Here you may find comparison between Sony STR-6055 and Sansui Eight Deluxe. I'm a great fan of Sony STR-6065. I found it superior to Marantz 2270 or Yamaha CA-1000 which I both also had.
https://www.head-fi.org/threads/calling-all-vintage-integrated-receiver-owners.537704/page-862
Round II, Match II:
Sony STR-6055 vs Sansui Eight Deluxe:
Also very close, as in they sounded much alike. In the end, the Sony seemed just a bit richer and more detailed, but just very slightly. Just a bit more air, with percussion (hi hats, brushes) just a bit more splashy/present.
Winner: Sony STR-6055
The Final:
Sony STR-6055 vs Fisher KX-100:
Well, unfortunately, this was somewhat inconclusive. There was some volume fluctuation, despite my efforts to use signal tones, SPL meter, etc. First one channel of one was just a bit louder, than the other, and it seemed to change a bit over time, which made things harder. When I'd think one was coming out ahead, I found it was just a tad louder than the other. I brought my 8-yr old daughter (and her better hearing) into the mix, and she preferred the Fisher, but it's really hard for me to say at that point that the Fisher wasn't a bit louder.
This was done over two days, but still, by the end of this, I was pretty fatigued from all the careful listening, swapping of gear, wires, etc. So rather than fight with the volume issues further, I left it as co-winners. The Sony was the best SS by a hair, and the Fisher was the best tube by a bit more than that. Some time it would be fun to face them off again, with more people involved to give their opinions.
I think it's impressive that the unrestored Sony could be in the same ballpark as a fully restored, tube classic like the Fisher. But it did, so cheers for both winners.