a double formant-filter which could be set parallel or serial. Beautiful sound as you can hear here:

the old z3 sounded cool but lacked a lot of desirable features

the revamped version has some additional features:

• clean interiour
• filters are now independant in mode (LP/BP/HP), Q and F. Can be coupled though with adjustable separation
• built in midi-interface with velocity and 2 control voltages: ModWheel and a learnable Controller
• MS-20-style lfo with waveformtweaking from rising saw over triangle to falling saw or pulsewidth. One-Shot-feature for using as simple envelope or Reset-on-Note or freerun
• third, digital oscillator with multiple waveforms (sid-style PWM) and LFO-mode
• MS20-Ringmodulator
• double-sine-lfo for dense PWM or other modulations
• modulation vca which can be modulated by different sources
• very versatile modulation-possibilities through rotating switches

more updates, sound and videos soon