Roland System 100 Model 101 SN 511080

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Published on Nov 5, 2013 Tim Churches·2 videos

"Demonstration of the operational status of a Roland System 100 Model 101 monophonic synthesiser offered for sale in as-is condition to Australian buyers on eBay in November 2013."

via this auction

Pics of the inside below.

"An unmodified Roland System 100 Model 101 monophonic synthesiser in rough but mostly working condition. Manufactured around 1975, bought second-hand in about 1982, and then stored in a somewhat damp garden shed ever since. Internal 240V power supply with original Australian plug.

The cosmetic condition of the unit is poor, but it still works. For a 10 minute video made on 5th Nov 2013 demonstrating it working, see http://youtu.be/cFs5J9u_l64

Please examine the photos on this listing carefully, and note the following points carefully:
completely original condition, no modifications or additions
there is a lot of rust on the exterior, including rust under the enamel of sections of the control panel, and on all other exterior metal surfaces
inside there is much less rust, just a few small patches at the rear of the case
all the circuit boards, circuit components and wiring look fine, no obvious corrosion or degradation given that it is nearly 40 years old (see photos of PCBs)
several of the keys on the keyboard do not work - the top key doesn't trigger at all, and a few of the keys trigger the gate unreliably - the contacts probably just need cleaning
all the keys on the keyboard are intact and undamaged, and mechanically all the keys seem to work fine i.e. no broken springs or hinges
all the panel sliders (potentiometers) seem to work, although most of them are a bit stiff, and a few (filter resonance, LFO speed and portamento) seem to be a bit electrically noisy and/or jittery
all the panel rotary potentiometers work fine, although the main VCO frequency pot is very stiff (but not electrically noisy)
the VCO waveform selector switch is a bit unreliable when selecting the sawtooth waveform - it needs a wiggle to make it work sometimes
the high and low level main output sockets and the headphone socket (all of then 6.5mm) all work correctly
the 3.5mm socket modular jack points and the CV and gate input and output sockets (3.5mm) on the rear have not been tested but there is no reason to think they would not work (at worst the socket contact points may need a clean)
all sections of the synth circuitry appear to work correctly and reliably, subject to noisiness and jitter in some of the control pots noted above (see video on YouTube demonstrating this at http://youtu.be/cFs5J9u_l64 )
no manuals or documentation, but a full set of user manuals, patch cards, and the technical service manual are available at http://fa.utfs.org/diy/roland100/
series of photos showing how to service the control sliders can be found at http://fa.utfs.org/diy/roland100/system100_restoring/
the synth probably needs re-calibration, but all the trimpots are very readily accessible on the circuit boards (see photos) and calibration instructions can be found in the service manuals.
please do not open the lid on this synth unless it is switched off and unplugged from all mains power! The mains wiring inside is original, and reflects safety standards from 40 years ago. However, both the mains and DC sides of the power supply are fully protected by fuses. Nonetheless, use of a residual current detection (RCD) power safety device when using this synth is strongly recommended.
Overall, this synth looks rough but it mostly works, and could easily be restored to perfect working condition (although cosmetically it will never look very good). Due to the many patch points which use 3.5mm jacks, the 10V p-p signal and CV ranges, and the 1V/oct CV tracking (with external CV and gate in and out jacks), it should integrate easily with modern Eurorack module synths for someone who wanted the classic Roland modular synth sound. Alternatively, it could be a donor for spare parts to keep other System 100 Model 100s (or System 100 Model 102 expander modules, which use mostly identical circuit boards) operational."