Crumar RoadRacer

the Crumar Roadracer electronic piano
the Crumar Roadracer electronic piano

Another idiosyncratic instrument from the Italian company Crumar, who brought us such underappreciated un-classics as the Multiman S and a T1 organ that Darian’s working on right now. This is an example of a type of “electronic piano” that was briefly popular in the 1970s, when top octave generators and multi-stage frequency divider ICs allowed the architecture that had been used in the previous decade’s combo organs to be made much more small and compact.  Instrument manufacturers were making everything they could think of with this architecture– throwing it all at the wall and seeing what would stick. The “string machines” like the Multiman more or less “stuck,” but the compact electronic piano, not so much.

As banal and underwhelming as this instrument seems, it has two secret weapons. The first is a powerful chorus effect that is actually a 4-stage phase shifter based on the Electro-Harmonix Small Stone phaser. You can adjust its speed, but not its depth, and its always set to VERY DEEP. It’s a pretty radical effect for something casually identified on the instrument’s control panel as “CHORUS.”  The second fairly special feature is velocity sensitivity. The Roadracer must have been one of the very first instruments to implement velocity sensitivity, and I was truly surprised to realize that it had it. This is accomplished using a special gating IC called the AY-1-1320 “Piano Keyboard Circuit” and two keyboard buss bars. The amount of time that it takes for a key contact to travel between the two buss bars is what determines the velocity. Each keyboard IC is 40-DIP and controls an entire octave of notes. This IC was only ever used in one other keyboard besides the Roadracer.

Work Done: Rebuilt totally failed power supply with bad regulators and broken-off capacitors. Cleaned all controls, buss bars and key contacts. One thing about this velocity sensitivity setup is that the key contacts must be very clean on both sides and both buss bars must be very clean in order for it to work, and everything must be lined up very consistently. The actual keyboard feel is terrible, a really light and terribly shallow synth-action, which makes the fact that it has velocity sensitivity somewhat absurd.

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