I’m restoring my old Juno 60 and it has gone well until, while testing, I discovered that the top octave is sort of screwed up. Any note pressed there plays two tones that are in tune with anything. The tones do get high with higher key presses. The octave transpose switch makes the tone lower and/or higher but still out of tune. Also, it doesn’t matter which oscillator are on, but you can tell which are being used: one of the tones will have the timber of the chosen waveform. Not sure what the other tone is.
My repairs have consisted of mainly cleaning the key contacts with contact cleaner, specifically Deoxit. This solved the issues it had before: keys multiple triggering or not at all and retriggering when keys were let up.
I don’t think it’s in the keyboard. I’m afraid it’s an electronic problem.
Has anyone experienced this behavior? Any ideas about what I’m looking at?
More info about this issue:
1 - It doesn’t happen if it’s the arpeggiator playing the notes. ie, play a chord just below the top octave, engage arpeggio and switch it to two octaves. All the notes play fine.
2 - The second note is not random. It’s a sharp 5th above the played key. eg, play a C and it plays with an accompanying G#. The same interval is played on all the keys, all the keys in the highest octave, that is.
So it’s not as random as I feared. There’s something logical going on.
Again, any help would be really appreciated.
Well, I guess I’ll have to dive in and sus out how notes get triggered from each octave. And then to figure out why an extra note is being played 8 half steps above the key pressed.
If anyone knows how this all works or where I can find such info, I sure would appreciate a pointer.
there’s a bridged contact somewhere, most likely a loose solder blob or scrap piece wire in the key board matrix. You just have to keep searching, going over everything you touched.
Thank you. That’s a good idea. The search is on!