Moog Music Forum

So I've just acquired a minimoog with a few 'issues' . Looking for any general servicing advice.
the machine is working more or less but has some horribly crunchy pots. I do have experience rebuilding old arcade machines so I'm not a total novice but I've never worked on synths before.

If I were repairing an arcade machine of that age I'd replace all the electrolytic capacitors whilst I was at it just to save me the trouble of having to open the machine up in the future. Would this be considered a good or a bad idea on the minimoog?

Is there any other preventative measures worth taking whilst the machine is on the bench?

I've been reading about the merits of replacing v cleaning bad pots.
http://www.soundonsound.com/forum/showf ... o=&fpart=1
what are peoples opinions on this?
Replace?
spray with some kind of cleaning product?
strip the part and clean with distilled water? Just how fragile are the carbon strips? Cleanable with a cotton bud or strictly no contact? Can't say I've ever succeeded in taking one apart and putting it back together. They tend to disintegrate on me but it may be the case I've never investigated a good quality one.

Any hints and tips would be greatfuly received.

Definitely replace the electrolytic caps -- as you said, theres no reason not to now since theyre so old, youre liable to be back in there in a month replacing one anyway. Personally, Ive found most pots respond to 1 part cleaner, 10 parts elbow grease
and if youre gonna replace em, just clean one anyway to see if you can get anything useful out of it, might save yourself a bit of work

Anyone tried this stuff?:

http://store.caig.com/s.nl;jsessionid=0 ... tegory=293

"DeoxIT® Fader F-Series is a precision lubricant specifically formulated to improve conductivity and lubricate conductive plastic and carbon compound faders, switches and other similar components."

Sounds like the right kind of thing?

I havent messed with that particular can but deoxit is a good brand of eletrical contact cleaner

Kevin Lightner strongly discourages the Caig products, he has had bad luck with them.

MC wrote:Kevin Lightner strongly discourages the Caig products, he has had bad luck with them.

+1
Solve a problem today, create another problem tomorrow.

How would you go about spraying solvent in a sealed pot anyhow?

schmidtc wrote:How would you go about spraying solvent in a sealed pot anyhow?

Usually by drilling a small hole in the back of the pot. Then you have a permanent hole which will allow even more dust and impurities. Oh, wait--now it's it's not sealed anymore .
Sometimes you can pry off the entire back and clean the wiper, but you have to really know what you're doing in order to reseal the pot without damage.
Best to just exercise the hell out of the existing pot, or replace it.

It might be worth trying to squirt your switch-cleaner in through the front, rather than drilling a hole in the back; assuming you can remove the control knob, just spray the solvent into the gap between the stalk the knob sits on and its sleeve, so to speak, using a the fine tube supplied with the spray can. I've just done this with my hi-fi amp and the Peavey combo-amp I use with the Voyager - in these cases, the control knobs simply pull off from the spiggot (lovely word that!) but you may have a grub-screw to contend with - and it worked fine. Then you just turn the knob back & forth a bit so the fluid gets worked in. Obviously, a Moog is not a hi-fi amp and might take umbrage at the very idea, but it would save drilling holes in the back of the pot. Of course, pulling knobs off spiggots may be forbidden in some states unless you are over 25.......in the UK, we can do more or less what we want, as long as there is nobody watching... But I guess if you are "lifting the hood" anyway, you may as well replace the pot while you are there.

I'm curious, which potentiometers are you having problems with? There are a few that have hard-to-find tapers and would be hard to replace, Emphasis (Rev Log 50k - not that hard to find, I think mouser has even started carrying them again), Glide ("5M No. 1 Taper - special Allen Bradey reverse log taper), and the Modulation pot (50k Audio, but must hit very close to 0 ohms at the end, otherwise you will have modulation leak-through).

As a side note, anyone know who made the opened back pots for the filter and ADS section on the minimoog?

I put up a page documenting my adventures in minimoog land.
http://www.clockworkrobot.com/minimoog/