[TenTec] Audio distortion in Omni VI(standard)

[k8vf_mark at centurytel.net]

I recently picked up a beautiful Omni VI which works perfectly and is full 
of filters.

It has a slight audio distortion on SSB receive.
I tried 3 speakers all the same.

Tried transmit, beautiful, so it shouldn't be the power supply.

Has anyone run into this?  Of course I am hoping it is an adjustment, but 
would like to clear it up if someone has experienced this issue.

NB is fully Counter Clockwise.

I have had several of these but have not heard this before.

Thanks for any help.

Mark
K8VF