ARP Avatar

ARP Avatar synthesizer
ARP Avatar

The ARP Avatar is very similar to the Odyssey but instead of a keyboard it was designed to capture the notes and articulations being played on a guitar and use that to control the synthesizer. So I guess the synth is supposed to be an “avatar” of your guitar? Seems kind of sad. Never mind that though, the owner of this Avatar wanted all that guitar-related stuff taken out, so it will be controlled with a sequencer or another keyboard synth.

Service Tips:  I’ll do this to every ARP I can because it makes them much more reliable and I think it saves money for the client in most cases by dramatically cutting down on troubleshooting. In addition to the full recapping mandatory on all ARPS, I also replaced all of the LM 1458 and LM 301 op amps and certain CMOS ICs which I have observed to have high failure rates in past ARPS… reflowed every connector pin with new solder and built and installed a whole new replacement power supply. ARP used different power supply designs in different synths but the one that is in this one is the same as the one in the Omni and it’s terrible.

Work done: removed guitar processing circuitry, washed this very dirty synth inside and out, cleaned and lubricated sliders and switches, reflowed all connector pins, replaced all polarized capacitors and aforementioned op amps. Modified filter with component value changes to improve range and self-oscillation capability.  Built and installed new power supply. Had to troubleshoot AR and ADSR that didn’t work (one bad 2N6076 transistor in the former and three in the latter, replaced with BC558). Ring mod not working was caused by bad 4011 NAND gate; noise generator not working caused by damage on the board and disintegrating jumper on noise routing switch. Rewired output to bypass the convoluted mixer that would have mixed it with the guitar signal, but in this case was only adding noise and eating up its amplitude.

This is not the last we’ll be seeing of this Avatar. In fact, I’m just getting started as I am about to get into doing some pretty crazy mods on it.  I’ll post about those when I’m done!

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