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AM1182 - 8x2 Analog Sequencer
Cloning the Roland M-182
Introduction
Between 1978 and 1985 Roland manufactured an entry level analog modular synthesizer called the System 100M. It provided a nice range of modules packed into a small size. The construction and sound quality were very good and second hand examples are now sought after and change hands at £1500+.
The VCO's and filter use hard to find parts such as the ua726 dual transistor and the Roland specific BA662. The 8x2 Analog Sequencer module is a very simple but effective design, based on readily available CMOS chips. It can be
easily cloned. It is hardly an original idea or design, but it's a quick way of getting a basic 8 step sequencer.
Original Circuit
The M-182 has 2 sets of 8 control voltage steps, which can be run in series or parallel. There is an internal clock with Tempo and Gate Time, Tempo has voltage control. The sequencer can be manually stepped, and sequences can be single shot or repeated. There are two Control Voltages, which are not quantised.
Original Specifications:
- Tempo: variable from 0.14Hz to 33Hz
- Gate Time: variable from 10 - 90%
- Portamento: variable from 0 - 10 seconds
- CV Outs: 0.3 to 10 Volts, 2 ranges
- A LED for each of the eight steps
- Trigger In and Gate Out
- End Pulse Out
- Tempo CV In
- CV1 and CV2 Out
AM Circuit The Analog Metropolis Model 1182 replicates the Roland M-182
circuit exactly. It is built on 2 new PCB's that mount to a standard 4U 135mm wide Analog Metropolis panel. The following changes to the original design have been made:
- 5mm Blue (or any other colour!) LED's
- Minature slide switches
- ARP 2500 knobs for the smaller pots
- MIDI clock interface (Blacet MIDI Sync IC)
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Site Options
Resources
* Roland M-182 Schematics 
* AM Model 182 Schematics 
* Front Panel .fpd file