I'm thinking about building a tube amp kit for a cd player /bluetooth / chromecast to pair with some Klipsch bookshelf speakers. Hoping to find something around 15-20 watts per channel and under $700. The Dynakit ST-35 looks interesting but I don't see a volume control or switched inputs. I would rather not add a preamp as that adds cost and complexity. Maybe Elekit or others? It would be nice to find something available now versus 6-8 weeks from now. Any suggestions would be appreciated.