HVR-1950 Audio Distortion

[Paul D. Bellamy]

I have Hauppauge's HVR-1950, GBPVR v1.3.11, and WinXP, SP3. Over the past several months (perhaps since I installed the HVR-1950), I have noticed that several recordings have some annoying distortion when the actors speak loudly. It sounds as if some analog circuitry was being over driven and clipping the audio peaks. I never noticed this problem with my previous WinTV PVR-250. I have tried reducing the audio levels in as many places as possible but nothing seems to help. I've fiddled with the SoundMax Volume control but that doesn't do much. Is there a volume control in the WinTV7 v7.0.29160 software? I can't find it. What have I missed?

Can anyone suggest a way to clean up this distortion?

Thanks for any help.
Paul.