Salvaging a 1977 Peavey MC-12 Mixer

[Beo]

I picked up a Peavey MC-12 Mixer used for 25 bucks. At a minimum I was hoping to be able to use the 1/4" jacks, but was also curious to see what other components might lie under the hood. When I bought it, I had no idea how old it was. The only thing I have to go on is the dates on the circuit assemblies which say 7/77 and 5/77. I could research serial numbers I suppose.

Anyways, the jacks look great. Switchcraft enclosed PC mount type. Also, well over 50 RC4558P opamps in sockets! The pots are 25mm with plastic shafts... and over 20 years of possible use... so I'm not sure they're of much use.

So, check out the photo's below. What do you think is worth reusing in a stompbox?

Travis

[Beo]

Check this out, it's got a spring reverb as well!



The reverb chassis has an RCA jack input and output. Anyone have any good links on how to turn a spring reverb into stompbox or rack effect?

[Skruffyhound]

Gausmarkov has a design on his site. Google. Good luck

[petemoore]

  Schematic will help.
 Power suppy capacitors are questionabley tosscan items [cap checker handy?], but the iron/etc. is probably all good.
 the schematic may help you reconnect the reverb tank/driver/mixer etc.
 The panel asks how far across the panel can you extend your other toe foreward from the foot you stand on?
 The rest of it...socketed opamps etc.
 I'd consider setting up a testing jig for the channel strips, maybe build an quadra-EQ'd-Fuzz or some parallel fade-circuits type stuff. A little preamp with some Eq on it is a mighty handy item at times...not exactly 'tidy' but could fit in something already large-ish?
 decades ago, I'd say rebuild it and then try to find or put together a 're-up-kit' for old boards like that...either replace dodgy components or the whole channel strip that was dodgy...that was back in the day though, these days it's 'easier' to have a like new, new, mass produced mixing board.  

[Hides-His-Eyes]

What a find!

Pots would probably be fine after a good spray of contact cleaner

[benl560]

hay! i have one of those.  one of the channels dosnt work, but im not too curious as to why. i use it as a drum mixer for jam seshes.
cant believe they socketed all of those opamps...

[Beo]

@pete, I wouldn't use any of these strips as is... too large. I plan to desolder anything that might be useful.

@HidesHisEyes: to fix up pots with contact cleaner, I assume you need to open the tabs and remove the pot cover?

Anyone know a good way to remove tarnish and gunk from metal components, particularly the threads & nuts for the 1/4" jacks?

[Skruffyhound]

WD-40 and wait overnight. Alternatively blend up some white spirit and a light oil, paint it on. That will loosen things up. Tarnish is for life, but it's mojo. Gunk is removed with white spirit (or lots of other similar solvents) and elbow grease.

[Hides-His-Eyes]

@HidesHisEyes: to fix up pots with contact cleaner, I assume you need to open the tabs and remove the pot cover?

nah, just spray it in the hole.

[wavley]

I believe that thing had transformer balanced mic pres, you could use them to make mic pres, or you could give them to me