This is a classic “moog” transistor ladder low pass filter with the usual 4-poles and 24dB cutoff. In 1974 ARP went back to their “moog” filter design (the 4012 module used in the 2600) and updated it to use transistor array chips and put it into the Odyssey as the 4035, and the Pro-Soloist and […]
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This was the first analog synthesizer module I designed back in the Autumn of 2002, after buying a copy of Eagle CAD to design the circuit. It was a prototype for later designs and many lessons were learned… PCB holes too small, no mounting system, ahhgh!! After a few weeks of rework, a production PCB […]
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This is replica of the diode filter in the Roland SH-3 mono synth. The original filter was quite a simple and basic design copied from the EMS VCS3. Roland used a variety of early Op Amps, including the low quality 741 and 1458, and a very old 14-pin dual Op Amp – the NEC UPC33C […]
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This 14HP wide module is a clone of the 24dB Low Pass Filter, fixed High Pass Filter and VCA in the Roland Super JX10. The circuit is based around the Roland IR3R05 chip which first appeared in the MKS80 REV5 replacing the IR3109 and CEM3360, and then made its way into the JX-8P, MKS70, JX-10 […]
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