How can I get my noise-cancelling headphones working on my old TV?

February 7, 2004 1:31 PM

How can I get my noise-cancelling headphones working on my old TV? [more inside]

My family has a TV in the basement in front of a treadmill, so that my mother can watch TV while she works out. Of course, there's a problem: the treadmill is extremely loud, and when she turns up the TV so that she can hear it over the din, everyone else in the house (and the county, for that matter) can hear what she's watching. We bought a set of noise-canceling headphones, hoping they would be the answer, but promptly discovered that the well-worn TV lacked even RCA outputs, much less a headphone jack.

Forging ahead, we purchased the wires needed to convert RCA to mini jack (more as a proof-of-concept that we could pony up the cash for any new TV and have it work), but found that our RCA-equipped TV's output a signal intended for an amplifier -- i.e. a steady-volume signal that is almost inaudible on headphones. Thus, we were once again foiled. Do we need to purchase a new TV with a headphone jack (meaning that we might not even be getting a good TV for the money)? Or is there another clever solution that we haven't thought of?

posted by Ptrin to technology (3 comments total)

This isn't a very efficient solution, but you could probably go to an electronics store and pick up a cheap boombox with an RCA input and a headphone jack...effectively spending $50+ on a crappy headphone amp (are there cheap deficated headphone amps? The only ones I've heard of are expensive audiophile gear). On the other hand, your mother could listen to the radio too.

Might you have an old reciever or minisystem lying around the house?
posted by kickingtheground at 2:04 PM on February 7, 2004

The thing is that you'll need not only an amplifier, but also independent volume control, since the TV output is fixed-volume. So yeah, it sounds like a cheap receiver, boombox, or bookshelf system with RCA inputs is the way to go.
posted by jjg at 5:58 PM on February 7, 2004

Ptrin, if you're handy with soldering, it's cheap and easy.

However, I have a feeling you might not be... :-/

Please, whatever you do, DON'T OPEN THE TV. There's 22,000 volts in there, *and* on some TVs the chassis connects to live. It'd hurt like hell if you put that on your head, probably even kill you.

That out of the way, here's the circuit you need. Also, here's a pre-made booster that would likely work for you too (not sure, but if you hooked two in series, it would definately be good enough).

Don't you have a crapped out stereo handy? Check your local junk-shoppe. Shouldn't cost much more than $10 to do this if you don't mind a big honking 1970's amp under the TV.

(If you need that built, I'd do it, but nowadays buying individual parts often outweighs the cost of a professional unit).

Last option: Buy a TV with a headphone jack (yup, they exist! -- usually the little tiny 4" $30 B&W models).

HTH!
posted by shepd at 11:59 PM on February 7, 2004