Up for auction is a ARP 3620 two voice polyphonic dual memory circuitry keyboard. A built-in LFO gives expressive vibrato for use with any or all of the 2600 oscillators or other functions. The keyboard has foot switch jacks for portamento and interval latching along with in and out jacks for other functions. If you own a 2600 you need this keyboard.  Included are a copy of the owner's manual and a copy of the Service Manual. (copies, not originals). Service manual explains calibration if needed to your 2600. As with all vintage electronics, unit is sold as-is, but as described working but may need calibration to your 2600.  Paypal or certified funds only. Flat rate insured shipping to the lower 48 will be $65.00.  Please ask all questions before you bid. Thank You for looking at this rare piece of keyboard history!