ARP Avatar, with the included hex pickup and cable. Note the similarity to the Odyssey. Courtesy of Matrixsynth.
A guitar synthesizer created by ARP Instruments, first marketed in 1979. The Avatar was built around the guts of an Odyssey, their popular monophonic performance synth. To this, ARP added an input for a hex pickup, priority circuitry for selecting which string would trigger the synth, a pitch converter for generating the control voltage, a trigger circuit, and an envelope follower for tracking the guitar's dynamics. As a bonus, ARP also put in an effect called hex fuzz, in which each individual string input was put through a distortion circuit and the outputs of those mixed; the hex fuzz had no connection with any of the synth circuitry. Unlike its primary competition, the Roland GR-500, the Avatar did not come with a dedicated guitar; instead it came with a hex pickup which the user could mount on a guitar of their choice.
The Avatar made a splash when it was introduced, but the street buzz quickly turned negative. Users soon discovered that the pitch and trigger circuits tracked poorly and could not keep up with fast playing. Wrong notes and missed notes were common. To be fair, some of the problem was caused by users ignoring ARP's advice on what kinds of guitars the synth could be used with; some users mounted the hex pickup on hollow-body guitars, or twelve-strings, or other types of guitars besides the recommended solid-body guitars. However, even when all of the instructions were followed, the synth did not track well. There were also some power supply overheating problems. And because the synth's controls were all mounted on the panel of the Odyssey-like case, it was inconvenient for guitar players to alter patches during or between songs. (The GR-500 had both on-guitar controls on its dedicated guitar, and foot switches on its on-the-floor synth enclosure.) The list price of $3000 (in 1979 dollars!) also hurt. Sales quickly dropped and many of the purchased units were returned for service to try to correct the tracking problems.
ARP had invested nearly all of the company's resources in developing the Avatar, and the company was desperately hoping for Avatar sales to replenish the coffers. When that didn't happen, the company quickly fell into financial trouble. Lack of Avatar sales meant that ARP didn't have money to complete the Chroma, which might have saved the company, and ARP was forced into bankruptcy in 1981, about 18 months after the Avatar's introduction.
Today the Avatar is moderately sought out by collectors -- but not as a guitar synthesizer. Most performers who have one use it as an expander module or as a substitute for an Odyssey; they ignore the guitar input and instead control the Avatar via its CV/Gate input jacks. The resale value of the Avatar is not that high, so performers who would not dream of altering a highly collectible Odyssey don't mind modding an Avatar.