List Of Small Company Tube Amps

This list is a very worthwhile endeavor. Here are two I'll add:

Supratek (Mick Maloney from Australia. See the "Preamp Deal of the Century" thread in "most popular of all time" tab on this forum)

Alan Eaton

Also, if it hasn't already been mentioned, the website "glowinthedarkaudio" has wonderful photos and descriptions of many of the boutique builders amplifiers.

Whammerdyne for sure! I certainly LOVE my 2A3 stereo amp.

Trafomatic?  Margules?  Triode Corp (Japan, not Triode Labs, Canada)?

Raven Audio meets and exceeds the OP’s criteria and they are really nice people to do business with.

on the other hand…

Roger High Fidelity is overpriced even at his 50% off eBay prices, and the lifetime “transferable” warranty is a joke. Transferring the warranty requires sending the amp back for recertification which incurs a bench charge, which is fine, until he sells one of his amps to your buyer instead, which he did to me, twice.

Ironically one of those buyers hated the amp and put it up for sale within a few weeks.

The $8500 I spent on the “demo” EHF MK2 was by far, the worst expenditure in my audio journey.

Check out Musical Paradise, esp. if don't want to sell a kidney for an upgrade.