Expected performance from DAC in a modern TV ?

[bothu]

Does anyone know what kind of DAC there is in a modern TV ?
And what performance I can expect from it.
For the moment I am using the analog output from the TV to my analog stereo system.
The TV is a SONY 65XH9505. ( 3 month old )

 

[Ron Texas]

Does anyone know what kind of DAC there is in a modern TV ?
And what performance I can expect from it.
For the moment I am using the analog output from the TV to my analog stereo system.
The TV is a SONY 65XH9505. ( 3 month old )

Your TV should have a digital out via Toslink. To take advantage of it you need to have some way to control volume on your DAC and also EQ.

 

[Inner Space]

Does anyone know what kind of DAC there is in a modern TV ?
And what performance I can expect from it.
For the moment I am using the analog output from the TV to my analog stereo system.
The TV is a SONY 65XH9505. ( 3 month old )

I do the same thing with my new-ish Sony - the "headphone" out to RCA in on a Benchmark preamp. I did a level-matched but sighted comparison with the optical out to a Benchmark DAC3, and could detect no audible difference at all.

I imagine the internal DAC is a competent little chip, like the ones in headphone dongles. Works for me.

 

[Lambda]

For the moment I am using the analog output from the TV to my analog stereo system.

And is there a problem?
if not your probably fine.

 

[Jimbob54]

I suspect the 3.5mm jacks on TVs as headphone amps under any kind of load might be terrible- would imagine they are good enough into an external amp etc. Ive heard some say some modern TVs can feed a dongle DAC via the USB sockets which might be a cheap option if you dont like the 3.5mm jack option

 

[3125b]

Alright, so I measured it. What a pain.

Anyway, my TV is a LG OLED55C9 that was fed by a Windows PC using HDMI and measured via RME ADI-2 Pro FS using REW 5.20 on a laptop. No ground loops were present.

The results were about what I suspected. Not too good but not too critical in practice either, although it does just about everything wrong that it can do wrong.
We have clipping at full volume, rather high noise floor and high output impedance.

Measurements without a load:

At full volume there is heavy clipping. At 75 volume (Windows volume control) there is no clipping but the SNR is limited to 73dB. The performance is best at about 55 volume with a SINAD of 79dB. Weirdly there is a power supply spike at 60Hz when the mains frequency here in Europe is 50Hz. Never seen that before.

Under load that output voltage collapses:

The calculated output impedance is a whopping 149 ohms wich is very high. This output would work better with high impedance headphones. 50mV SINAD with 33R load is 67dB wich is rather poor as well and might be audibly problematic.

All in all not a very good showing for a 1500€ TV. But then again, not many people would use the internal DAC/amp so it's probably just fed from the amp for the internal speakers through a resistor.

 

[Jimbob54]

Alright, so I measured it. What a pain.

Anyway, my TV is a LG OLED55C9 that was fed by a Windows PC using HDMI and measured via RME ADI-2 Pro FS using REW 5.20 on a laptop. No ground loops were present.

The results were about what I suspected. Not too good but not too critical in practice either, although it does just about everything wrong that it can do wrong.
We have clipping at full volume, rather high noise floor and high output impedance.

Measurements without a load:
View attachment 166184View attachment 166185View attachment 166186
At full volume there is heavy clipping. At 75 volume (Windows volume control) there is no clipping but the SNR is limited to 73dB. The performance is best at about 55 volume with a SINAD of 79dB. Weirdly there is a power supply spike at 60Hz when the mains frequency here in Europe is 50Hz. Never seen that before.

Und load that output voltage collapses:
View attachment 166187View attachment 166188
The calculated output impedance is a whopping 149 ohms wich is very high. This output would work better with high impedance headphones. 50mV SINAD with 33R load is 67dB wich is rather poor as well and might be audibly problematic.

All in all not a very good showing for a 1500€ TV. But then again, not many people would use the internal DAC/amp so it's probably just fed from the amp for the internal speakers through a resistor.

Good work- pretty much as expected- terrible as a driver for headphones, definitely good enough for casual music listening through your stereo if you dont want to fire up the PC , dont have the ability to cast / spotify connect to your DAC or have no toslink cable into your DAC etc etc

EDIT- absolute heresy but a complete system including EQ might be Tidal via UAPP on an Android phone with the Tonesbuster EQ plugin for a couple of $$ casting (with EQ since v6) to an Android TV, 3.5mm jack to phono connectors on decent powered speakers. No other boxes, minimal cables, bingo.

 

[abdo123]

Alright, so I measured it. What a pain.

Anyway, my TV is a LG OLED55C9 that was fed by a Windows PC using HDMI and measured via RME ADI-2 Pro FS using REW 5.20 on a laptop. No ground loops were present.

The results were about what I suspected. Not too good but not too critical in practice either, although it does just about everything wrong that it can do wrong.
We have clipping at full volume, rather high noise floor and high output impedance.

Measurements without a load:
View attachment 166184View attachment 166185View attachment 166186
At full volume there is heavy clipping. At 75 volume (Windows volume control) there is no clipping but the SNR is limited to 73dB. The performance is best at about 55 volume with a SINAD of 79dB. Weirdly there is a power supply spike at 60Hz when the mains frequency here in Europe is 50Hz. Never seen that before.

Und load that output voltage collapses:
View attachment 166187View attachment 166188
The calculated output impedance is a whopping 149 ohms wich is very high. This output would work better with high impedance headphones. 50mV SINAD with 33R load is 67dB wich is rather poor as well and might be audibly problematic.

All in all not a very good showing for a 1500€ TV. But then again, not many people would use the internal DAC/amp so it's probably just fed from the amp for the internal speakers through a resistor.

22uV noise floor is not too shabby at all! ~100dB S/N.

I might ditch using an external DAC after all.

 

[3125b]

22uV noise floor is not too shabby at all!

Loaded because of the high Zout. Unloaded it's worse, best case 79dB SINAD with both scenarios.
But I read that LG TVs have particularly bad aux outputs, don't have a different TV to verify that though.

That TV is used with a Sanskrit MK II and a pair of Focal Alpha 65 btw. Works well via Toslink.

 

[bothu]

Alright, so I measured it. What a pain.

Anyway, my TV is a LG OLED55C9 that was fed by a Windows PC using HDMI and measured via RME ADI-2 Pro FS using REW 5.20 on a laptop. No ground loops were present.

The results were about what I suspected. Not too good but not too critical in practice either, although it does just about everything wrong that it can do wrong.
We have clipping at full volume, rather high noise floor and high output impedance.

Measurements without a load:
View attachment 166184View attachment 166185View attachment 166186
At full volume there is heavy clipping. At 75 volume (Windows volume control) there is no clipping but the SNR is limited to 73dB. The performance is best at about 55 volume with a SINAD of 79dB. Weirdly there is a power supply spike at 60Hz when the mains frequency here in Europe is 50Hz. Never seen that before.

Under load that output voltage collapses:
View attachment 166187View attachment 166188
The calculated output impedance is a whopping 149 ohms wich is very high. This output would work better with high impedance headphones. 50mV SINAD with 33R load is 67dB wich is rather poor as well and might be audibly problematic.

All in all not a very good showing for a 1500€ TV. But then again, not many people would use the internal DAC/amp so it's probably just fed from the amp for the internal speakers through a resistor.

Excellent and ambitious work 3125b !
ASR are the right forum to join, with competent and helpful members.

I can relax, the performance of the TV DAC is good enough for normal listening needs.
I have no AVR-reseiver and I do not see any reason to have one. We are fine with movies in 2 channels at home.
In the future I will bye an external DAC for my stereo system.

Thank you all for the help.