Cheap and easy beginner switchbox
May 7, 2004 at 12:42 AM Thread Starter Post #1 of 1


500+ Head-Fier
Mar 7, 2004
Here's a real easy project for anyone looking for an RCA switchbox, or something to do one afternoon, as long as cost is more of a concern than sound quality (no pictures, the camera's not working at the moment, but we're not talking complicated stuff here. If anyone really wants pictures, I'll see what I can do). You'll wind up with a two input/two output RCA selection.

All you need are some Radioshack parts, a mint tin, and a few tools. Parts costs came to $12 or so -- two DPDT switchs (depending on model, $3-$5 each), the "Board with 8 Standard-Type Phono Jacks" (#274-370, $3.99), and the tin (I used a "Mintz" brand -- it feels pretty sturdy and the color matched the RCA board, $1.50ish. Not, unfortunately, available at Radioshack).

I did the case work first. All I needed to do was drill a hole on each side of the tin for the switches, and cut a rectangle in the bottom of the tin for the jack board. I just cut a big enough space for the RCAs to come through (not the entire board) and then hot-glued the board to the bottom of the tin.

Ideally, I'd keep the grounds from the different sources seperate, but a cheap DPDT doesn't allow for a third channel. Low-cost solution is to wire the grounds for all four pairs of RCAs together. If you label the pairs as 1, 2, 3, 4, I wired 1&2, then 3&4 seperately, and connected them with a wire that'd be at 1.5 and 3.5, instead of directly from one of the jacks. I have no idea if that's good audio construction or not, but it seemed like the least bad solution.

I put the wires on the switches before I mounted them on the case, since it'd probably be a bit of a pain to get them on after. Then I connected those wires to the jacks' input pins, and it's done. The only tricky thing is that the solder can get into the jack itself (you can see right through them), and prevent the interconnect from getting a real good grip on them.

How does it sound? Well... did I mention that it cost less than $12?
I can hear a difference with this, but it's a relatively light touch on my system's sound -- actually much less bad than I thought it would be. There's obviously noise coming in from the ground wire, but I expected that -- you can only really hear it when you've got one source playing, but the other one quiet but selected. Basically, I wouldn't want to use it as my switchbox forever, but it works quite well enough as a temporary thing while I plan something better.

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