Altair 231 is an almost identical copy of the famous Moog Minimoog, made in the former Soviet Union. Biggest difference in sound is caused by different brand of components: soviet equivalents are used everywhere.

The oscillator board is based on the older version. However, the soviets  were clever and used multi-turn potentiometers for the scaling controls. Result: Synth stays in tune better. The soviets didn't seem to have reverse log pots. Because of that, the resonance control was wired backwards and a regular logarithmic pot was used instead. Other than that, the synth seems to be very robust and easy to service - the real Mini schematics come for good help when comparing the component numbers etc. It sounds like a Mini! I heard a Mini with the newer oscillator board and I think that's the reason for minor differences in sound between it and the Altair.

It is a monophonic 3 OSC analog synthesizer. Synth has 4-oct keyboard (F-C) with velocity (sensitivity assign to vibrato effect). The synthesizer has based on 3 VCO (osc. No.3 can work as the modulator), 1 VCF (lowpass 24dB/oct)with ADSR, 1 VCA, 3 LFO, noise generator (white/pink), portamento, memoryloop. It has an EXTERNAL INPUT allowing to use FILTER and GENERATORS with external audio INPUT.

OSCILLATORS section: - osc 1,2,3 registers - 2", 4", 8", 16", 32", LF - osc 1,2,3 waveshape select - triangle, saw, square, pulse, sine - osc frequency - freq 1..3, freq 2, freq 3 -linked to keyboard pitch on/off (osc 3 ONLY) MIXER: - osc 1,2,3 on/off, level - ext input level, on/off - noise generator level, on/off - noise mode switch: white/pink MOD section: - portamento on/off, rate; - mod mixer knob: balance between modulated by OSC3 and noise, depth amount; - pitch wheel (glissando)

FILTER: - mod on/off - cutoff, resonance, brightness - attack, decay, sustain - keytrack on/off

AMPLIFIER: - attack, decay, sustain - key hold memory on/off Next - global section: main volume, phones volume, phones out (5din), A-440Hz tone on/off, power. Connections :

Audio OUTPUT, Audio INPUT on standard 1/4''jack, pedal input on 5-Din socket , power wire connection (220/240V), fuse (0,5A) .

Architecture

Type: Analog

Synthesis: Subtractive

Oscillators

Oscillators: 3

Waveforms: Pink Noise, Pulse, Saw Up, Sine, Square, Triangle, White Noise

Osc Modulation: Envelope, Glide / Portamento, Keyboard, Knob, LFO, Mod Wheel, Pitch Wheel

Envelopes

Envelopes: 2

Evelope Paramerters: Attack, Decay, Sustain

Filters

Filters: 1

Types: 24dB Slope (4-pole), Low Pass, Resonance

Filter Modulation: Envelope, Keyboard, Knob, LFO

LFO

LFO: 1

LFO Parameters: Noise, Saw Down, Sine, Square, Triangle

Polyphony & Tuning

Polyphony: 1

Timbrality: 1

Tuning: Standard

Modes: Mono

Case

Case: Keyboard

Keyboard: 49 keys

Controls: Knobs, Switches, Mod - Wheel, Pitch -Wheel

Connections

Audio Output Connections: 1/4" Phone Jack, Mono Out

Inputs: 1/4" audio input

Power: 220V AC

Contact me with any questions!!!