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My TV has two RCA female connectors for audio output. I assume it is the line-out. No female jack connector specfic for headphones.

I want to connect usual headphones that has a male jack connector. I've buy an adapter "two male RCA => one stereo jack" (Y-cable) and everything seems ok, just volume a few low.

However, after read wikipedia:

https://en.wikipedia.org/wiki/Line_out_(signal)

it seems this is really a bad idea, headphones has not the valid input impedance, and that can cause low sound, damage my TV, and an economical world crisis.

Any hint?

Addendum:

According to samsung (see here), the solution is the Y-cable. It seems they are not worried about impedances (and, in photo, it seems they are not worried about what is RCA or jack ?).

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closed as off-topic by Scott Seidman, Nick Alexeev Oct 17 '16 at 2:53

This question appears to be off-topic. The users who voted to close gave this specific reason:

  • "Questions on the use of electronic devices are off-topic as this site is intended specifically for questions on electronics design." – Scott Seidman, Nick Alexeev
If this question can be reworded to fit the rules in the help center, please edit the question.

  • \$\begingroup\$ There are plenty of headphone amp ic's ranging from the obsolete (if still popular) mono lm386 to modern power efficient stereo chips intended for portable electronics with low supply voltages. \$\endgroup\$ – Chris Stratton Oct 15 '16 at 18:30
  • \$\begingroup\$ Thanks for the comment. Any IC in particular to start looking at? \$\endgroup\$ – pasaba por aqui Oct 15 '16 at 19:05
  • \$\begingroup\$ That depends on so many factors such as if you are willing to deal with small surface mount, if you want mono or stereo, what supply voltage you have, and is a moving target too. One thing to do is look for hobbyist modules and see what chip they are using, for example when I look I see several using the TDA1308. \$\endgroup\$ – Chris Stratton Oct 15 '16 at 19:07
  • \$\begingroup\$ Addendum add, with information from the tv manufacturer. \$\endgroup\$ – pasaba por aqui Oct 15 '16 at 19:09
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    \$\begingroup\$ I wouldn't give much credibility to the link you found, the picture there doesn't even match their description... there's a high chance that came from a marketing department without input from the engineering one, if it even came form the manufacturer and not a 3rd party. \$\endgroup\$ – Chris Stratton Oct 15 '16 at 19:12
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That Wiki page sums it up pretty clearly. Except for the world crisis part, you mentioned.

Why not use a commercially offered amplifier designed for the purpose? These days, there are fewer available amplifiers (in the US, anyway) which are designed only for this purpose (you usually have to buy more than just an amplifier), but they exist. They are rare these days and usually only supplied to "tube" people, now, it seems. I kind of hate the fact that the market for a simple stereo amplifier has dwindled down to such a small market. But it has. That said, for example, something like this will do the job quite well and it does exactly and only the job you want done.

I don't know your limitations, though.

You could also consider the idea of making something. If so, would you prefer a kit amplifier, an IC solution, or discrete schematic? If you are posting here, perhaps you are comfortable approaching one of those?

Regardless, you do some some kind of active amplification. It doesn't have to be complicated. And you'd have to decide if you want the two RCA sides combined into a mono-output or if you wanted stereo retained. But it will need a source of power, whether battery or otherwise.


Interesting catch from Samsung. I still wouldn't go that way. It doesn't seem correct to me. You already mentioned that the audio seemed muted to you. I think that tells you what you need to know, here..

You might consider something like a TDA2822, for example. It's a stereo IC and will operate off of low voltages. But it lacks an intrinsic volume control and may be a little over-powered for your needs. The TDA7053A is also a stereo amplifier, with a built in volume control, but it is bridge-tied and headphones usually have a common ground. So when reading these, you need to be aware that you probably want single-ended operation. Search around for something still closer than those two I just found. They are usually very easy to use. (EDIT: Just saw the TPA6021A4 show up on a search, which at first glance looks closer. I'm not going to read the datasheet fully for now, though. But you might check it out. They are available at the usual suspects, Digikey, Arrow, and so on, for about $2 each. It operates both as single-ended and bridge-tied. Also, TI has an evaluation module that retails for about $50 called the TPA6021A4EVM. Here is the user's guide for it. Look at Figure 3 for a headphone connection that may work for you.)

The value for \$V_{pk}=\sqrt{2 P R}\$, plus a little for whatever overhead is required. That's \$V_{pk}\$ and not \$V_{pp}\$ so if using a single DC supply keep in mind that you'd need twice that value and more for a DC supply rail. But I think the power you require for headphones is very modest, so it's likely that whatever voltage supply you use, so long as you have a way to control the volume, will work.

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  • \$\begingroup\$ Thanks for the answer. I prefer to skip usage of wireless headphones. Could be better use some active based on operational amplifier / instrumentation amplifier, powered by a 9v battery. \$\endgroup\$ – pasaba por aqui Oct 15 '16 at 16:43
  • \$\begingroup\$ @pasabaporaqui The link I provided isn't wireless. It's a DC powered tube-preamp + transistor output amp device specifically designed to solve your problem. However, it's pricey because they are selling into a "tube" marketplace and requires a lot of power. If you are willing to construct something, then that's a way to go. What's the ohm rating on your headphones? 32? Or? (Some get up into kiloohms, in some cases.) Do you need a volume control? Lots of questions. You may need to update your question a bit to fill in details. \$\endgroup\$ – jonk Oct 15 '16 at 16:47
  • \$\begingroup\$ Why down votes? I do not see any thing incorrect in the answer. \$\endgroup\$ – pasaba por aqui Oct 15 '16 at 18:52
  • \$\begingroup\$ Addendum written to the question. In this question, I'm specially interested in comments like "usually RCA outputs are protected to low impedance devices", etc. The possibility of construct my own amplifier is interesting, but then I will open another question with all required details. \$\endgroup\$ – pasaba por aqui Oct 15 '16 at 19:06
  • \$\begingroup\$ @pasabaporaqui Added some additional comments. \$\endgroup\$ – jonk Oct 15 '16 at 19:19
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The TV probably uses an Op Amp to drive 1V line out so consider external Y to 3.5mm jack with 3.5mm plug from portable powered speakers and plug headphones into speaker jack.

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