Replacing pushbutton switches on a C33 or C34V

jlovda

Things I loved from the 60's and 70's
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One of the eight pushbutton switches on a C34V I am working on is defective. Has anyone successfully removed one and replaced it with a new one? I have to contact Mac Parts on Monday and see if they are still available.
 
My C-34 Mac charts.jpg tone controls failed on one channel and returned the unit to Audio classics for repairs. The tech had to remove the switch bank and repair or rebuild one of the switches. Ryan says it happens rarely but often. enough to keep the tech on his toes.. It's not cheap, but they check everything out and give the pre-amp a diploma. Imagine having a MC 225 built in your pre-amp with lower distortion and better signal to noise. Where are my Klipschorns? Actually the little amps drive electrostatic head phones nicely.
 
I had to replace the momentary push buttom of a C33. Mouser has the switches, I bought a bank and removed one to use to rebuild the C33s. Removed the latch function. Kept the bank to always have some around and have used a few in other non Mac units.

Mon. I can get you the mouser numbers, I think it is still in the bag.
 
I had to replace the momentary push buttom of a C33. Mouser has the switches, I bought a bank and removed one to use to rebuild the C33s. Removed the latch function. Kept the bank to always have some around and have used a few in other non Mac units.

Mon. I can get you the mouser numbers, I think it is still in the bag.
I did not look really close because the switches are buried under the tone board. Are all eight switches physically connected together as an assembly? Do all eight switches have to be removed together from the circuit board, at which point the bad module can be separated and replaced? There seem to be 12 pins on each switch module that would mean unsoldering 72 solder pads for removal. Am I right?
 
The switches can be connected together but in this case you just have to unsolder the bad one.

I probably have a picture of the assembly but not here at home.
 
The switches can be connected together but in this case you just have to unsolder the bad one.

I probably have a picture of the assembly but not here at home.
I probably have the same issues with C33, it will great to see some pictures and some comments on the parts. My regards.
 
You might have noticed that Chris / c_dk passed away three years ago, thus the RIP under his name. He probably will not respond.
 
I've had great success cleaning those switches to get them working. It pays to disassemble them to do so, don't lose the spring, and they are fiddly to reassemble to get the right action. But once clean and reassembled properly they work well again.
 
The switches on my C33s were sealed plastic with no way to open without destroying them--I had the board out and oriented it so the deoxit flowed directly into the switch, and they were still randomly intermittent. Did you remove the front springs?

Super cheap switches but kind of a pain to replace.
 
Well I've officially lost my mind. C34V is too close to MAC4300V, I guess. I was talking about the 4300V switches!

Feel free to ignore that ^
 
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