AY-3

AY-3

The AY-3-8912 is a programmable sound generator (PSG) designed by General Instrument at the end of the 1970s.
The AY3 gave voice to the Amstrad CPC, Atari ST, Intellivision, AppleII Mockingbird sound card, MSX, Vectrex, ZX Spectrum 128K. Many early 1980s Arcade Games used two AYs; the Gyruss arcade board had five!

The AY3 eurorack module is the perfect solution to capture this piece of history in your rack with its slick & sturdy all-metal design and intuitive controls. The module can be set to 3 clocking modes: normal, helium (overclocked) and deep (underclocked), pushing the range of frequencies and sounds to the extreme.

The AY chip brings with it a whole range of strict limitations which were embraced resulting in some highly unique forms of sound and music.

Operation Overview:
Osc 1+2:
Osc 1 & 2 are detuneable and can be switched or arpeggiated.
Use the tune knob to tune both oscillators within 1 octave range.

The spread knob will increase osc2 pitch up to an octave above osc1.
Chords: Turn the spread knob above 80% for 3 chords:
Major, Minor, fifth. Only active when Arp is running!

With Arp Knob at 0% both oscillators play simultaneously. Above 5% osc1 and osc2 alternate for arpeggiator effects. (0.5Hz to 125Hz).

Gate effect: When arp is above 5% and only osc1 is active (spread knob below 5%) osc1 will toggle on & off resulting in a gate effect.

The trig input has two modes (selectable via a jumper at rear):
Gate Mode: send a 5V pulse to turn Osc 1 & 2 on or off (5V=On 0V=off).
Arp Mode: send a 5V pulse to clock the switch/arp (overriding the arp knob).

Noise:
Osc 3 outputs digital noise for sound effects.
The pitch can also be modulated via the pitch jack (0-5v)
The Osc3 gate can be opened and closed via the trig input (5v pulse) or held open via a jumper.

You can select to either source the 5V internally or externally to save current on your 12v rail

5V external mode:
5V: 74mA
12V: 7mA
-12V: 7mA

5V internal mode:
12V: 80mA
-12V: 7mA

http://twisted-electrons.com/ay3-eurorack-module/