Both tube and Solid State. I have a Grado Ph1 SS phono stage that I recently blew up. It's fixed now and currently I am swapping op-amps and bypass capacitors into it to improve it's sound. My current preamp is a (tube) Sound Valves VTP-101, which very recently replaced a (ss) Forte 44. Before the Forte was the (SS) Hegeman Hapi2. Before the Hegeman was NAD, SAE. The Acurus L10 I mentioned was for my son, who prefers an Apt Holman Preamp. The Acurus sits in a cabinet with the Forte as spares.
My amplifier is an Aragon 2004. Can't say enough good things about that one. Before that was an Apt A-1, before that was a Phase Linear 200. I built a Hafler DH110 SS power amp for a friend years ago from a kit (my standard fee is a bottle of single malt) and found the amp very musical, though not as sweet as the Apt. He borrowed my APT, bought one himself and never went back.
I have 3 Tube amps not in use because they all need service, a Dynaco ST70, a Fisher SA-300B, and a Golden Tube Audio SE40. I haven't decided what to do with them yet. The Aragon is really sweet and detailed, and has the power necessary for my speakers, The Large Advents. I'm not sure any of the above mentioned tube amps have enough power to really drive the Advents.
Yeah, the capacitors start to go, but fortunately, there's a lot of options out there that can really improve things. BTW, tell your dad not to forget the capacitors in your speaker's crossovers, they too can go, and possibly ruin your speakers. I replaced mine years ago with some audio grade models, and the speakers got clearer.
Who would've thought??