..I have a sansui 5000 x. I feel it's a pretty decent receiver..
There is a lot of AK (technical) info on this as
@kwayde so kindly listed for you.
I can share my experience, as I had a 5000x during ca.1978-1995 and used it intensively:
It served me well during my "wild" teenager years. It took all I threw at it, drove all kind of speakers, mostly LOUD (metal/rock/disco). It was the reliable base of my set up while other parts rotating (often as I blew up things). Often saw the red "protector" sign lit up and had to change a fuse sometimes. Only once blew a channel (while clipping speakers), but quickly back in business after a repair. The changing of some light bulbs was the only other maintenance it ever got. Never had a chance of getting oxidised contacts..
When I settled down it became our living room receiver, now pared with more sophisticated speakers and a cd player. Besides listening to more quality music, we also used the radio for long hours daily. And during parties the old 5000x still proudly showed its experience with loud and bass-heavy disco beats.
Finally it blew a channel (again) and I decided it was time to put the 5000x in to retirement. The facts that I did not have access to a good/reliable repair shop anymore and now had more money to spend contributed to this decision. And I probably just wanted something new and modern after all this time with the "old fashioned" 5000x (in my country receivers were not considered very cool). So I parked the crippled receiver at the attic of my parents (could not bring myself to throw it away) and I bought brand new Marantz "Spitzenklasse.." equipment.
Unfortunately this story has a sad ending: Years later my father gave away the 5000x away together with a (also crippled) Eight Deluxe as “it was just taking up space”..
Bottom line: The Marantz setup I used until ca. 2005 and then replaced them with vintage Sansui.
I recently gave away the Marantz units to a family member. I still regret not having the 5000x anymore as it was versatile, great sounding and reliable. And I loved the "black face" while not on tuner duty!
This is a long story, just to say I agree with you..
Have fun
-John-