I’ve seen a few commercial and DIY tube-amp docks, but they’re expensive, uninspired or both. So I’ve come up with a version that anyone can build for about $400.

As JHS Pedals says, it “puts a half-million dollars of tone at your feet”, and that’s no exaggeration. There is no amp that’s more sought-after. The price of an original Dumble tube amp runs into a ...