> Why would you use tubes if you're not making guitar distortion?

I'm planning on building a stereo Mullard 5-10 next year, I know it will be objectively worse than a modern HiFi amp or even a more recent valve-based design at actually being an audio amplifier but I think it would be a fun anachronism to use a homebuilt 1950s amp with modern equipment and there's a lot to be said for the aesthetics of valve amps as well.