Altair Estradin - 231 [MiniMoog] | Альтаир Эстрадин-231, 1986, made un USSR

Link: ruskeys

Monophonic synthesizer Altaiir 231 (Estradin factory, Zhitomir city) is intended to play different sounds from the imitation of natural instruments to complicated synthesized electronic timbres, sound effects, percussion sounds & so on. There are a four-octave keyboard & a wheel to pitch control. There are also controls for parameters on the front panel, an output for phones, an input for a pedal. The instrument consists of four main blocks of sound synthesis - Generator, Mixer, Filter and Contour.

Synthesis is based on 3 master oscillators (each of them with different parameters of registers) waveform, frequency modulation. There is also a generator of white & pink noise. Low-pass filter with main parameters gives the possibility for keyboard tracking. Portamento adjustment knob is provided. To tune a pitch the tone signal is used (440Hz) It provides a linear input to connct an external sound source to Altair. Output and input sockets are 1/4" jacks

ALTAIR-231 is a Soviet Minimoog equivalent. If you are familiar with Soviet synths you might know that ESTRADIN-230 has absolutely identical schematics (all 6 PCBs) with ALTAIR-231.

ALTAIR-231 is powerful monophonic 3-OSC synthesizer produced by Elektroizmeritel, millitary radio plant in Zhitomir, USSR, 1986. Synth has 4-octave keyboard (F-C) with velocity (sensitivity assign to vibrato effect). For live performance there is a wheel which provides pitch shift. ALTAIR-231 is based on 3-VCO (OSC-3 can work as the modulator), 1 VCF (lowpass 24dB/oct) with ADSR, 1 VCA, 3 LFO, noise generator (white/pink), glide, memory. It has an EXTERNAL INPUT allowing to use FILTER and GENERATORS with OTHER INSTRUMENTS such as guitars, synths, etc! ALTAIR-231 consists of 5 main sections - OSC, MIXER, MODULATION, FILTER and AMP.

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 as MAIN OSC)

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

global section: main volume, phones volume, phones, A-440Hz tone on/off, power.
Connections: input, output, pedal input, phones.
Power supply: 220V/50Hz, 127V; fuze 0,125A

Dimensions (mm) 754x466x110 (29.6"x18.3"x4.3")
Weight: ~ 18 kg (39.68 pounds)