Have not had extensive expierience with the big 5802 but,
the 5500 is a wonderfully musical amplifier.It all just took
long break-in and trying out cables and interconnects.
I believe Nelson Pass of Pass Labs was contracted on the design of this and the 5802.At 200wpc,and it is biased to run class "A" for first few watts and sounds very liguid
up to that point of running "AB".With efficient speakers
and smaller rooms the 5500 has very nice sound indeed.
Since it runs class "A" first few feet out off the gate I have found it to work its best as the top end of a bi-amp set-up to make the most of this best portion of the 5500's sound,the bottom end was run by modified 555II.This all adds
up to relly nice imaging,sound has depth and dimension and
images extend out into and beyond loudspeaker posistions.
Small details in the mix have thier own space.This amp does micro-dynamics well,bass is its weakest point in the bang for buck sense,in which case the 555II may beat it by a nose
The design balances several strengths of Solid
State and Tubes and has a definite "nitch" at $1,200 retail.
Can be found used much less used.