Tb69396: Sorry to learn of your problem. By chance did you buy from Musicans Friend ? They sent mine Fed Ex no problem. Several years ago I was trucked a CJ 100 that was pretty banged up when I opened the box . I had to drive to N. Va from Towson, MD 3 x to fix the Amp.
Tb , are you awaire that when the 500A is used solo it rating is 130w @ 4ohms. I'm uncertian of the load factor for the focus but possibly the ohm rating was off resulting in thin mids , weak highs and bloated bass. Sometimes a resistor change within the amp or added to one link of the interrconnects can restore balance . Sounds bad but fixable.
The Denon is a good unit . A nice alcohol swabbing of the of the connections , a little fine sand paper on the plug , alcohol soaked cotton balls to clean the prongs of any residue w/ a touch of 3-in-one-oil on the cleaned plug prongs , hook it up and away you go to music-land. You could also crack the case replace the fuse with one of those upscale 24k units ( at approx. $30 ea.) & sapp the connections on the back w/ a little battery dc from a Aq Phono Demager to recalabrate , putting a Eagle socket in the wall($1.49). The re-do will flip you out. Best of luck!