🚀 go-pugleaf

Hello everybody. I am having problems with playing and recording digital 
audio using the combination of my sound board, a Turtle Beach Tropez, and 
my SCSI hard disk, an IBM DeskStar DPES31080.

I noticed that whenever I rec. or play audio at the 44100 Hz sampling 
rate with the above equipment, the samples get mixed with noise. When I 
play the audio, I can hear that the noise comes at regular intervals 
that match exactly the intervals of my SCSI disk's activity.

Some things I have tried are:

1) Lower the sampling rate: the problem goes away (but of course the 
frequency response gets butchered). Curiously, it seems that only the 
sampling rate of 44100 Hz has any problems; all other parameters such as 
sample precision and number of channels seem to be irrelevant.

2) Use my IDE hard disk, a Maxtor MXT7213A: all audio rec/play is 
perfect; no noise at all. However, when I copy the file from the IDE disk 
to the SCSI disk, and play it back at the latter device, the problem 
appears. (Unfortunately my IDE disk is too small for audio storage.) 

Also, if I copy an audio file recorded on the SCSI disk to the IDE disk, 
and play it with the IDE disk, the loudness of the noise seems halved. I 
suppose the act of recording to SCSI added a portion of the noise to the 
original file, and playing it from the SCSI disk gives twice the noise.

3) Try to shield my sound board, and move the hard disk away from the 
sound board: no effect, the problem persists.

4) Reduce drain from power supply (disconnected the IDE disk): no result.

Anything else I can try?

FYI, my SCSI interface is an Adaptec AHA-2842A (VL bus). Sound board is 
plugged into an ISA slot @8MHz, as far away as possible from video, IDE and 
SCSI interfaces.

Thanks in advance.

						Tow

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The FAQ file 1.10 for the TB Tropez sound board can be obtained by FTP from:
ftp.wi.leidenuniv.nl	/pub/audio/tropez/
ftp.hawaii.edu		/outgoing/Maui/   
ftp.netcom.com		/pub/jo/jonin/soundcards/faqs/
rtfm.mit.edu		/pub/usenet-by-hierarchy/comp/sys/ibm/pc/soundcard/misc
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