Can I get unamplified audio from onboard soundcard?

[AndyGroom]

Hi,

My motherboard has 3 audio sockets labelled Mic, Line Out and Line In.

I want to connect the computer to an amplifier, however the Line Out socket is amplified and is designed for headphones or non-amplified speakers.

I can't find a jumper or BIOS setting to turn the socket into a proper unamplified Line Out - am I missing something or is there a way to do it? At worst, is there a connector I can buy to go between the computer and the amp to alter the signal to make it unamplified?

If it makes any difference the motherboard is an Asus A7V8MX-SE.

Thanks

- Andy
___________________________________________________________________
If you think nobody cares you're alive, try missing a couple of mortgage payments

 

[ski]

'Line level' voltage is unamplified.
Hence, you should be able connect the 'line out' port on your MB to a 'line in' port on the amplifier, which is normally used for connecting a CD player, VCR, cassette player, etc.

 

[dakota81]

Sound cards are actually more desined to be hooked up to externally amplified equipment than non-amplified speakers. Regardless, it's been a long time since I've seen separate speaker and line-out ports on a sound card, that's just not the way they're built anymore.

I would suggest just keeping the volume level low on the computer if you're that concerned about the amplifier not being able to optimally handle the incoming signal.

 

[AndyGroom]

Although the connector is labelled Line-Out it isn't what I would class a line out (ie. unamplified) signal. If I plug headphones into it then I can hear the audio, which would be impossible if it really was a line out signal.

I've tried keeping the volume at next to nothing but the Amp kicks in something to stop it blowing as soon as the audio starts so it's obviously expecting a completely unamplified signal.


- Andy
___________________________________________________________________
If you think nobody cares you're alive, try missing a couple of mortgage payments

 

[ski]

Check with Radio Shack for an attenuator to reduce the line out voltage.

 

[jurgen36]

All modern ATX motherbords have the same system if they use build in sound or use sound cards. The center connector is not speaker out but as it say's line out. This means the output impedance is optimised for a 500 ohm load. Sure a normal speaker will have some volume, headphones will have sufficient volume to listen "BUT" you could dammage your sound system using it that way, it looks almost like a dead short with a normal speaker (only 2-8 ohms). For sufficient volume you need amplifiers. This is the way the system is designed. Regards

Jurgen

 

[confusedlady]

So, if you wanted the PC's sound to go into an amp with other stereo equipment it's possible? Not a separate amp for the PC sound? From motherboard (line out) to the amp?

I'm hardware impaired, so bear with me!

TIA,
Melissa

 

[norty303]

I'm sorry, but are you saying that this IS or IS NOT a line level output because as far as all of my equipment is concerned I get a line level comparable to all of my other music making equipment, from the master outs of my mixer to the outs of my synths.

 

[AndyGroom]

Let me say I'm not an expert in ohms, impedance and all that stuff. All I know is that when I play audio out of the Line Out port on the motherboard and try to feed it into an amplifier, the amp gives a little internal click and it's goodnight Vienna until you turn it off and back on again.

Similarly, if I plug headphones or unamplified speakers into the Line Out port then I can hear the music.

To me this means the port isn't a Line Out at all but more of an Audio Out. It might be the case that if you plug it into a cheapo amplifier or a set of amplified speakers designed for a computer then it's fine because they can amplify an already amplified signal, however I'm using a Yamaha DSP-A2 amp which is probably a bit more finickety about the signal.


- Andy
___________________________________________________________________
If you think nobody cares you're alive, try missing a couple of mortgage payments

 

[norty303]

I run multiple outputs from my soundcard (Audigy) One goes into a pair of Alesis M1 Active studio monitors, the other goes into a pro quality Pioneer DJM-600 mixer. The output from the Audigy (on max volume on the PC) gives exactly the same output as a Pioneer CDJ100 (Pro CD player) on the same gain settings on the mixer (3db sensitivity on the meters) If I plug a line level (cd player) into the monitors I get the same volume (gauged by ear I'm afraid, no dB meter!! ) from that source as the soundcard.

I'm going to test this when i'm able to but I'm pretty sure that a line level is enough to power headphones. Just need to make up an RCA to jack adaptor.

*time passes*

I'm getting the impression after looking around that the socket output depends on the impedence of whats plugged into it (e.g. headphones or into a line input) That's not to say it's intelligent or 'switching' or anything, just the way it's spec'd.

AndyGroom... I'm wondering if you are able to pass the signal to another device first (line-in) then out of a line-out into the amp, does it do the same thing? Might help to see where the problem is.

 

[ski]

Andy,
Make sure that you're not connecting the sound card's line out to the amp's phono line in. It will not be able to handle the voltage.

 

[fenix]

my 2cents as there still seems to be unanswered questions in this thread and I'm curious as to what is going on.

To Andy, I'm trying to understand your audio setup. Are you saying that you are going directly to an amplifier input without a mixing board ? Is it a tuner/amplifier? Or a stand alone amplifier that is usually used with a mixing board ?

As someone asked, exactly what input are you going into and how is it labeled.

Are you saying that your output from the card drives headphones, but it overdrives a normal audio line-in and you get the popping noises ?

I slightly disagree with ski about a line out having no voltgage. I believe that it needs a small amount of voltage to carry the signal, but much less than to drive a headphone or a set of speakers. As an example, many portable cd players have a head phone out that goes through the volume switch for level adjustment, and a pure line out like most modern sound cards have, with a fixed
level. This is referred to as an audio out, or just line out if this helps melisa's ?.

Im' thinking that this might be a perculularity of the sound card being used, which I'm surprised hasn't been mentioned what kind it is yet. Can the sound card be defective ?

One thing I'd like to know, is what happens when you plug another device into the same place that you are plugging the line out into, such as a stand alone cd player's line out. Or on the amplified side of this matter, have you tried taking a line out from a stereo headphone jack on a tv or a boombox ? Does it react the same ?

Switch and swap and see if the problem follows or doesn't follow ....hope to hear back about this.

 

[AndyGroom]

My setup is pretty simple, I've got a new PC with an Asus motherboard - no additional cards of any sort plugged into it - and the motherboard has onboard video and audio.

The audio port on the motherboard has 3 x 3.5mm sockets - Mic, Line In and Line Out.

From Line Out on the motherboard goes a cable with a 3.5mm stereo jack on one end and 2 phono plugs on the other end, into the Aux In input on my amplifier. There's no mixing board inbetween.

If I plug the Line Out from my hifi CD player into the Aux In on the amp I get CD audio perfectly. From the motherboard I get squat.

If I plug headphones into the Line Out on the motherboard I can hear audio.

I hope this clarifies the setup, all suggestions are welcome! If all else fails I'll try and get digital audio out of the motherboard and use a digital input on the amp.


- Andy
___________________________________________________________________
If you think nobody cares you're alive, try missing a couple of mortgage payments

 

[G0AOZ]

I don't know the exact audio chipset you've got on that mobo, but I'd say your problems can be put down to a serious impedance mismatch. The Asus A7V8X uses an ALC650 chipset which quotes LINE OUT as 50mW at 20 ohm - I'd say your A7V8MX is likely to be very similar...

Your amplifier input is going to be an impedance of around 50Kohms if not considerably more, so you either need to use some type of mixer unit or a properly designed impedance matching unit.


ROGER.

 

[ski]

I slightly disagree with ski about a line out having no voltgage"

fenix,
Actually, I stated that "line level voltage is unamplified", meaning that its voltage level is very small, and it can normally be input into 'line in' port for amplification.
On the other side of the coin is amplified voltage which is normally connected to high voltage devices, like speakers.

 

[AndyGroom]

Thanks G0AOZ,

I'll have a hunt round the local gadget shop and see if I can find something to equalise the impedance between the computer and the amp.


- Andy
___________________________________________________________________
If you think nobody cares you're alive, try missing a couple of mortgage payments

 

[fenix]

one quick reply due to lack of time, but can it be that you have a DIGITAL output and are trying to mate it up to an analog input ? I suspect this might be the case after reading the latest psot.

 

[ceh4702]

Creative makes a kind of mixer box that comes with a digital sound card and an input box that is pretty impressive. But Generally I think most things are designed to get music into the computer not vice versa. I was wondering if you hooked a line up to the back of a CD Drive if that would be an unamplified Line-Out.

Anyway the device I was looking at is a Creative E-MU 1820:

http://www6.tomshardware.com/consumer/20040611/index.html

This is a home studio mixer card not a regular sound card.



If you do not like my post feel free to point out your opinion or my errors.

 

[G0AOZ]

Fenix it's a thought, but I'm pretty sure you'll find this board follows the others in the A7V8xx series which has an analogue 3.5mm LINE OUT jack on the rear edge of the mobo. Digital output is available from the SPDIF header mounted directly on the mobo at the back of and between the second and third PCI slots.


Andy, I have found some info re the chipset on your mobo. It's an ANALOG DEVICES Codec AD1980. Relevant spec for LINE_OUT as follows:

Full-scale Output voltage = 1V rms or 2.83V p-p
Output impedance = 800 Ohms
Output capacitance = 15pF
External load capitance = 100pF
External Load Impedance = 32 Ohms

I believe the first and last on this list are the most important parameters you need to consider when matching to your amplifier.


ROGER.

 

[micker377]

Simple - get a cheap sound card and dis-able onboard sound. This way you can even set-up 5.1 or better surround sound.