Wednesday, August 8, 2012

Stupid Adapters

Every once in a while you run across something stupid in an audio system. Like the time I was redoing a church system and found six feet of cable between a CD player and the console that was comprised entirely of Radio Shack adapters. Or when I ran across this little gem in a cabinet at work.
XLR-M to Stereo RCA-M

Now that's a male XLR so it's looking for an output. Console mono out (+4) to tape deck in (-10) anyone? Yeuch! I threw that one out without even a second thought, pausing only to document the find on Facebook. The big deal here kids is that a console out is 14dB hotter than what a record deck (unless it's a pro level one) is expecting to see from a unity level input. A lot of desks will have a separate level control for a summed mono out but there are better ways people, there are better ways.

1/4" TRS to RCA-F
The next stop on our trip through the Museum of Misfit Adapters is one that is actually sold over the counter, most notably at the aforementioned Cell Phone, erm Radio Shack. You can be the proud owner of a pair of these beauties for just a hair over six bucks. The question is this: what the hell are you going to do with these suckers!?

If you put one of these on the end of what is commonly called an iPod cable these days (1/8" TRS to Stereo RCA Male) you're not going to get a peep out of it on the console. The reason being is that most inputs on consoles are balanced in, which means that there's a "hot" signal on the tip and a "cold" signal on the ring with a common ground on the sleeve. That cold signal is the same as the hot signal but with reversed polarity with respect to ground. A balanced input will use those two signals to reject noise and admit only the intended signal. In this configuration though, the "hot" from the RCA shows up equally on the tip and the ring and is effectively cancelled by the differential input. Same goes for an output by the way. Use one of these babies to feed a recorder from a balanced out and you won't get much if anything.

The only possible use I can think of for one of these is to take a stereo headphone out and sum the two channels to a single input on a tape deck. Yeah...  Now this beastie's more common sibling, the 1/4" TS to RCA-F is exactly what you want for connecting that iPod to the console. So check your MacGuyver box and make sure if you have any of these that you toss them. While it's true that you can get them to pass audio on a balanced input by only pushing them part way in, save yourself the hassle and for six bucks just get it right.

Well Brethren of the Knob and Fader, what misfit adapters have you got lurking in your box, or have you spotted out in the wild. Let us know in the comment section or on Facebook.

1 comment:

  1. Where's that midi to 3ph camlock you're always talking about?


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