Looking into options for a center channel amp for my Oppo SACD. My Sansui QRX-9001 quad handles the front and rear channels nicely via four channel direct, and I've been using one side of a Carver Cube to drive the center using an attenuator on the patch cord to tone down the volume. The Carver has developed "issues" and needs to be replaced, and it's always been certainly overkill for the application. The front channels are actually routed from the Sui's pre outs to the ST120.
I like the idea of a mono tube amp ... maybe a kit? Don't need a lot of power, and it doesn't really need volume either, as I can adjust the output from the Oppo ...