Sound recording from analog source

["Piekenbrock Thomas (NMP/Tokyo)" <thomas.piekenbrock@example.com>]

I recently tried to record sound from a microphone
using  arecord, creating .wav files.

The microphone is connected via analog amplifier to
the analog sound input connector of the PC (IBM 570
laptop). The same happens when I use radio or tape
as analog source.

In gamix I only activated the channels needed (input
gain, input mux, line). The recording result was quite
nice, except after the first about 50 sec, I got a kind 
of scratching noise every five seconds. This was exactly
each time when the hard disk control lamp had turned on
during the recording.

Has anyone encountered this phenomenon before or has an
idea how to avoid it? I tried by running as root with 
negative <nice> factor, under KDE2.2 and fvwm2, with 
50 MB still unused memory, but no success. 

Should I use a different recording software, or different
PC hardware? Who has done recording from analog sources
unter KDE before?

Any advice is appreciated.

Thomas

-----------------------------
 personal note

I enjoyed Oct-19 Nomikai, which was my first one.
I am from Germany, working for Nokia in Japan.
I am privately running SuSE Linux 7.2 with KDE2.2 from a 
second hard disk on an IBM Thinkpad 570, but planning to 
buy a desktop w/o M$ stuff for the family.
What works already:
 - Japanese and Chinese input
 - Staroffice 6.0beta with Japanese and Chinese
 - Brother HL 1240 laser printer
 - Acer 4406 USB CD-RW
 - NTT 128Vmini ISDN terminal adapter