Juno-106 Oscillator Oreo

Found a Juno-106 in a dumpster and I have been working to restore it. The serial number tag is gone. The key bed has a build date of January 21, 1984. The filter chips are 1A and 1B so this is a VERY early Juno. After watching a TON of videos and doing research, I cannot find in any instances where voice oscillators are stacked like an oreo and soldered together. MY best guess, this is someone’s repair attempt. Anyone else ever seen this before?

I know this is an old post, but yes… the 106 initially used 6x wave generators, one for each voice. They later moved to putting 2x wave generators on one “chip,” sharing the waves between two voices.

Thank you SO much for the reply. Knowing that this is indeed “factory” I will leave these alone and only worry about the oscillator stripping. It really seemed like an aftermarket “hack” thus I became concerned someone had done this to skip properly replacing the filter and simply tacked something on. Note: of the four osc boards I have stripped, I found several failed solder joints under magnification and did a re-flow on them even though these were NOT expected to have any issues due to the estimated production date.

Believe it or not, I am STILL working on this unit, its a pet project that has had delays due to getting replacement parts. I’ve replaced caps as I go along with a known good quality brand so this 106 should last a long time once its running. Switches FINALLY came in and all my tactile pushes got replaced (old ones had rust). I also cleaned and tested ALL the slider pots and CAREFULLY cleaned, serviced and tested the HPF switch. I thought I had lost the little indent bearing ball of the switch but it was stuck in dried up grease. It was a heart racing moment for sure! I have also taken the time to properly clean the yellowed factory coating and my flux marks from all my solder work. I sealed the PCB control board with an acrylic final coat. I’ve done this for all the other boards I’ve gone thru.

I am down to the jack board and the filter board to finish. I also need to do a good deep cleaning and polish of the keyboard keys and bed. I have two penny sized spots of rust to take care of on the keyboard frame but that should not be an issue long term.

It’s been difficult to identify the age of this keyboard. The serial tag is missing and that makes me think it was listed as an asset somewhere and taken off when trashed OR it was stolen. Best I can tell from a date stamped on a part, January 21st, 1984 and the oscillator has a “3DA” date code this unit was a very early production run.

I was a “Hooters” fan in the 80s and loved the music Rob Hyman did with the 106. I still can’t believe someone tossed this in a dumpster. Before I even started work, it had value to it


Sealing the control PCB with Acrylic


Top side finished control board with Syntaur slider protectors


Re-installed control board with a couple replacement Syntaur slider caps


Jack board in need of some repairs. Jacks will have to be replaced


Cold solder joint found on connector of Jack board


After a couple weeks, new 1/4 inch jacks are in and I started installing them to the PCB.