On The Inside

On The Inside

Friday, November 20, 2015

Technics 1200s, the Last Repair

If you DJ, and you play with vinyl, then you've probably had to deal with the annoying repair of the RCA cables that are permanently attached. I've repaired these numerous times for friends. Recently, my own 1200's started developing cable problems that can't be fixed by just wiggling the cable a little bit :)

I don't enjoy this type of repair, and I don't think that it should be necessary, so I decided to just modify my decks to not have to deal with this ever again. In the process, I switched my decks to self grounding via the signal connector. This is a potential safety and noise issue, but with how we're using decks these days, I'm not convinced that either are really relevant. That said, I like to live dangerously, "you" shouldn't do this without consulting your lawyer, your city or county building codes, an electrician, your grandmother, a priest, and perhaps a fortune teller just to be on the safe side.

Basically, I'm going to add some jacks to my turntables so that I can just use any set of RCA cables, and in the process, I'm going to eliminate the ground wire.  If you take your decks apart, you will find the tonearm area underneath a steel cover. It's removed here, and I have the new cover with the jacks and wires soldered in place.

The steel cover could be modified, but I think that this is neater.
I used a scrap piece of PC-Board material to make the replacment cover, and drilled a couple of holes to mount the RCA jacks. Pay attention to the positioning, you don't want to bump into the circuit board or any of the tonearm metal. The lines on the plate were to help me position the holes. The circle is drawn with the plate and bottom cover in place.

In the next picture you can see the plate bolted into place. Remember kids, red is right, everything else is left. You want to mark them to avoid strange phasing issues later when you're using two decks. It doesn't really matter much otherwise. 

With the back cover in place, I hope that you can appreciate the wisdom of taking the time to mark the opening.  It's working perfectly, no more dropouts or mysterious hum in the middle of a session.  Cables may still go bad, but now it won't take the better part of an afternoon to repair them, just unplug, toss, and replace.

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