ESC
Quadra

Quadra

BrandArp*
FunctionSynthesizer
Produced1978-1981
CountryUSA
Form FactorKeyboard
Signal PathAnalog Hardware
Power200 to 250 Volts, 50 to 60 Hz, 20 Watts, IEC Socket
Frequency Response16Hz to 16Khz
Channels1 Voice
LinksSound on Sound Review
NotesThe ARP Quadra was a 61 key analog musical synthesizer produced by ARP Instruments, Inc. from 1978 to 1981. The machine combined pre-existing products: the Omni, Odyssey, a Solina-esque string unit, a phase shifter and a divide-down organ with ADSR, and a 4075 24 db low pass filter into one box. It has four sections. Bass is on the bottom two octaves, has two unison bass circuits (electric and string), with AR and a single pole low pass filter and a related AD envelope for cutoff. A string section is similar to the ARP Omni. Poly Synth, and a two voice Lead Synth similar to the Odyssey and a five way mixer with four unit outputs, a stereo pair, a line mono and an XLR out. Polyphony 1 (Bass), 2 (Lead), All (String, Polysynth) Timbrality 4 Oscillator 4 (2/Lead, 1/Poly+String, 1/Bass) LFO Triangle, Square Synthesis type Analog Subtractive Attenuator Decay (Bass), AR (String), ADSR (Poly), ADSASR (Lead) Memory Panel Switch state, Octave, Osc. Interval Effects 1 (Stereo Phase Shifter) Input/output Keyboard 61-key synth-action with Channel Aftertouch (Lead only) Left-hand control Portamento VCO1, Portamento VCO2 External control CV/Gate