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The Akai Ax-80

The AX80 has the privilege of being the first pro-keyboard produced by Akai, released in 1984. It's an eight-voice programmable analog synthesizer with a full 61-note keyboard and a series of techno-looking LCD bar-graph displays running across the top of the keyboard. Two analog oscillators per voice plus a sub oscillator provide the basis of its punchy analog sounds that can be described as similar to a Chroma Polaris or Roland Juno 106. Very good bass, brass, synth sounds, and effects are possible. However its strings are average at best.

The blue and orange florescent LCD displays use a simple and intuitive bar-graph format to show all its parameters and values, making for one of the best on-board displays ever! You have to wonder, however, with such a cool display, why couldn't they have included dedicated sliders and knobs for each parameter (see the AX60). A decent amount of patch storage and nice enough sounds make the AX80 a useable synth to have around, but it probably won't replace your Roland Juno. Other notable features of the AX80 include an angled rear panel for easy cable connections, chord memory, MIDI control, and pitch/mod wheels.

The AX80 is a polyphonic analogue keyboard synthesizer manufactured by Akai Professional in 1984. It was Akai's first venture into the professional electronic musical instrument market. The AX80 used digitally controlled oscillators (DCO) and filter circuitry based on the Curtis Electronics CEM 3372 integrated circuit. It was marketed as part of a line of project studio equipment called the Akai Music Studio System, which included the S612 digital sampler the MR16 drum machine, the MS08 sequencer, and the MG1212 multi track tape recorder, at a price of $1,695 US.

This electronic keyboard is an 8-voice polyphonic, digitally controlled analogue synthesizer. It has 64 memory locations for sounds ("patches"), arranged in two banks of 32 each, plus a bank of 32 factory preset sounds. The instrument has basic MIDI implementation, but lacks the ability to save or restore sounds except by using cassette tape.

The front panel has a volume knob, a master tuning knob, a data entry knob for programming patches, modulation and pitch wheels with knobs for the depth of the effect, and various buttons to switch on and off modulation destinations, enable chord memory, transpose the keyboard, or infinitely sustain notes. The case is black metal with fluorescent displays to indicate the status of different synthesis parameters, and black rubberized end pieces.

The back panel is unusual in that it is tilted from vertical so that the connectors can be seen from the front of the instrument. There are quarter-inch jacks for recording data to cassette tape, sustain and program change footpedal jacks, MIDI in, out and "thru" DIN connectors, a monaural quarter-inch audio output, a quarter-inch headphone jack, and memory protect and power switches.

The keyboard is five octaves (61 notes, C to C) and is unweighted. It has velocity, but not after touch, sensitivity. The output MIDI velocity values span the full range (up to 127), but only discrete "steps" are used (in other words, not every integer value from 1 to 127).

The synthesizer voices are somewhat similar to those found in the Roland JX-3P or Teisco SX-240, in that there are two oscillators (referred to as "OSC"s) per voice, with the option of saw tooth and/or square wave forms. These oscillators are controlled digitally with analog circuitry used only to create the saw tooth wave shape.

OSC2 can be synchronized to OSC1, or the two oscillators can be cross-modulated. The OSCs can be separated by semitone intervals (up to four octaves) and detuned (to approximately a semitone). There is pulse-width modulation of the square wave of OSC1 (with a dedicated low-frequency oscillator (LFO) for this) and a square-wave sub-oscillator that is fixed at one octave lower. OSC2's pitch can be modulated by one of the two ADSR envelope generators, which are dedicated to VCA volume and VCF cutoff frequency. The filter is a 24dB/octave (four-pole) resonant low pass type, and there is also a separate 12 dB/octave high pass filter that is not envelope controlled.

Tracking of filter cutoff frequency with keyboard position is fully variable, allowing for sounds to become either "brighter" or "darker" as higher notes are played. Keyboard velocity can affect volume and/or filter cutoff.
The modulation section of this synthesizer features four low-frequency oscillators. Three of these each have four available wave forms (sine, square, saw tooth and ramp), and these LFOs are dedicated to filter cutoff, and pitch of each of the two oscillators. These also have a programmable delay before their effect sets in. The fourth LFO is dedicated to pulse-width modulation of OSC1, and only its rate and depth are programmable.
There is also a programmable output level for each patch, to help balance loud and soft sounds. Notably missing from the voice architecture are white noise and portamento.

The AX80 has knobs for master volume and tuning, and a data entry knob that can be used to alter the currently selected parameter in real-time, although the value will jump to the knob's current position. There are various switches to select modulation destinations controlled by the modulation wheel (filter and pitch), to enable chord memory or infinite sustain of notes, and to select or edit sounds. The pitch-bend and modulation wheels also have knobs governing the depth of the effect of each. Foot switches can control sustain or switch sounds by moving up one patch at a time.

The AX80 has fairly standard MIDI implementation for an instrument of this vintage, with the ability to use any channel (1-16) for transmission or reception (these can be set separately). The instrument does not recognize the MIDI tuning request, nor does it allow for saving or loading sounds (patches) to a computer via system-exclusive data dumps.

Polyphony - 8 voices
Oscillators - 2 per voice + Sub Osc. (sawtooth or variable pulse width)
Filter - 8 VCFs (1 per voice)
VCA - 8 ADSRs (1 per voice)
LFO - 3 LFOs controlling OSC 1, OSC 2, VCF
Keyboard - 61 keys (velocity sensitive)
Memory - 96 patches (64 user, 32 preset)
Control - MIDI
Date Produced - 1984

It's been used by Mark Bell (LFO) on Bjork's Homogenic and various other artists.