|This article does not cite any references or sources. (July 2009)|
|Manufactured by||ARP Instruments, Inc.|
|Dates||1972 - 1981|
|LFO||Sine, Square, S&H|
|Synthesis type||Analog Subtractive|
The ARP Odyssey was an analog synthesizer introduced in 1972. Responding to pressure from Moog Music to create a portable, affordable (the Minimoog was US$1,495 upon release) "performance" synthesizer, ARP scaled down its popular 2600 synthesizer and created the Odyssey, which became the best-selling synthesizer they made.
The Odyssey is a two-oscillator analog synth, and was one of the first synthesizers with duophonic capabilities (the ability to play two notes at the same time). One potential appeal of the Odyssey is the fact that all parameters, including a resonant low-pass filter, a non-resonant high-pass filter, ADSR and AR envelopes, triangle (not sine) and square wave LFO, and a sample-and-hold function are editable with sliders and buttons on the front panel.
There were many versions of the Odyssey over the years.
ARP Odyssey models 
Odyssey Mk I (Model 2800) 
- Produced between 1972 and 1975.
These original white-faced Odysseys used a 2-pole VCF filter design similar to old Oberheim SEM modules.
- Later Mark Is were made with the black and gold color scheme, and some may also have the CV/Gate/Trigger interface jacks installed (ARP mod kit #6800101).
These earlier units contained a greater number of internal adjustments and were slightly more difficult to calibrate.
Odyssey Mk II (Model 2810-5) 
- Produced between 1975 and 1978.
- The Odysseys I and II look and feel virtually the same. The main difference between them are the addition of CV/Gate control and a new black and gold color scheme. The 2810 introduced a beefier 4-pole VCF. This filter was similar to the Moog filter and did not last. A persistent rumor has it that Moog sued ARP over this, but no suit ever occurred. Arp and Moog came to an amicable agreement and a small licensing fee was paid by ARP for units previously manufactured. ARP soon after designed their own four-pole, low-pass filters. They came up with the 4075 filter which was used in subsequent Odyssey models. The similar 4072 was featured in the 2600, Omni, Axxe, Solus, and others.
Odyssey Mk III (Model 2820-2823) 
- Produced from 1978 to 1981.
- The Mk III featured the new 4075 filter design. The rest of its specifications are virtually identical to the Odyssey II except that the overall look and quality are further updated to match the look of the latest ARP synths with the orange and black "Halloween" color scheme. It also used a unique ARP pitch-bender design called the PPC (Proportional Pitch Control), where three pressure-sensitive buttons are used to control bend up, down, and vibrato; older Odysseys used a simple knob for pitch bending. The Odyssey Mk III is the most common Odyssey model.
- Mk III Odysseys have XLR outputs, in addition to unbalanced 1/4" outputs.
- Switchable between sawtooth, square, and pulse waveforms with oscillator sync, a ring modulator, and pink or white noise.
- Pulse-width can be modulated manually or with the LFO or the ADSR envelope generator. There is a (static) high-pass filter, as well as a voltage controlled low-pass self-oscillating filter.
- The filter can be controlled by either of the two envelope generators, an ADSR (attack, decay, sustain, release) and a simple AR (attack, release) and modulated by the LFO, sample-and-hold, the keyboard, or a separate CV (pedal) input on the back panel.
- The Sample/Hold input mixer can be used to route the output of the VCOs to the FM input of VCO 2 and the VCF, enabling audio frequency FM.