• Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

Speaker wiring

NotAClue

New Member
HI folks...just joined your forums which I didn't know existed but glad I found it!
Anyway, I have a fairly simple question, and that is: I have a 55" Sharp TV and I'm trying to be able to output audio for a bluetooth transmitter. I can come from my cable box and that works fine, until I want to watch Amazon prime, or anything else that's not coming through the box. Plugging a 3.5 jack into the headphones mutes the TV speakers, so that won't work. There is a digital audio out which I could run through an analog converter, but I'm not sure about the Toslink muting the speakers. Says nothing about it in the specs, but does mention the headphone jack WILL mute tv, so the Toslink is a maybe.
I pulled the back off the tv, and was going to add a 3.5mm female bulkhead jack but see a total of four speaker leads. Left and right + and -, and wasn't sure about tying the negative leads together. Don't want to "let the smoke out of the box", and my wife's dying to hit me with "told you so".
Any thoughts on this?
 

Nigel Goodwin

Super Moderator
Most Helpful Member
TOSLINK doesn't mute the sound - it's a completely one way system, and doesn't even know if anything is connected or not.

I can't comment specifically on the TV, as you don;t even mention what country you're in, and Sharp stopped making TV's a number of years ago, selling the use of the name to various different cheap manufacturers - and even prior to that, hadn't made many TV's for many years anyway.

However, it's VERY common for TV's to use bridged audio output stages, so you MUST NOT join any of the wires together - or you will indeed 'let the magic smoke out'.

I would suggest you get the TOSLINK converter, which should work fine.
 

Les Jones

Well-Known Member
Most Helpful Member
I suspect that the amplifier is a bridged design (And probably class D.) so none of the wires to the speaker can be connected to ground. I have an LG TV with a bridged class D output. I did try getting the output between ground and one of the speaker leads but there was a lot of mains hum on the output. As you say that you have a headphone socket you may be able to tap of the audio from some of the connections on the socket. That way you would not operate the contacts on the socket that mute the speakers. I suggest that you try to find a schematic online to see if there is a better way.

Les.
 

NotAClue

New Member
Gentlemen: I appreciate the quick feedback and you've reinforced what I was thinking. I've seen D to A converters on Amazon for about $10 that will take a Toslink input, and 3.5mm or RCA out, so I think that will be what I"ll try. Thanks!
 
Last edited:

KeepItSimpleStupid

Well-Known Member
Most Helpful Member
I would expect the mute control to mute TOSLINK. Headphones are generally for "private listening", so the MO is appropriate.

TOSLINK is pretty much an optical connector, not a standard output. Make sure you A/D is compatable. to what you can set the connector too. PCM left right is common, but there is also dolby digital AC3. This would be a 5.1 audio source that would be for an ATSC TV (Antenna US). Sample rates can also be different.

HDMI can also have a digital audio signal on it.

This https://www.bhphotovideo.com/c/prod..._500081_digital_audio_converter.html/overview does downmixing of Dolby Digital and PCM. Downmixing means it takes 5.1 and creates 2 channel out.
 

Nigel Goodwin

Super Moderator
Most Helpful Member
I would expect the mute control to mute TOSLINK. Headphones are generally for "private listening", so the MO is appropriate.
There's always a chance that you 'might' find a set that does, but it would be unusual and rare - there's no need (or want) to mute the digital audio out - and it's along way before the audio muting circuits.

TOSLINK is pretty much an optical connector, not a standard output.
I don't quite follow you?, it's a standard connector and output for optical audio.

The signal itself is identical to coaxial digital audio, and is simply a coaxial audio socket wired to an LED - and at the other end an optical receiver wired to the coaxial input. A lot of DVD players etc. have PCB connections for both, with either one, or even both, sockets fitted.
 

NotAClue

New Member
Picked up a D to A converter and it works great! Headphone output goes into a bluetooth transmitter to my wireless earbuds. There were some sync issues but the TV provides a sync setting for that output which is designed to sync an external speaker (sound bar, etc) with the video so that I was able to correct them. Thanks again for all of the feedback and advise.

DtoA.jpg
 

eTech

Active Member
HI folks...just joined your forums which I didn't know existed but glad I found it!
Anyway, I have a fairly simple question, and that is: I have a 55" Sharp TV and I'm trying to be able to output audio for a bluetooth transmitter. I can come from my cable box and that works fine, until I want to watch Amazon prime, or anything else that's not coming through the box. Plugging a 3.5 jack into the headphones mutes the TV speakers, so that won't work. There is a digital audio out which I could run through an analog converter, but I'm not sure about the Toslink muting the speakers. Says nothing about it in the specs, but does mention the headphone jack WILL mute tv, so the Toslink is a maybe.
I pulled the back off the tv, and was going to add a 3.5mm female bulkhead jack but see a total of four speaker leads. Left and right + and -, and wasn't sure about tying the negative leads together. Don't want to "let the smoke out of the box", and my wife's dying to hit me with "told you so".
Any thoughts on this?
can you provide the model number of your TV?
 

NotAClue

New Member
can you provide the model number of your TV?
It's a Sharp (Hisense) LC-55P6000U
I found the solution to my issue by using a D to A converter. Toslink into converter, the converter output 3.5mm out to a bluetooth transmitter to my wireless earbuds. Muting TV volume does not mute the Toslink output, and there's an audio setting in the setup which allows one to sync audio and video to correct latency issues.
 

Latest threads

EE World Online Articles

Loading
Top