Synthesizer Schematics Download Section :

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All circuits are for personal use only

© Marjan Systems/Marjan Urekar 1999.-2001.  All rights reserved.

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 01. EML-101 Multimode VCF                         Familiar SEM style State Variable Filter LP/BP/HP
                                                                         with discrete components instead OTAs.

 02. SERGE Triple Waveshaper Module         Triple WS and one part of Serge Waveform Multiplier
                                                                         use this scheme, just one opamp from LM3900,
                                                                         it takes saw VCO input and rectify it to triangle/sine
                                                                         output, but can also be timbre modulator for any signal.

 03. BUCHLA #194 Fixed Bandpass Filter     Not very exotic module, but it might come handy.
                                                                         Splits input signal into four bands 200/200-900/
                                                                         900-4000/4000 Hz, using just few transistors.

 04. KORG Polysix Ensemble LFO                  Dual fixed three phase LFO used for modulating triple
                                                                         BBD delay lines in Ensemble effects. Uses single CD4069
                                                                         and has CV control of Intensity (amplitude).

 05. MINIMOOG VCA                                      Simple discrete VCA with 9 transistors. Crucial part of the
                                                                         Mini's sound, together with it's VCOs, VCF and fast EGs.

 06. BUCHLA #291 Dual Bandpass VCF        VCBPF with Vactrols and lots of control/process power.
                                                                         VC center freq (30Hz-15kHz) with offset, VC bandwidth
                                                                         (1 semitone-4 octaves) with offset, resonance, FM,
                                                                         input level, could be trimmed for selfosc.
                                                                         Low noise and high dynamic range.

 07. SERGE Sequential Pulse Source             10-step gate/trigger sequencer with CD4017. (updated)

 08. OBERHEIM Matrix-6 White Noise           Simple but nice sounding noise generator from polysynth.

 09. R0LAND  D-Beam                                    IR Light Controller with CV (thanks to D.F.) (partial schem)

 10. KORG MS-20 LFO                                   Superb LFO with waveshape and range controls.
                                                                         UpSaw/Triangle/DownSaw and Pulse waveforms.  (updated)

 11. SERGE Lin/Log VCA                               Standard CA3080 based design.  (updated)

 12. ROLAND SH-09 Noise and S/H             My favourite! Simple transistor white/pink noise generator
                                                                         and S/H with two FETs. Add it to your boring LFO section!

 13. EMS VCS3 Type Ring Modulator            Neat RM based on famous VCS Synthi. Very low parts count,
                                                                        but distinctive sound. Looks like discrete MC1496 chip!

 14. MOOG Source VC LFO                           Modification of standard tri/square LFO, with additional VCA.
                                                                        VC and manual controls of speed and level parameters.

 15. SERGE Ring Modulator                           OTA design, based on VCA, reliable stuff.  (updated)

 16. EML  101 Schematics                            Scans of (in)famous EML 101 schematics. Expo convertors, Oscillators
                                                                       1,2 & 3 and VCF are here. Interesting "lo-end" approach.
                                                                       Contact me if you have the rest of the schematics for this beast.

 17. ROLAND/KORG Transistor VCA            Based on Roland JX-3P and Korg MS10/20/Polysix  VCAs.
                                                                       Transistor and opamp, simple, noisy, strange, but works after all!


 Marjan Systems and ForceMajeure
by Marjan Urekar