I have one of the first Yaesu FT-920's produced.  A great radio - love all the features.  Spend most of my time on CW but when I have the occasion to work SSB, I find the received audio to be a bit unnatural sounding. It takes much fine tuning to get decent sounding audio.  I have expanded the IF offset via the menu and this helps a bit but the receive audio still does not compare favorably with ICOM or Kenwood radios side-by-side.  Tx audio reports are great.  Any ideas on this before I call Yaesu service?  Also, is a service manual available for the FT-920?