Intro
You may already know Twisted Electrons as an original electronic musical instruments manufacturer, with excellent products such as the Crazy 8 sequencer and Therapsid. Recently, they decided to take on the Eurorack market with three new modules, inspired by their legacy designs, but also featuring some unique takes on sound creation and sequencing. First, let’s take a look at the AY3, a dual oscillator module.
Vintage sound
The full name of the module is AY3-8912 VINTAGE COMPUTER SYNTHESIZER MODULE which is a pretty accurate description. The AY-3-8912 is a programmable sound generator chip (PSG) designed by General Instrument in the late 1970s. Yamaha licensed the design to produce their sound chip YM2149 with a few form factor changes. The AY3 and its Yamaha counterpart gave a voice to the Amstrad CPC, Atari ST, Intellivision, Apple II Mockingbird sound card, MSX, Vectrex and ZX Spectrum 128K, amongst many early 1980s arcade game consoles that used two AYs – or even more!
The AY3 contains two of these chips as oscillator source, and adds control knobs for spread, arpeggiation and a noise generator. The oscillators share one 0-5v v/oct cv input that controls both pitches at the same time, and the noise generator has its own pitch control input. Similarly, the trigger input drives both oscillators and a separate trigger input controls the noise output. Pitch can also be applied manually via two knobs. The black faceplate seems well-crafted and its design is simple and effective. At 8hp wide, it does not take up too much space in a eurorack cabinet. Although the module needs 5v in addition to the usual +12v and -12v to operate, it can use an on-board power conversion via a jumper on the back if external 5v is not available.
Features
First of all, the sound of the AY3 is quite unique and it has an instant ‘1980s’ feel, especially if you turn up the arpeggiator. Famous videogames from that era are summoned on the spot! The sound is a harsh digital square wave, very different from an analog oscillator. As mentioned, there are two AY3 chips that output at the same time. As there is only one pitch input, the spread knob determines how they are tuned. At 0% only osc1 is active. Above 5%, osc2 is mixed with osc1, and increasing the spread knob drives osc2 pitch up to an octave above osc1. When the knob is turned 80% or more, three chords are available: major, minor and fifth.
This only happens when the arpeggiator knob is used. That knob switches on above 5% and then the arpeggiator alternates between oscillator 1 and 2. As there is no envelope, the trigger input switches the sound on at the output as long as it is active at 5v. The digital noise trigger works in a similar way, creating the possibility to make it sound like a hihat or a snare, or any other percussive effect, depending on pitch. However, there is a jumper on the back that changes the oscillator trigger function to clock the arpeggiator, overriding the speed knob. The noise trigger can also be set to hold using a jumper.
Options
The module actually has three modes: normal, deep or helium which can be chosen on bootup, and is remembered between power cycles. This determines the speed range of the arpeggiator, leading to frantic behaviour in the fastest mode. I had a lot of fun using the AY3, as the sound is so different it is a nice alternative or addition to complex soundscapes, but also does well on its own. I created a complete video game track sequence by controlling the AY3 from a small Korg SQ-1 sequencer, using one channel for the oscillators and the other for the noise.
By changing the pitch and gate length per step a complete drum track can be made with just the noise output. I also found using the oscillator trigger to clock the arpeggiator gives more control and variation which makes the AY3 useful in combination with other clocked sounds. It would have been good if the oscillator spread and arpeggiator speed would have been cv-controllable too, since the module’s sound lacks a bit of variation with regard to pitch and tone options.
Conclusion
Twisted Electrons have succeeded in connecting with their existing philosophy of sound and operation and taken this a step further with the AY3 module. It is a unique sound generator that brings a retro-1980s feel to a modern eurorack setup.
Key features are its gritty ‘video-game’ digital sound, with two oscillators and a noise generator it can form a complete melodic combination to compose with. However, it does not have extensive cv control beyond pitch and trigger. If you are looking for a different oscillator and like 8-bit sounds, give the AY3 a try!
Anything else?
If you’re not into eurorack but want to experience the sound of the AY-3, there is a desktop version with extended control which we will review here shortly!
Price incl/excl: € 179,- ex VAT
More info: twisted-electrons.com/product/ay3-eurorack-module