Grateful Dead Music Forum

A place to talk about the music of the Grateful Dead 

 #139356  by HeadSpace
 Wed May 28, 2014 11:05 am
Hi all:

The on-off switch (rotary type) on my MC2120 has gone south on me--the spindle just spins uselessly and does not click into either on or off position. McIntosh tells me the part is no longer available AND there is NO available contemporary equivalent. Unfortunately, the amp is stuck in "off" mode, so I am totally out of business as a result of this failure of a simple part.

I am wondering whether, as a last ditch solution, the amp can be "hardwired" on, and then shut on and off via power conditioner, switched outlet strip, etc.

If so, how straightforward is this likely to be to do? I am reasonably experienced with a soldering iron and would certainly be capable of cutting two wires off the broken switch and soldering them together to complete the circuit if that's all that's involved. On the other hand, I wonder if the switch might contain some kind of resistor that would need to be replicated or...any other consideration here?

The thing weighs about 700 pounds, so shipping it off to Terry DeWick or whoever is not feasible, which is why I'm thinking of the DIY approach.

I humbly solicit any advice, answers, words of wisdom, etc. from the resident electro-gurus. Any help greatly appreciated.

 #139357  by schmidtz
 Wed May 28, 2014 11:17 am
It will be as easy as soldering two wires together. Open up the chassis and you will see two wires that go in to the switch, when they are connected it is on. An arguably more professional way to do this would be replace the rotary switch with a toggle switch like the ones found on the back of a twin reverb. I think Carling is the most reputable manufacturer of those types.
 #139362  by HeadSpace
 Wed May 28, 2014 12:19 pm
Thanks! That's what I was hoping to hear. I will also explore the toggle switch idea, which is a good one, obviously. Thanks again.