HELP: headphone/TV RCA connection

I have a pair of normal (unpowered) stereo headphones that I would like to connect to my rear projection TV without using a stereo receiver in between them. Since I can't see any headphone jack, it appears that my only option is to plug into one of the pairs of RCA jacks provided for output to a stereo receiver.

** How do I make a proper connection between these two connectors? Will the adapter off the shelf from some big name comsumer electronics store be the right thing?

Since there's no way to only mute the TV's built-in speakers, if I had the choice (i.e., something off the shelf won't work), I would like the volume in the headphones to be noticeably louder than the apparent TV speaker volume under typical listening conditions. Perhaps the "adapter" could include a volume control.

My TV is a Sony KP-57WS510. The TV OUT RCA jacks are: 500 mVrms, 1 kiloohm impedance

My headphones are Sennheiser HD 535's (older version of the 555's). They are dynamic/open with a 120 ohm impedance and a sound pressure level(1 kHz, 1 Vrms) rating of 103 dB.

Reply to
gjanusz8
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Quick idea:

Use one of these:

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and use something like this to connect the two male ends?

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Reply to
mrdarrett

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Ah, yes. I should have been more specific. I know how to physically make the connection, but not how to ensure there is an "electrical" match between the TV and headphones.

I'm particularly suspicious of this TV connection, since I've never been able to find a resource that can explain why I have to turn my stereo receiver all the way up so that there is normal volume coming out of my headphones when plugged into the receiver. (I've tried setting my TV audio to fixed volume mode--no difference; standard 75? ohm cable).

Reply to
gjanusz8

If they do not output headphone-level signals, you need an amplifier. That's what amplifiers are for; that's why they are manufactured.

Reply to
mc

The operative word is "if." That's why I wrote my post.

Reply to
gjanusz8

Right... RCA jacks normally output line-level audio, not headphone-level.

Reply to
mc

RCA output with a 1kohm source impedance aren't going to drive headphones very adequately.

Graham

Reply to
Pooh Bear

Depending on how aggressive you want to get about this, you may have another option. (Decades ago when they started cost cutting there was something called "hot chassis", which was where some parts of TVs of that era might have 115 volts present on metal parts inside, to save the price of a transformer. That presented some risk if you were going to get into modifying those and didn't know what you were doing.

But I don't think there have been hot chassis in a long long time. It looks a lot more common for most of a tv chassis to be one or two tiny circuit boards, a few chips, and more likely to run on 5 or 12 volts than 115.

So, considering that safety issue, it may be possible for you to turn off the set, let it gradually discharge for a while, open the case, splice into the wire from the chassis to the speakers, find or drill a small hole in a convenient place on the plastic case, mount yourself a little jack and create an external headphone jack.

That is just an option, or maybe not, depending on your skill, experience, and willingness to consider this before you decide whether or not to do this. (I got a new TV years ago that seemed a little to cheap. It turned out to be the end of the line with sets that don't have all the various new connectors and features out the back. But now it has a headphone jack in the side of it)

Don't get yourself into trouble.

Reply to
Don Taylor

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Usually you need a maximum power of 50 to 100mW for a decent level in the headphones. Most headphones are 32 Ohms today, so when yours really have

120, the normal O/P would give you only a low output. Try to wire the phones directly to a spare normal speaker terminal of your stereo with a resistor of 470 ohms/1W in series, so they have some protection. Very often the volume of the TV is limited by the satellite receiver, which has sometimes its own volume control on the remote. Check that also out.
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ciao Ban
Apricale, Italy
Reply to
Ban

The last three responses had the kind of info I was looking for. Thanks! It seems like I need to find a pre-made (or schematic) for a headphone amplifier (w/ volume control) that uses RCA jacks as its input.

Reply to
gjanusz8

you need a headphone amplifier.

the sterio outputs will probably not be effected by the TV's Volume setting. (so you can turn the TV volume right down and use the headphone amp to adjust the sound level for comfort)

you could try without the amp.. just a RCA to headphone adaptor. at 120 ohms they may work acceptably at line levels... still if you're buying Sennheiser phones it'd probably not be acceptable.

Bye. Jasen

Reply to
Jasen Betts

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