Hi, I have found an half priced Jupiter 4 in very good cosmetic conditions, but seller says that:
by pushing the same key for 4 times, there are 3 notes which are ok and the 4th sounds around an octave lower. It also happens in poly mode.
The synth, in these conditions, should be a full working 3-phonic synthesizer, isn't it?
Which could be the damage? Is it just a question of properly setting the tune's potentiometers on the back (may be with a voltmeter or an oscilloscope) or is there the possibility to have a serious damage? Thanks.