[AG-TECH] hiss from gentner AP800

Robert Olson olson at mcs.anl.gov
Mon Nov 26 13:56:59 CST 2001

What sort of speakers do you have? If you have powered speakers, and there 
is an error in the routing, if you have the gain turned up very high you 
are likely to be generating some hiss.

I'd recommend going through the audio balancing steps at the end of the 
audio tutorial at


If you successfully go through all of these steps, your system should be 
happy. If one of them fails, you will have pretty closely pinpointed the 
problem you may be having.


At 12:48 PM 11/26/2001 -0700, Stewart, Corbin J wrote:
>We are also experiencing a hiss.  We're using the AP400 with Analog
>Like you we've traced all the connections and we are
>about to swap out the soundcard.  We have the added problem that we cannot
>audio.  The genter's meters indicate that signal is being sent to the audio
>but the RAT doesn't seem to see it.
>Sorry I don't have an immediate solution but I'll let you know if we get rid
>of the
>Corbin Stewart                               cjstewa at sandia.gov
>Videoconferencing & Collaborative Environments
>Sandia National Laboratories California
>-----Original Message-----
>From: James Miller [mailto:millerjw at mailer.psc.edu]
>Sent: Monday, November 26, 2001 11:30 AM
>To: Access Grid Techs mailing list (E-mail)
>Subject: [AG-TECH] hiss from gentner AP800
>I am trying to resolve a major hiss problem with our AG node.  I am getting
>a lot of hiss out of my monitor speakers.  I think I have narrowed it down
>to a problem with the AP800.  If I disconnect all of my inputs to the
>gentner, the hiss is still there.  When I disconnect the speakers, the hiss
>stops.  This tells me the hiss is not coming from cable interference to the
>speakers and it is not coming from the MatchMaker/Audio node.  If I mute all
>of my inputs, the hiss remains.  If I mute the speaker output from the
>gentner, the hiss lessens, but does not disappear.
>Has anyone had similar experiences?
>Jim Miller
>Network Engineer
>Pittsburgh Supercomputing Center
>4400 Fifth Avenue
>Pittsburgh, PA 15213
>mailto:millerjw at psc.edu

More information about the ag-tech mailing list