[MystroVictim]

Like many others I have a Flat Screen HDTV that only has a 5.1 optical output and I would like to drive an old stereo system with Line Level 2 ch analog audio.


I have tried the infamous Gefen DAC with no joy.


Has anyone tried the Hall Research DAC-51?


Has anyone found a reliable 5.1 Optical to 2 ch analog converter?


TIA

 

[ctdish]

It might be possible to set the TV to output two channel digital and get the Genfen to work. You need to look through the TV's menus relating to the digital sound output. A lot of info on this subject here:
http://www.avsforum.com/t/1350879/connecting-headphones-to-a-tv-with-digital-audio-out/0_100

John

 

[Ratman]



Quote:
Originally Posted by MystroVictim  /t/1523647/5-1-optical-audio-to-2ch-analog-audio#post_24512751


I have tried the infamous Gefen DAC with no joy.

Which one?

 

[MystroVictim]

Gefen GTV-DD-2-AA


LG tv 42LE5350 no setting for 2 channel I can find.

 

[holl_ands]

HDTV should have a Digital Audio Menu Setting to select either DD5.1 or PCM (2-Ch Stereo) for Optical Digital Audio Output.....you probably need PCM for the converter to output Stereo.

 

[MystroVictim]



Quote:
Originally Posted by holl_ands  /t/1523647/5-1-optical-audio-to-2ch-analog-audio#post_24513308


HDTV should have a Digital Audio Menu Setting to select either DD5.1 or PCM (2-Ch Stereo) for Optical Digital Audio Output.....you probably need PCM for the converter to output Stereo.

There is no setting for Digital Audio.

It is permanently 5.1 ch.


That particular Gefen DAC was made for 5.1 but does not work. Tried two of them. Neither functioned. Called co. Worked with Tech on phone.

No joy.

 

[retiredengineer]

The specification shows a headphone output. Can't you use that to output to your stereo?

 

[MystroVictim]

I have tried the headphone jack.

The sound is absolutely flat, like a tabletop clock radio

and the output level is so low you have to turn the volume on the TV to practically the maximum.

These two problems make it unusable.

 

[domino92024]



Quote:
Originally Posted by MystroVictim  /t/1523647/5-1-optical-audio-to-2ch-analog-audio#post_24512751


Like many others I have a Flat Screen HDTV that only has a 5.1 optical output and I would like to drive an old stereo system with Line Level 2 ch analog audio.


I have tried the infamous Gefen DAC with no joy.

You probably tried the wrong one. You need the GTV-DD-2-AA, NOT the GTV-DIGAUD-2-AAUD. The latter only works on PCM digital.

 

[domino92024]



Quote:
Originally Posted by MystroVictim  /t/1523647/5-1-optical-audio-to-2ch-analog-audio#post_24513268


Gefen GTV-DD-2-AA


LG tv 42LE5350 no setting for 2 channel I can find.

Hmmm...odd. I've installed a half dozen or so of the GTV-DD-2-AA converters with no problems. Maybe your TV's DD5.1 isn't quite per Dolby spec. Do you have another DD5.1 source you could try, like a DVD or BD player?

 

[Ratman]

Did you do this?

Quote:
Set the “TV Speaker option - Off” in the

AUDIO menu. (►p.150). See the external audio

equipment instruction manual for operation.

 

[retiredengineer]



Quote:
Originally Posted by MystroVictim  /t/1523647/5-1-optical-audio-to-2ch-analog-audio#post_24514102


I have tried the headphone jack.

The sound is absolutely flat, like a tabletop clock radio

and the output level is so low you have to turn the volume on the TV to practically the maximum.

These two problems make it unusable.

Amazon sells the iBoost 800 preamplifier that solves this problem. If it doesn't work, you can return it.

 

[MystroVictim]



Quote:
Originally Posted by domino92024  /t/1523647/5-1-optical-audio-to-2ch-analog-audio#post_24514510


You probably tried the wrong one. You need the GTV-DD-2-AA, NOT the GTV-DIGAUD-2-AAUD. The latter only works on PCM digital.

I ordered and received two Gefen GTV-DD-2-AA. I never had or tried the other unit you mention.

 

[MystroVictim]



Quote:
Originally Posted by domino92024  /t/1523647/5-1-optical-audio-to-2ch-analog-audio#post_24514520


Hmmm...odd. I've installed a half dozen or so of the GTV-DD-2-AA converters with no problems. Maybe your TV's DD5.1 isn't quite per Dolby spec. Do you have another DD5.1 source you could try, like a DVD or BD player?

I tried it on my cable box optical output and it would not work on that either.

 

[MystroVictim]



Quote:
Originally Posted by Ratman  /t/1523647/5-1-optical-audio-to-2ch-analog-audio#post_24515168


Did you do this?

Honestly, no. The Gefen techs did not make mention of it. And this from the manual seemed to imply that it was optional.


"When connecting with external audio equipment, such

as amplifiers or speakers, you can turn the TV speakers

off in the menu. (►p.150)"


Since it did not work on my cable box either, the belief all around was that they were defective.

 

[MystroVictim]



Quote:
Originally Posted by retiredengineer  /t/1523647/5-1-optical-audio-to-2ch-analog-audio#post_24516824


Amazon sells the iBoost 800 preamplifier that solves this problem. If it doesn't work, you can return it.

I can give it a try, but really the sound quality out of the headphone jack is from the time of Alexander Graham Bell.

Very flat, very tinny, very undesirable.

 

[domino92024]



Quote:
Originally Posted by MystroVictim  /t/1523647/5-1-optical-audio-to-2ch-analog-audio#post_24517686

Quote:
Originally Posted by domino92024  /t/1523647/5-1-optical-audio-to-2ch-analog-audio#post_24514520


Hmmm...odd. I've installed a half dozen or so of the GTV-DD-2-AA converters with no problems. Maybe your TV's DD5.1 isn't quite per Dolby spec. Do you have another DD5.1 source you could try, like a DVD or BD player?

I tried it on my cable box optical output and it would not work on that either.

As long as your +5v PSU is putting out +5v, and you are toggling the input button to the right input (coaxial or optical), I haven't any more suggestions. What LEDs are lit? Is your optical cable good? It sure seems odd that I have installed a half dozen or of the GTV-DD-2-AA converters without failure, but you get 2/2 that don't work.

 

[Ratman]

I find it hard to believe that 2 Gefen boxes were/are bad. Something is being overlooked in audio setup IMHO.

1) are you sure the optical cable is "good"?

2) have you removed the protective caps from the ends of the optical cable?

3) are you sure that the optical cable is properly/fully inserted at each end?

4) are your analog audio cables good?

5) are you sure that the audio input of the stereo system is selected and/or operating properly?

 

[retiredengineer]

Most of the reviews of the DAC I've seen says they fail after a few months. Given the small size of the device and the amount of processing they have to do, I'm guessing they fail from overheating. Is it possible the failed devices are returned and the seller just restocks them to sell again???

 

[Ratman]

You're correct... that's just a guess.