We are trying to setup an asterisk system using the tdm04b card in a Debian environment.
All sounds internally sound great. Outgoing/incoming call sound quality is fine but if the caller gets the auto attendant from an outside line it sounds like Darth Vader. The music on hold also sounds like static garble.
The auto attendant internally sounds great as does the music on hold. The issue only arises when the call is routed through the card into the POTS lines. We have tried POTS lines outside of the building we set it up in with the same result.
We have tried 4 different boxes with the same effect every time. The one thing we have not changed is the hard drive which we think may only be a 4200 rpm.
We have also tested the card in a working system and everything sounded fine so we know the card itself is not defective.