Vox Jaguar with Missing Filter/Switch PCB

Heathkit Vox Jaguar

I don’t usually post about combo organ repairs because I don’t think they’re very interesting, but this was one of the weirdest ones we’ve ever done! The owner of this Vox Jaguar organ told us that he had had it for about 10 years and it had never made sound at all, which didn’t really faze us because that is a common complaint for a piece of equipment this old.  But when he dropped it off, we opened it up and discovered the reason that it wasn’t making sound was far more serious, and far more crazy, than we had expected. The tone filter and selection board, including the switch contacts, was missing ENTIRELY. The rocker switches were all present, but connected to nothing. The signals from the oscillator/divider boards were simply not being sent anywhere at all. Continue reading “Vox Jaguar with Missing Filter/Switch PCB”

Korg Trident MKI

I worked on this Korg Trident shortly after it had been serviced by a well respected tech, but it had been shipped home to Philadelphia and was unfortunately damaged in transit… a tragic event considering it was in great condition and was apparently working perfectly. The owner repaired the physical damage to the wood end pieces but took it to us because the manual controls and the piano / clavinet presets for the synthesizer section were inoperable. Continue reading “Korg Trident MKI”

new Buchla Music Easel – intermittent or “dead” touch keys?

Buchla Music Easel
Buchla Music Easel

Here’s a PSA about something we learned from a Buchla Music Easel (the new version) that we didn’t end up having to fix. We were told this Easel had an issue where sometimes, one or two of the keys on the touch keyboard just wouldn’t work. Continue reading “new Buchla Music Easel – intermittent or “dead” touch keys?”

Moog Rogue

Moog "The Rogue"
Moog Rogue

The Moog Rogue is very, very similar to the Moog MG-1.  It has pretty much the same internal design in the synth section, but the designers made some questionable choices about which parameters to allow control of– so unlike the MG-1, both oscillators on the Rogue have to have the same waveform, and be in the same octave. Continue reading “Moog Rogue”

Moog / Realistic MG-1

 I love these little Radioshack Moogs! I have a MG-1 of my own that I overhauled and heavily modded a while ago, and I’m always happy to bring another into the shop. They are so simple and there are only a couple parts that are hard to find– the sliders, the switches, and the MM5823 frequency divider ICs. This MG-1 was not in too bad shape, and the foam under the panel had mostly been removed already, but had one of the three divider ICs not working.
Service Tips
If you have several octaves of a handful of notes not playing, the MM5823 frequency divider ICs are the culprit.  I found a clever replacement solution from Flatkeys, a company in the UK— a little SMD board that fits right into the place where the original 14-pin DIP IC went.
There was also a slider with a broken wiper, but I couldn’t find any sliders of that type with the right value (10K) anywhere on the internet, so I bought a 2M one from Syntaur, took both apart and swapped out the resistive strips– as I was doing it, I was telling myself, “I am doing a ridiculous thing,” but it worked.
Work done: replaced all electrolytic capacitors, cleaned switches, cleaned and lubricated sliders, replaced MM5823 IC, replaced one bad slider, added 1/4″ output jack

Welcome to the Bell Tone blog!


Hi friends… So after 7 years of working on synths, I’m transitioning to doing this full time and I’ve decided to start blogging about my repairs in the hope that some of my advice might help other people on their synth repair projects! I always take notes on my repairs, so I figured I might as well flesh them out a bit more and share them here.

My focus will be on sharing less-than-obvious practical advice pertaining to the idiosyncrasies of certain synths (desoldering temperatures, part substitutions, where to get specific parts, etc) that I figured out through trial-and-error, so that maybe I can help someone else avoid the “error” part of the process. The internet has been a great resource for me throughout my time spent working on electronics, and I’d like to give back by helping out the next person who does a google search for “help arp omni traces ripping off help help help nooooo whyyyyy.”

Of course– I’m running a business so I’m also trying to connect with clients, so I’d be remiss not to say here now— if you have any analog or vintage synths, combo organs or Rhodes/Wurlitzer pianos in need of a little help, please get in touch!