ARP ODYSSEY Mk3 (1978)

The Arp Odyssey 2800 is considered the portable version of the famous modular ARP 2600 designed by Alan Robert Pearlman. This is the "third" model official release from ARP after near ten years of production from 1972 to 1981 with some technical and cosmetic changes.

The "ody" was the the main Minimoog rival- with some strenghts and flaws.

KEYBOARD compact 37 keys synthesizer mainly made out of metal and plastic (weight about 8 Kg) with nice orange-black design.
The main panel features 34 sliders control instead of classical rotary knobs with colored caps indicating the functions area; each synthesis section is particularly clear with a particular logic, directly inspired from the bigger Arp 2600.
>TECH < After many years caps usually crumbles for a faulty production.

On the left side (pic) there are three rubber pads called PPC "Proportional pitch control" a kind of futuristic pitch wheel replacing the classical rotary knob from previous Odyssey models, a Portamento rate slider for legato play and finally a handy three octaves height switch LOW / MID / HI .

Back panel (pic) has the following connections: 1.5mm Control CV / Gate, jack and XLR output, a CV pedal control input (disables some S & H functions) and external audio processing input for filter VCF with line impedance- no gain.

VOICE subtractive analog synthesis with two VCO in monophonic Unison or Duophonic playmode.
VCO1 is always master and has lower priority, while VCO2 has higher and it can set to a special "LOW" mode acting as an AUX Low Frequency Oscillator.
Both oscillators have an independent Volume gain plus a Coarse pitch for wide-fine tuning and special pitch hard-sync mode in VCO2 -> VCO1 way.
VCO1- VCO2 have Sawtooth / Square waveforms with variable Width starting form 50% cycle duty to full Square and extra circuit generates a simple White / Pink Noise that you can mix with the other oscillators, but it has no special control but mix gain.
PWM-VCO1 is modulable by two sources at the same time:

a) LFO Square or Sinusoidal wave
b) S/H or A D S R Envelope.

PWM-VCO2 is a bit different with some variations:

a) LFO sinusoidal or S&H / external pedal
b) Assigned to Envelope ADSR or S&H.

Each oscillators VCO can have pitch modulated by two summable FM modulations: - FM-VOC1: LFO Square or Sinusoidal and/or S&H or Envelope A/D/S/R. - FM-VCO2: LFO just sinusoidal or S&H / external pedal and/or envelope A/D/S/R or S&H.

FILTER analog four poles multimode VCF with resonant LowPass plus a non-resonant simple HighPass. >IHMO< Quite aggressive sound! in fact the "new" filter design seems to be not fat as the previous filter model 4023 "faked Moog" but has its own character and still achieves a very characteristic resonance in auto-oscillation. ENVELOPE two independent EG assignable to Oscillator1-2 FM Pitch and/or VCF FilterA / D and A/ D/ S/ R respectively with with two and four segment stages. The VCA GAIN holds a sound indefinitely likely for drones effects and the REPEAT function retriggers the EG following the Square LFO flow (clocked to the main LFO frequency - but may be synched to external trigger IN) with Latch mode.

LFO a bit weird: one main Low Frequency Oscillator generates three different waveforms Square/ Sinusoidal S&H sharing same frequency (range from 0.2 to 20 Hz); it modulates PWM1-2 / VCO1-2 pitch/ VCF Cutoff.
A second LFO featuring Square / Saw waveform is available interrupting VCO1.
The adjacent "Sample- Hold" mixer is quite unusual for this kind of synthesizer and features two sliders that mix values from VCO1 wave Square (or Saw) and VCO2 wave Square: each sampled step is clocked to LFO frequency or manually retriggered and the generated voltage output has a voltage Slew (smoothing process) called "OUPUT LAG ".

MEMORY none! Just good brain memory or blank sheets: download a free printable version on the right side.

ARP ODYSSEY FAMILY MODELS   "WHITEFACE" model Model: 2800 (from 1972 to 1974) - Rotary Knob bender - No external CV control - 2 poles filter (model 4023) "GOLDEN" model model: 2800->2813 (from 1974 to 1978) -Rotary Knob or late PPC - Later models have CV control (like 2810) - 4 poles "Mooged" (4023) filter replaced by custom 4075 patent infringement.   "BLACK ORANGE " model Model: 2820-> 2823 (from 1978 to 1981) - PPC controller - CV/gate control - 4 poles filter 4075

Classic Chameleon voice Metal lead sample and told bouncy bouncy! Industrial loop Flat Eric Cycler LFO test Modem 56kHz