When recording from DAT to my PC using my soundcard's coaxial SPDIF
in, I find myself getting occasional pops in the recorded WAV. I
suspect that this is due to me turning on and off my amplifier. I
have my TV, Tivo, amplifier and DAT on one surge protector and my
computer on another surge protector and both surge protectors go into
the same wall outlet.

Does anyone have any advice for me to eliminate these pops? I could
just stop turning off my amplifier while recording, but I don't know
if other electrical equipment will affect the recording also. I did
experiments turning on and off my amplifier at 10 second intervals
while recording and did indeed get some pops at those points. Tests
turning on and off my TV and Tivo proved inconclusive.

If I were to buy a UPS for my PC, will this help me? Should I also
have a UPS for my amplifier/TV? Is the cause of the pops due to a
power "spike" affecting my PC/hard drive's power source, or my DAT
machine's?

I am using an M-Audio 1010-LT soundcard.

Thanks for any help!

When recording from DAT to my PC using my soundcard's coaxial SPDIF
in, I find myself getting occasional pops in the recorded WAV

I suspect it's do to clocking issues. Make sure your soundcard is slaved to
the incoming clock from the DAT machine.


Joe Egan
EMP
Colchester, VT
www.eganmedia.com

Hi,

Thanks for the responses!

It could also be due to noise pickup by the coax itself. How long is it, and
how is it routed?

It's 6 feet and goes from my Tascam coaxial out to my soundcard SPDIF
in. Should I be routing it in a particular way?

I also tried using a short 7 pin to coaxial SPDIF cable (less than 1
ft) going from my Sony D100 to my soundcard SPDIF in, with the same
problem. This led me to believe that it wasn't the coaxial cable's
fault, but of course both cables could be to blame. But I used to
have a 3rd cable that I used with a different computer and seem to
remember having similar problems, and the short cable worked for me
then.

Yes, my soundcard's master clock is locked to the SPDIF in.

karatebabies wrote:

It could also be due to noise pickup by the coax itself. How long is it, and
how is it routed?

It's 6 feet and goes from my Tascam coaxial out to my soundcard SPDIF
in. Should I be routing it in a particular way?

I also tried using a short 7 pin to coaxial SPDIF cable (less than 1
ft) going from my Sony D100 to my soundcard SPDIF in, with the same
problem. This led me to believe that it wasn't the coaxial cable's
fault, but of course both cables could be to blame. But I used to
have a 3rd cable that I used with a different computer and seem to
remember having similar problems, and the short cable worked for me
then.

Yes, my soundcard's master clock is locked to the SPDIF in.

It's not the cable.

It might be a ground loop, though. A lot of "S-PDIF" interfaces today
don't actually follow the spec and aren't transformer-isolated. But if
it's taking place with your D100 running off batteries so there is no
other ground connection between the two devices, it's not a ground loop.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

Scott,

It might be a ground loop, though. A lot of "S-PDIF" interfaces today
don't actually follow the spec and aren't transformer-isolated. But if
it's taking place with your D100 running off batteries so there is no
other ground connection between the two devices, it's not a ground loop.

My D100 was not running off batteries, I had the DC in plugged in. So
if it's the ground loop, do you have any suggestions? Should I plug
my Tascam to a different wall outlet, etc.?

Also, I was wondering why are you able to dismiss the cable as a
possible culprit?

Thanks a lot for your help!!