dc offset problem

Archived from groups: rec.audio.tech (More info?)

When i use the digital output of the A/D converter AD192 of the preamp
PRESONUS
EUREKA i get a DC offset that produce a low freq noise (about 0 to 10
hz)of -40 db . Is that normal ? Is the converter broken ? when i
connect the analog output
to my audio card there is no dc offset . To be sure that the problem is
only in the a/d converter of the presonus eureka i tried the digital
output with 2 audio card , the echo layla 24 and a soundblaster live ,
and i found the same problem .

Archived from groups: rec.audio.tech (More info?)

I get a floor noise of -40 db . if i use an hi-pass filter from about
10 hz there is no noise and there is no problem . I mine that the very
low freq close to 0 hz produce a noise of -40 db that you can't ear
,'cause human audible freq range limited from 20hz-to 20khz .
I found doing an analysis of the recorded wave that there is a dc
offset of 100% .
When i remove 'via' software the dc offset , the noise disapear .
You think the cause of this dc offset is the unbalanced digital output
of the a/d converter .
The strange thing is that when i use the analog output , i don't have
dc offset .The problem
is only int the A/D converter .