A lot of opinion but some good information

This short book covers construction of tube audio equipment for
beginners. I like to build tube audio-it's definitely more homebrew
friendly than solid state and often sounds better-but I think one
should have a better electronics background before starting these
projects than Rozenblit presupposes. I think absolute beginners should
start with the bookwork first and then build simple projects such as
regenerative receivers with FET's before moving to tubes and then line
powered audio gear.

This is a reasonably good but not really comprehensive book, best
picked up after you can solder, use test equipment-you cannot build or
troubleshoot without a generator and some kind of oscilloscope as well
as an AC voltmeter accurate to .1 dB from 20 Hz to at least 30 or 40
kHz, and people who tell you otherwise are misguided or lying-and
follow schematics pretty well.