What do people use top clean the j-wires and buss bars on their classic Moogs?
Is rubbing alchohol good for this?
De-Ox-It?
My MultiMoog is having problems triggering notes properly. Everything else seems to be working fine, so I’m assuming it’s a key contact issue…
But wondering if the after-touch assembly could be responsible for this erratic key triggering also?
First, check to see if the ground wire on the left side of the keyboard is still securely fastened to the metal keybed. If this is loose, it can cause false triggers.
Otherwise, alcohol and swabs are recommended if the bars and contact wires are not corroded or heavily tarnished.
Never use any Caig product on key contacts (or anything else in my opinion, but especially not on key contacts.)
I’ll check this, thanks.
I didn’t notice any corrossion or even much of any tarnish. I used ethyl alchohol and a cotton swab to clean the key wires and buss bar (long bar/wire running along bottom - this is what it’s called I think).
It did not really help; The keys are still very slow to trigger. I have to press each key several times and/or move it side to side a little in order to get it to trigger at all. Even then, the note won’t sustain alot of the time.
Is there anything else that could be wrong? Is there a specific way to clean the wires? I pretty much just swabbed them, removing any residue that seemed to be on them.
What are “Caig” products (so I know nort to use them)? I guess De-Ox-It is a Caig product?
Thanks for the help, I really appeciate it.
I’m not sure what to suggest.
Many things can cause this.
The Multimoog (and several other Moogs) uses a special circuit that’s not commonly found in other synths to produce a trigger. If this circuit has problems, an experienced tech is usually required because an oscilloscope is required.
Please make sure of a couple of things though…
Everything is clean. This type of trigger circuit degrades with any foreign substance on it. (spilled drinks, high humidity, etc.)
Check the wire harness inside to the left to make sure it is not rubbing against the keyboard’s aftertouch sensor. They are normally very close and the sensor can sometimes scrape wires above it, causing triggering problems (or complete failure!)
No external devices hooked up while testing.
And yes, Deoxit is made by Caig.
Caig stuff is great in SOME places as a temporary fix, but I don’t recommend its usage unless you know where and how much to apply. I never use it at all and I’ve had a pretty good success rate with synths, which should say something.
It can screw up certain circuits such as glide and key memory and attracts dust that causes friction. Key contacts should be clean and dry, never lubed with anything.
Best of luck, but I recommend using an experienced tech if you can’t get it flying yourself easily. If you need a service manual, I think I have some nice bound ones in stock for $20, but I’m not here to push sales. I hope you DO solve the issues.
Kevin,
Thanks again for your great help. Your posts here and on other boards are a great asset to the vintage synth user community. I hope that you do find the time and incentive one day to publish some of your vast synth maintenance knowledge.
I know that there has been at least one book published on the subject of vintage analog synth repair and maintenance (Troubleshooting and Repairing Electronic Music Synthesizers by Delton T. Horn), but I’ve had a hard time in the past tracking it down for a reasonable price.
Do you know if this is a good read?
I know that one is almost always better off taking a synth to an expert, but at the same time, I want to learn as much as I can about repairing my instruments-- and sometimes I feel like in order to learn, I just have to attempt some repairs myself.
I’ve only tried minor things so far, like using the trouble-shooting section of service manuals.
Thanks again
Hey Kevin,
If contracting out to work on the synths of only 3 “major stars” means that you will be around to give us all advice, it is almost worth losing you as a tech to work on all of our synths.
Hope that we don’t drive you buggy with all of the questions…
I’ve tried cleaning the key contacts again, this time with isopropynol, rather than ethynol. I looked at the service manual and it suggested isopropynol.
I think it worked a little better because the keys are responding more-- but they’re still not great.
I guess I’ll just repeat the cleaning over and over until it works properly, that or try to replace the buss bar. I’m pretty sure it’s the switch contacts because when I manually (with a tool) press the j-wire onto the buss bar, it seems to trigger OK. The more I look at it in the light, the more it looks to be tarnished and spotted.
I can’t say much about the Delton Horn books.
Not that they might not be useful, simply that I’m either already aware of what was written or it’s inapplicable to todays synth problems.
I’ve scanned through his various books and while interesting, I honestly didn’t find them useful enough to buy.
You may feel differently though and knowledge doesn’t hurt (unless applied wrongly 
One caution I should offer is that the problems of yesterdays synths are not the problems of today’s. At least not the only problems.
Back then it was unheard of to swap out electrolytic caps, detarnish silver contacts, eliminate IC sockets or even resolder the boards to effect a repair.
Nowadays, this stuff is done on every synth that passes through here FIRST, then I go look for any remaining problems.
Time and environment can really screw up a synth.
Even a synth never played and stored in a box from day one can have problems, especially if it has rubber parts, electrolytic caps (most all do) or silver plated contacts (ditto.)
Air gets to them and they do what metals and other compounds do: react and change state.
If bussbars and/or J wires are visibly tarnished (brownish, very yellow vs golden), there are some techniques to help out when alcohol won’t do.
Unfortunately, technique is everything here. It is VERY easy to damage these items if handled improperly and the only way to really know their limits or what works is often by making mistakes first.
For example, on these types of actions I will often desolder and remove the bussbars entirely. They’re polished by hand with a cotton rag and a paste chrome polish, rinsed and reinserted. But it’s not something I would tell someone to just go out and do because of how easy it is to bend a bussbar or remove too much plating.
Keep in mind that these synths were made at a time that gold prices were skyrocketing. Pratt Read used less and less gold as time went on.
The Cat SRM’s are a great example of this because they appear to have the lightest plating of any synth for that era and are very prone to wear, corrosion and mis-triggering.
If your buss bars are worn or grooved, you can also flip them around 180 degrees and use the side that was never touched, but they may still be very tarnished or have a latent atmospheric “gunk” (smoke, particulate matter, etc.)
My feeling is that your bars likely are clean enough at this point, but other factors are causing the issues.
Thanks for the kind words, though I’m not always an advocate of handing out technical advice. In short, I’m a lousy teacher and have my own tools, techniques, chemicals and other items that will likely be different than someone elses.
There are times I’ve tried to help someone and they mis-interpreted what I said, I wrote it poorly or they improvised outside of the important advice.
Since I can’t control that, it’s reasonable to assume that while I might well help someone, I may also provide confidence to others that really shouldn’t be working on their synths in the first place. I don’t want to cause more problems and that’s why I will say to anyone that if they cannot afford to break their synth, they should take it to a professional. A little knowledge can be a dangerous thing.
Still, if someone is itching to work on their own synth and feels confident and equipped to do so, a few pointers here and there can really help out.