Bayne,
I had an older Sanyo receiver that did a similar thing...It appeared to be dirt in the volume control...The process below is provided that the unit you have is using a potentiometer (POT) to vary the volume.
What I did to eliminate the issue was to open the case and spray the volume knob control pot on the inside of the case with Electronic Contact Cleaner [found at electronic component retailers] (without power connected and without it on) and then rotated the knob from one extreme to the other a couple of times...
I also cleaned the "balance" knob (yeah...it was that old) in the same manner.
[Disclaimer: Try to use a tube to direct the spray only into the pot for the volume...Try not to overspray any other components...if you do, let the solution totally dry before attempting to power it up again...it usually is a very fast drying solvent, but it is better to be overly safe than sorry...]
After letting it dry for at least an hour and then power it up and try it again...
Made a difference with my unit...you may not be able to perform this process on yours.
Another idea: Unplug the unit and rotate the volume control from one extreme to the other a number of times (no contact cleaner this time]...it may be just dust buildup...
Just my .02.
Good Luck,
WhatFurrer
