Sound Card Output to TV/Stereo

[nicenice]

I have AC97 sound integrated on monthboard (K7S5A). I tried to connect lineout to TV or HiFi stereo aux input to watch video on TV. I could hear the sound but the volume was very low. I adjusted the volume level in Windows to the highest, but the output was still low. If I higher the stereo or TV volume, I got big humming. However, if I connect the lineout to regular amp PC speakers, the sound is fine. What's the problem? Will a new sound card be any help on this?

 

[G0AOZ]

Assuming you have the correct connections to the TV input, the hum suggests that there might be an earthing problem of some sort. You need to check that there's no potential difference between the earth connection on the PC and that of the TV. Also, the output impedance of the AC97 soundcard will probably be low, i.e. 8 to 16 ohms, whereas the AUX input to a TV or Hi-Fi system will invariably be high impedance, e.g. 50K, 100K etc. A mismatch of this sort can cause significant loss of volume, and at worst, distortion of the audio signal. The fact that it works ok into your amplified PC speakers, shows that the speaker input is matched to accept the low impedance output of your soundcard. Another point worth making here is that you should be using screened twin audio lead between the PC and the TV, in order to reduce mains hum pickup and indeed any other unwanted signals that the TV might be radiating!

As to whether adding a new soundcard will solve the problem, you would need to find a card that offered a high impedance line output. Some older soundcards used to have 4 sockets:- microphone input, line input, loudspeaker output and line output.

Good luck.


ROGER - G0AOZ.

 

[jdunderhill]

Very good post G0AOZ

I was thinking, you can get a similar humming noise if you dont connect the Jack right into the socket or if the wire is bent on the flexible part of the Jack socket

I can only go as far to suggest, making double sure the jack is right in the socket

The line out cable isn't bad and that the connections are pushe firmly into the back of your stereo/TV on BOTH channels

Beleive me I've had these type of problems before and that how i resolved em!!

Good luck

Jamie

 

[nicenice]

Thank you all for the reply and help.

Here is more details on the issue:
I used to watch video on PC. I connected lineout (There is no speaker out on motherboard) to amp PC speakers (YAMAHA). Everything was good, sound quality was ok and volume level was high enough.

Then, I wanted to watch video on TV. I connected TV video out to TV and sound lineout to TV audio input (splitter cable from stereo to two RCAs). Video was fine, but the sound volume was very low, I could still hear it though.
I thought something maybe wrong with TV audio input. So I connected the lineout to my HiFi AUX input instead. I got exactly the same problem: volume was very low.

I'm thinking of getting a sound card. How to find a card that offered a high impedance line output? I looked at a couple of cards. I did not see anything like this listed in their spec.

 

[ANFPS26]

Can't you listen to the sound on the PC speakers and watch the TV?

Jim

 

[nicenice]

Of course I can. I just want to make things better.

 

[TekTippy4U]

When you use the TV audio input/or the Hi Fi Aux....you need to tell the TV(through menu) to "read that PORT" so to speak......you even probably have an AV INPUT choise on your remote....
The jacks on my vcr=
rear audio and video is LINE 1
front inputs are LINE 2

TT4U