Gmoon wrote a hefty(22-step!) how-to for constructing your own sweet-sounding tube based guitar amp. Even if you’re not planning on specifically building this project, there’s a lot of really helpful details told from the maker’s perspective (even some informative regrets) -

No project is without lessons learned. In this case, I wish I had:
–Used a heaver, possibly stock, metal chassis.
–Substituted a 10 inch speaker.
–Used a turret board, instead of point-to-point. The more I modified the project, the more a tangled web it became. After this project, layout for turret board makes perfect sense–tubes on the back, controls on the front and the component board between….

- Guitar Tube Amp on Instructables