connection problems

[raymo]

I am an ancient digital dunce with a problem, and am hoping that someone can help me.
My wife and I have Sennheiser 120 analogue wireless headphones that we
used with our non smart TV.
I can find no way of connecting them to my new smart TV. The only suitable
outlet is digital optical. I bought a digital to analogue converter which I connected according to the instructions, but only get static on my phones.
In Settings the sub heading Headphones is greyed out. If you click on it, it
says this service is not available. I don't want to fork out for bluetooth phones only to find that they won't work either.
Any ideas? any suggestions appreciated.
raymo

[floyd_2 (Dean)]

Whilst I can't answer your question, I know that others here will easily cover that off. I thought I might just add that BT headphones might introduce some latency into your audio. It's not a problem when you're purely listening to audio, but when you're watching TV it's possible that there might be a lip sync issue with BT audio. Something to consider if you head down that path anyway.

[croweater (Richard)]

Hi Raymo. On my smart tv you go to settings. Then select "sound". Then "sound output".
Then "audio/optical" Hope that helps.
Cheers, Richard

[raymo]

Thanks D and R.
When I set the sound output to Set For Headphones it says this service is not available. I don't understand why my digital to analogue converter has not fixed the problem.
raymo

[croweater (Richard)]

Is there an option to set sound output to optical ? Not for headphones but optical out.

[raymo]

No; Just different sound modules which you can select, and make selections within them.
raymo

[ronson]

Hi Raymo,
It may help others provide some ideas/guidance, if you let us know:
1. The make and model of the TV;
2. The make and model of the digital to analogue converter;
3. What analogue interface(s) the headphones transmitter has e.g., RCA, 3.5 plug etc.

[doug mc]

I just in the past couple of weeks bought a new Akai smart tv. When purchasing I assumed it would have a headphone outlet, but no. Only optical audio out only. I ended up purchasing an audio optical out splitter cable so I could connect both my sound bar and headphone dac. The dac I bought from Amazon. It's a Fosi Audio DAC-04. It has both optical audio and rca inputs with headphone out. I use Phillips X2HR headphones with it but it's a wired headphone. With this set-up I don't notice audio lag with the headphones but there is audio lag with the sound bar. I turn down the tv volume when using the sound bar.

[raymo]

Thanks for the replies.
My LG DVD player is RCA only, so I bought an RCA to HDMI converter and
a digital to analogue converter for the phones, on ebay. The DVD works fine.
When the headphones didn't work, I tried the D to A converter on my other TV [TCL] and it worked o.k. which makes me think the problem is within the TV; either there is something somewhere that I need to select or activate,
or the TV just is not sending audio signal to the converter for some weird reason. In Settings- Sound- the headphones selection is greyed out saying
"this service is unavailable". The TV is a Hisense 65U7KAU Oh, and the
Sennheiser headphones connection is RCA only. The Chinese converters have no company name on them. I do get static through the phones which changes as you rotate the tuning wheel on the phones, just no trace of audio signal, could it be that wavelengths covered are not compatible with this particular brand of TV, although that seems bizarre. The converter is USB powered, and the power light illuminates when the TV is turned on.
raymo

[sharkbite]

Hi Raymo...

The hisense website does not appear to have a manual for your tv, but i googled one up on a 3rd party website.

the TV does not have a physical headphone output - if this is correct, that explains why the option is greyed out.

What you need to do is:
1.) Connect the d/a converter input to the digital output of the tv
2.) connect your headphone RCA inputs to the RCA outputs of the D/A converter,
3.) set your TV to output the audio to the digital output.

If this does not work - the d/a converter may not be compatible with the TV.(something i learned the hard way with an old LGtv)

[raymo]

Thanks for the reply. I connected the converter as you described.
In Settings-Sound there is not a command to utilise the digital optical
out connection, so I have to assume that it is permanently active.
How the heck would I go about finding a compatible converter?
Raymo

[sharkbite]

Hi Raymo...

got this from the manual i found...here:

https://www.hisense-usa.com/support/...oogle-tv-65u7k

Page 36:

Audio Output

to Select Speakers

Press the "settings"button on your remote control to select Settings > Display & Sound > Audio Output > Audio
Output Selection.
Select the speakers which you want to use.

*settings button is the one that looks like a geared wheel

[raymo]

Thanks so much for your efforts. None of the speaker choices such as ARC or
bluetooth made any difference to the static I receive through my headphones.
Digital optical is greyed out, so I can't select it.
raymo

[ronson]

According to this discussion, you might need to use a DAC like this one.

Though there is no guarantee it will work.

Have you reached out to Hisense support to see if they have any recommendations?

[sharkbite]

"Digital optical is greyed out, so I can't select it."

This is just weird - i'd also go back to hisense on this one...

Another thing just struck me - are you using the TV USB port to power the DAC?

Sometimes these ports dont really have the snot to power anything more than a usb stick....you could try powering it with a USB phone charger to see if thats it?

The headphones themselves are basically an FM radio, and the sennheiser base station is just an FM transmitter, so the fact that you cant 'tune in' and all you get is static...tells me there is something not right there as well, although you have said that it was working with the other telly, so i cant guess what....

Best of luck with this.

[raymo]

Thanks for your input Ronson. I need to find out the sampling rate of the TV
before spending good money on a DAC that may not fix the problem.
Contacting support is an exercise in futility, just like with many other large organisations, but I guess that I'll have to set up a camp bed by the phone.

Sharkbite, I have now powered the converter with a 2.4amp supply; no joy.
My converter covers 4 sampling rates 32,44,96, and148khz, but I have to somehow ascertain the TV's requirement.
raymo

[Shiraz (Ray)]

just a thought, can you see the red light output from the optical cable when it is just plugged into the TV? that would at least let you know if the set was outputting a signal. cheers Ray

[raymo]

Hi Shiraz, I have just received the worst possible news, so the TV problem will have to go on the shelf, but yes the red light is showing.
raymo

[Shiraz (Ray)]

Genuinely sorry to hear that. Ray

[raymo]

Thanks Ray, appreciate it.
raymo