Unusual Synthesizer Circuits

I built original modular synths when I was a high school student. Rate 1990’s, I joined synth-diy

mailing list and resumed synth DIY. I'm not good at English but I am trying to write most of

the contents in English for the list members who have inspired me.

[WARNING]

This page is not for beginners, but for those who are looking for new synth circuits. Most

of the circuits presented here are not the usual synth circuits. Beginners must become

familiar with ordinary circuits before they can understand these unusual circuits. I will not

answer questions from beginners because my English is not sufficiently good to explain these complicated things to beginners.

The information provided on this website is for non-commercial use only. Some works

may be covered under one or more patents. Contact Osamu Hoshuyama for information

on commercial use.



Original Schematics

Exponential Converter





VCO & Waveshaper





VCF





VCA

EG

Modification





Others





Photos of My Modular

1982-1985 (Dec. 23, 2000. 74 kb) VCO x 2, Noise, VCF, VCA x 2, S&H, ADSR x 2, AR, Gate delay, RM, Mixer, and Piecewise linear function.

1985-2000 (Dec. 23, 2000. 92 kb) VCO x 2, VCF x 4, VCA x 2, ADSR x 2, Spring reverb, Parametric EQ, Digital delay, DNR, Noise gate, ...

2002-2003 (Feb. 01, 2003. 65 kb) MOSular (CMOS Modular Synth in Lunch Boxes.) Midi-CV (Synhouse Midijack ), VCO x 2, VCF, VCA x 2, ADS x 2, AD/AR x 1, LFO x 2, Envelope follower, Inverters, and Headphone Amplifier. All the signal paths are CMOS. Block diagram (41 kb).

2010 (2010) Monodular. (Modularized Monotron) Link to analog-synth.jp



Scanned Schematics

VCF

moritaVCF76.gif (Jan. 30, 2001. 32 kb) Transistor ladder VCF. (LP and HP) Designed by Shin'ya MORITA when he was a high school student.

moritaVCF77.gif (Jan. 30, 2001. 31 kb) Transistor ladder VCF designed by Shin'ya MORITA in 1977.

moritaVCF783.gif (Jan. 30, 2001. 29 kb) Diode bridge type 2 pole VCF designed by Shin'ya MORITA. Untested.

moritaVCF785.gif (Jan. 30, 2001. 48 kb) Diode bridge type 4 pole VCF designed by Shin'ya MORITA. Untested.

moritaVCF786.gif (Jan. 30, 2001. 23 kb) Re-invention of Moog-Musonics Sonic-V style VCF by Shin'ya MORITA. Tested on breadboard.

EG

moritaEG78.gif (Jan. 30, 2001. 42 kb) Simple ADSR designed by Shin'ya MORITA. 1978. Untested.

gx1eg.gif (Jan. 30, 2001. 19 kb) VC ADSR of Yamaha GX1. Redrawn by Shin'ya MORITA.

KB

moritaKB.gif (Jan. 30, 2001. 34 kb) Dual voice KB designed by Shin'ya MORITA. 1977 or 78.







Circuit Analysis and Links to Interesting Schematics (in Japanese)

Mail to Osamu Hoshuyama