On Mon, 20 Jul 2009 16:41:41 +0100, Jim Lesurf
wrote:

Your warnings about the distortion in the headphone output, but I'm
guessing that most people will use the line output, which I presume is
clean.

I don't know. But my experience makes me reluctant to presume line output
will be clean. So I'd say "maybe" to that.


Well, my card (which is on the decent side of medium) is an M-Audio
24/96, and seems perfectly happy flat out.

The *only* analogue out for the laptop I used is the headphone. So I'd have
expected that not to clip when fed 0dB. In fact it clips at a far lower
level than 0dB. This is when it wasn't even driving a load with an
impedance anything like as low as a typical headset.

When I listened with a pair of headphones the sound was very loud unless
you wound down the volume a lot. So the gain applied between the internal
DAC and the headphone output stage was needlessly high. Would have been
fine if this had been reduced so 0dB didn't clip. So it all seemed like
careless design to me. The usual idiotic motto: "louder is better".


None of that surprises me. Think of it like the volume control on any
amplifier. You don't expect the output to be just clipping from rated
input when the volume control is at max. If it did, most music would
be incapable of driving the amp to clipping. There is always some
slack, and your laptop's headphone socket shows that.

So for all I know some computer sound systems will also clip the 'line'
output. I can just warn people to be wary just in case. Check if you can.
Arny may know more about this. I've only been checking computer systems
recently once I'd developed and interest.

FWIW if I can blag a borrow I will try out some other USB 'soundcards' to
see how they work (if at all!) with Linux. Then report on what I find out.
A number of these have appeared recently. But I've only seen limited
results based on windows and macs.


Can you even get drivers for most of them? I use Asio here- I suppose
that is implemented in Linux as well?

d