“This Prophet 600 looks amazing for its age. All the knobs function and all LEDs light up in response to the touch pads. I re-loaded the 100 factory preset programs back into it to give it a fresh start and they play,sound and match their descriptions OK. I’ve never had this keyboard worked on and after ten years of home studio use followed by 23 years of storage in my closet here’s what went wrong:
1.) On a few programs, some keys are dead or weak, while in the rest of the programs all the keys sound out as they should. It exhibits this behavior since I pulled it out of storage. I probably should replace the battery but I don’t want to put any work/money into it unless I could verify it would fix the problems.
2.) Tunes itself OK but, it seems like an oscillator gets a little wavy at times. (De-tuning noticed during chords). The oscillators have never been tuned, gets a little better as it warms up
3.) That being said overall this synthesizer sounds great and I believe a little technical service will revive this rare and (truly vintage classic) analog synthesizer. NOTE: While taking photos I noticed it appears to have been factory signed. Pretty faded though” Click here to search for synths on eBay