Sound card input voltage range?

[J.R.Freeman]

Good morning all,

Would someone be able to point me to a document showing the acceptable voltage levels that can be applied to the 'audio in' port of a standard PC sound card?

Wikipedia lists this value at 0.447 volt peak. Should I trust this? I would hate to blow things up and find out they meant peak-to-peak.

Thanks,

Jim

[ashok]

No ,some cards, particularly pro-audio cards, can take up to +4dBm I think. Many other good cards can take up to 1 volt rms.
Check the card manufacturers web site for a spec sheet on the card you want to look at. Inexpensive cards will have a lower input voltage limit I guess.

[J.R.Freeman]

Hi Ashok,

Thank you for your comments. That's a good idea about finding the data sheet for my sound card. I'm planning a little field experiment, and I'll be using my girlfriend's Dell laptop, so it would be in my best interest not to explode it :P

Jim

[ashok]

You are going to use your girl friends laptop ?
Can she get violent ?.............after you wreck it !

But most laptop's have crappy inbuilt sound and I have hardly seen any specs on them. I think most can handle much less than 1 volt input and some have only mic input ( no line in )! So better check it carefully. Stick to 0.5 Vrms or less into the 'line in' input. Don't use it if it's only mic input !

Most laptop users use an external sound card ( USB audio ) like the M-Audio Transit for measurement/recording purposes. Even that has limited input I think. Might be 0.775 V or so. Check it !

[Artie]

I believe most soundcards, (or any audio input for that matter), have a pretty healthy overload spec. You can "clip" the input, but it isn't likely that you would cause any physical damage even with several volts in.

On the other hand, if I'm way off base here, I hope someone will let me know.

[ashok]

I am not sure but looks like anything above 4 volts peak ( 2.8 V rms) for usual sound cards is not recommended. This would be heavily clipped in any case. You could always test any used discarded old generation card till it breaks !

Does gross overloading degenerate the input devices in a sound card ? Resulting in a noisier card ?

[dangus]

Run scope software, connect a signal generator, and turn up the volume until the waveform clips. Play with the recording level adjustment and see how it affects things.