Send In The Clones: AMSynths Diode-01

US A System 100 clone of great potential!      13/12/23

Classic synths are coveted for a number of reasons. Whether it be for their warm (or charmingly naive) vintage sound, beautiful aesthetics or unique workflows, the old adage applies; "They don't make 'em like they used to!"...

...Or maybe they do? ln this series of articles, we'll cover attempts to re-make classic synths in the here and now. Will they live up to the original instruments or perhaps even improve on them? Read on, dear viewer...

AMSynths is a synthesizer manufacturing company led by Rob Keeble in West Sussex, UK. Rob is a former IT professional, now electrical engineer & electronic musician; certainly a good skillset for building synths! His first attempt (like many tinkerers) was 1974's "Minisonic 2" as featured in Practical Electronics Magazine, a garishly brilliant stylus-controlled synth complete with ladder filter, ring modulator and zero hope of playing in tune!

Since 2011, AMSynths have specialised in analogue eurorack modules, creating a large range of oscillators, amplifiers, filters and modulators based on classic designs from ARP, Curtis, Moog & Roland, with some playful tweaks. (For instance, their CEM3328-based filter goes into self oscillation, try that on an original Ensoniq Mirage!) And now they are turning their attention to the Roland System 100 semi-modular synthesizer.

I'm not really an analogue monosynth fanatic. I enjoy my Mono/Poly's quirks (secret LFO-tricks etc) and running external audio through my Minibrute SE, but most of my analogue enjoyment comes from either early 80's Polysynths (which scored the cartoons of my childhood) or hybrid digital/analogue approaches.

However, the moment I laid eyes on the System 100, I knew it was something special. Brian Duffy of the Modified Toy Orchestra owns a beautiful & complete example (above), consisting of:

• Model 101 (VCO/VCF/VCA/ADSR)
• Expander 102 (as 101 minus keyboard, but adds ringmod & S/H)
• Mixer 103 (with spring reverb!)
• Sequencer 104 (2x12 Steps)
• Monitor Speaker 109

 

Noodling around on the imposing instrument (in terms of size & sound!) is a joy. Anything is possible, from delicate leads through drippy spring to thunderous basses and unholy clangs, via a whole cityscape of futuristic timbres. AMSynths are clearly a fan too, as they've been thinking about cloning the machine for some time:

The idea of making a replica of the infamous Roland System 100...was born in Boston USA in 2018. The inspiration is from the first Human League records which I listened to after returning to the UK in 1980. Once I had secured a job as a Network Engineer in Luton I was able to buy a few records; Travelogue, Emotional Rescue, Double Fantasy, Scary Monsters. Very different styles of music, with the most radical being the Roland System 100 drum sounds by Martyn Ware.

The DIODE-01 is a replica of the 101 and 102 synthesizers that were introduced at the start of 1976, selling over 4000 units over the next 3 years. The 101 was £795, and the 102 a little bit cheaper, which is equivalent to over £5,000 today, but half the price of a Minimoog! I have blended both synths together into one 60 HP module, with almost every feature retained. The keyboard has been left out, along with portamento and the S&H lag facility. No headphone amplifier or A440 reference tone either. BUT everything else is on board and replicated exactly, to deliver the same raw analog sound, the DIODE -01.

It's worth noting a couple of things about this exciting instrument. You're not quite getting a whole Model 101 & Expander 102, there's only one VCO after all, but you are getting a lovingly replicated signal path "with a switch to modern components and replacement of  obsolete components" where required. Engineering types can read the gory details here:

https://amsynths.co.uk/home/products/diode-01-a-system-100-clone/

It's also worth bearing mind that the attractive (provisional) £399 price doesn't include a case:

The DIODE-01 comes as a 60HP panel with no case. It does fit (a standard) Moog powered 60HP case. I use unpowered Moog cases with my own internal power supply for the demo system (3 tiers of DIODE-01). The synth has two PCB's with a depth of around 35mm. There will be a SMD kit version where the customers adds switches and pots and the PCB's come with all the SMD components soldered on. A basic THD kit might be made available.

Full features:

The DIODE-01 maintains the unusual layout of the original design with the modulation sources on the left including the envelope generator. The synth is semi-modular and the normailsed patching is illustrated by blue lines (CV signals) and orange lines (audio signals).

• Envelope Generator - traditional but fast ADSR
• LFO - with three waveforms (triangle, sine, sawtooth)
• S&H - with its own wide ranging clock (0.25Hz to 400Hz)
• VCO - with range switch and four waveforms (triangle, sawtooth, square, pulse)
• The VCO has the sync feature of the 102 (strong or weak)
• Noise source with white and pink colours
• Ring Modulator, normalised to the VCO and LFO
• High pass filter, 3dB passive design
• Voltage controlled 24dB diode filter with self oscillation
• Voltage controlled amplifier

 

There's room for innovation upon the original's connectivity too, a VCA CV IN is available on the top right to enable external envelope control of the VCA. Production units are expected to arrive around February 2024 and they will have a dark grey powder coated panel with three colour silk screen print.

Diode-01 Page at the AMSynths Store

Thanks for checking this article out, there's plenty of interesting clones coming out at the moment, from both larger and smaller makers, so let us know in the comments what you'd like to see featured in this ongoing series!

Posted by MagicalSynthAdventure an expert in synthesis technology from last Century and Amiga enthusiast.

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