What is Audigy output voltage?

CyberGene

Does anyone know what the audio output voltage for Audigy 1394 is (I suppose it's the same for all of the Audigy I series)? I have bought a Hi-Fi amplifier with its inputs specified as 200mv sensitivity, so I don't want to overload it. When I connect a pair of headphones to the supposed line-out of the soundcard (the swapped front to rear output for that matter) the signal is loud enough for the headphones, so it is probably amplified internally. Here are my questions:

1. What exactly does 200mV input sensitivity on my Hi-Fi amp mean? Is it true that if I use signal which exceeds that voltage, it will cause distortions?

2. Is there a standard value for what is considered line-out signal level (for examples Hi-Fi CD players)?

3. How much is that output level for Audigy and is it bigger than the standard value?

4. If the answers for 2 and 3 are Yes, then is it true that Audigy uses internal amplifier which could eventually bring additional noise/distortions?

5. If yes, how can I set the main volume slider to a value which will be OK for my amplifier? Is there a way to determine what would be the output voltage at certain slider position and what is the optimal one?

I am sorry if my questions are lame. Thank you in advance!

Nappylady

(answer to #1, #2, #3) Almost all gear operates at one of two levels: +4dBu or -10dBV. (The difference between those two levels, contrary to what you might think, is not 14dB. It's only 11.79dB. The mathematics behind this are beyond the scope of this post.) +4 usually means "professional" and -10 usually means "consumer". However, the Audigy is set up for +4 operation.

(#4) The last amplification stage on the soundcard is a line driver, which both sets the output level, and makes the output impedance appropriate for either another amplifier, or headphones. You do not want to bypass this amplifier.

(#5) The best way to check this is to hook up your amplifier to the sound card and to some speakers, and play some loud, clean music very quietly--rock music from the 80's is a good choice, because the levels in the music reach 0dBFS (full-signal, in other words) but the music itself doesn't sound horribly distorted, so you will be able to hear if your amplifier is distorting it. Make sure that the signal leaving your soundcard is full-strength; the only volume control that should be anywhere other than 100% should be in your amplifier.

If you hear distortion (which I highly doubt you will) you can connect a "gain" plugin in the kX DSP before the output of the soundcard, to turn the output signal down so it's not too much for your amplifier. If your amp can handle the higher level signal, it is much preferred that you leave the Audigy output level at full-strength, so as to get the best signal-to-noise ratio.

It is most likely that you will not hear any distortion at all, until the amplifier itself becomes voltage-limited and starts to clip. This would happen when it is very, very loud, most likely. It is a Good Idea to check for distortion when it's fairly quiet; if distortion is present at higher power levels, you can blow out the tweeters on your nice Hi-Fi speakers.

Best of luck! :-)

miguel

This overloading of input stage happened to me with an APS connected to a Panasonic Bi-Amp. As Nappylady says you should hear it distort no matter what level you set your amp to, so test at low volumes, then try moving up. I use a Gain-HQ right before output to -2 or -3dB and it's ok now.

CyberGene

Thank you for your complete answer! I will try that tonight. By the way - is it a good idea to generate a sine wave (or probably more complex wave) with the highest possible amplitude (in 16 bits) and use it instead of real audio records? SoundForge is capable of generating such waves for example.

Maddogg6

Additionally - KX DSP has a plugin called 'Wave Gen' or 'Wave Generator' (in KX Versions 3538H - 3538J at least - IIRC) that can create Sine/Saw/Triangle/noise - fully adjustable level and frequency (0-20,000 Hz).