Distortion--is it my soundcard or my H4 interface?

Hello everyone. I’m new here. I recently discovered Ardour and I’ve been having a lot of fun learning to use it to make music. I have been using a Zoom H4 as an audio interface (with its built in mics) to record myself on flute, sax, clarinet and bass clarinet. I have noticed a repetitive clicking type distortion in higher frequencies when I play loudly, especially with flute and clarinet, which sounds to me like clipping. This is present regardless of the level I set on the H4 (that is, even if i set the mic sensitivity at a minimum), and even if the input signal in ardour remains very low.

I am using Ubuntu 10.4 both with and without the realtime kernel, and the kernel selection seems to make no difference. The clicking is present regardless of whether I set Jack to use the H4 for only input or for both input and output.

I have also tried playing with settings for period and buffer size. This hasn’t resolved the problem.

Running the H4 and Ardour in 48kHz (instead of 44.1) seems to reduce the frequency of the clicks, but they are still present.

The H4 records with no clicking when I use it as a stand alone recorder and import the tracks later into the computer.

Is this a problem with the H4 in general, with my specific H4, or do you think it’s dependent on my computer or configuration?

I ask because I’m thinking about investing money in a more serious interface (leaning towards a Lexicon Omega), but if the clicking is likely a result of my onboard sound hardware (ATI Technologies Inc SBx00 Azalia (Intel HDA)) then I’d rather save my money for a better computer.

When recording without the H4 through the onboard mic (or plugging an external mic), the clicking is not present.

Thanks and sorry for the long post…

Since you’re only using the Azalia for playback it shouldn’t matter if the signal was recorded in Ardour through the H4 or just imported.

Have you tried recording the loud flute/clarinet with the H4 standalone? I’m thinking perhaps the mics are busted. An alternative would be to try using the external mic input and a trusted SM57 or something.

Do you have anything else USB related plugged into the PC when you’re recording?