Simple audio amplifier to drive headphones?

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geekIT

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#296322 8-Jun-2022 10:10

I need a simple audio amplifier to drive conventional headphones, for an elderly person with hearing problems. The requirements are: 240v power, left\right RCA inputs, headphone out, volume control, (tone controls not absolutely necessary but would be a bonus). There are many amps on TradeMe but most would be overkill for the requirements. Are there self-assembly kits that would do the job? Do you have an amp that you wish to sell? Could you build one for me?

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Awrrr
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#2923938 8-Jun-2022 13:34

What would you be plugging into it?

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#2923950 8-Jun-2022 13:55

if you build your own and plug a faulty 240V power circuitry to your skull, it won't end well

but hey each to their own!

Rikkitic

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#2923955 8-Jun-2022 14:04

No amp for this kind of purpose would require 240 volts. It would be battery powered.

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geekIT

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#2923978 8-Jun-2022 14:47

Sorry guys, forgot to say that this is for better sound while watching TV. The set has two unused RCA output sockets.

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Rikkitic

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#2923988 8-Jun-2022 15:21

That makes it a lot easier. Is the volume too low if you drive earphones directly from the two RCA sockets? Have you tried that yet?

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wellygary

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#2923990 8-Jun-2022 15:23

geekIT:

Sorry guys, forgot to say that this is for better sound while watching TV. The set has two unused RCA output sockets.

What's your budget?

https://www.listeningpost.co.nz/products/headphones/amplifiers-amps/ifi-audio-nano-ican-headphone-amplifier-__I.151778__C.27432__N.27756

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#2924002 8-Jun-2022 15:58

I wouldn't worry about high-priced headphone amps. There are many potential solutions but you don't provide enough information. For example, does the TV support Bluetooth? Wireless headphones might be the ideal solution here and adequate ones (also non-Bluetooth for older devices) can be had for under a hundred dollars.

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nitro

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#2924007 8-Jun-2022 16:08

Rikkitic:

That makes it a lot easier. Is the volume too low if you drive earphones directly from the two RCA sockets? Have you tried that yet?

no point trying that. of course they will be. line-level output is not amplified, and by extension also does not have volume control.

the question i'd ask is - does the tv not have a headphone out port? i can't remember a tv i've had in the last 20+ years that didn't have a headphone port.

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#2924010 8-Jun-2022 16:23

If it still has RCA, it's potentially a bit older than many are assuming?. It's also not clear if it is an input - which would be more common, than output.

I made a travel soap box holding amp back in the day that was RCA in with a POT control. And line switch to choose if I wanted to listed to the tv or the computer audio while sitting at the desk. Good old DSE home kits. Those days are gone

Rikkitic

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#2924012 8-Jun-2022 16:38

nitro:

no point trying that. of course they will be. line-level output is not amplified, and by extension also does not have volume control.

the question i'd ask is - does the tv not have a headphone out port? i can't remember a tv i've had in the last 20+ years that didn't have a headphone port.

It is worth trying. It gives a baseline to go forward from. If he can't hear anything, that isn't the same as being able to make out some words but not all of them. My hearing is diminishing with age, but headphones make things clearer, even at low volume levels. Having an idea of how bad the problem is provides focus for solutions worth considering.

Apart from that, I have a Panasonic TV without any dedicated headphones port. What it has are component output jacks, including RCA audio output, just like the post here.

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gareth41

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#2924017 8-Jun-2022 16:58

You could quite easily build you own from components costing less than $20 - all available from Jaycar.

Use a couple opamp's - a TL072 will do (2 op amps in a 4 pin DIP package) and just configure it as an inverting amplifier. Use 2u2 coupling capacitors on the input and output which will negate the need for a dual rail supply. Bias the input with 2x 10K resistors. Use a 10k pot in the feedback paths of the opamps to adjust volume. Solder the whole thing on a small piece of veroboard and mount in plastic box

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#2924021 8-Jun-2022 17:11

gareth41:

You could quite easily build you own from components costing less than $20 - all available from Jaycar.

Use a couple opamp's - a TL072 will do (2 op amps in a 4 pin DIP package) and just configure it as an inverting amplifier. Use 2u2 coupling capacitors on the input and output which will negate the need for a dual rail supply. Bias the input with 2x 10K resistors. Use a 10k pot in the feedback paths of the opamps to adjust volume. Solder the whole thing on a small piece of veroboard and mount in plastic box

Yep. There are kits on Aliexpress that do this for less than a dollar. But maybe this is not exactly what is being sought.

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geekIT

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#2924031 8-Jun-2022 17:46

Guys, thanks for your inputs. I've just found out more about my mate's entertainment setup. The TV is a 4-yr old TCL55C2US and it does NOT have RCA out. What it DOES have is Optical out and the optical cable is connected to his Sony receiver, a DA1200ES about 12 years old. His hearing isn't great either, so when watching TV he listens to the receiver's output through his wired Sony MDR 7506 headphones. His wife has no hearing problem so she listens normally.

The problem has arisen because his wife's elderly aunt has moved in with them (permanently, I think) Her hearing is quite duff, and she has hearing aids, but finds them uncomfortable. So my mate wondered if they could set up a separate small amp for her sole use, that would work independently of his receiver.

Ergo, while the TV also has an unused headphone jack, I would expect that the jack's output would either be dependent on the TV's volume level, or even cut out altogether if headphones are connected. I'll test this tomorrow.

One thing that might work, is to split the optical out signal and route it to a small amp, which more or less brings me back to my original query.

What do you think?

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Rikkitic

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#2924038 8-Jun-2022 18:12

geekIT:

What do you think?

You still don't mention a budget but that TV has Bluetooth so the simplest solution would be to buy the aunt Bluetooth headphones. Wireless so she can move around freely and it doesn't matter where she sits. Already in the TV so nothing has to be installed, just set up. She can turn them up as loud as she likes. You can find something suitable for under a hundred dollars. Much easier than faffing around with splitters, connectors, adapters, wires, etc.

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Oblivian

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#2924044 8-Jun-2022 18:31

Changing output to Bluetooth tends to also turn off other outputs.

So he will be in the same spot. And noone else will be watching anything.

Will need to send them off to sort it with someone locally rather than going 3rd hand back n forth.
Far as I can tell with what we have to go off is there is no simple solution for parallel use away from a middleware product to tap into the soundbar output while still passing it through.

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