The matrix series cross-overs like more juice to make the speakers come alive. The tube amps will drive the speakers but a high current (note the word current) SS amps drive the speakers much better. It also depends on how loud you like the music also. I used a friends Graaf 5050 on my M803 SIIs and it sounded OK but the Pass X-250 SS amp blew it away. On other speakers, there were differences but not as large.
Happy Listening.
Happy Listening.