Tubes rule. Slone drools

A good deal of this book is an attack on esoteric audio in general and
vacuum tube equipment in particular. But just because Mr. Slone hates
tubes (and he does, although he can't be honest with himself, like most
fundies, and so has to attempt to disguise his real motives) doesn't
change reality. Measurements aside, all other things being equal, tube
equipment generally sounds better.

If you listen to good music at normal volume, in a normal house, the
average power output of your amplifier is almost always between 10 and
500 milliwatts. You can prove this with a DMM that has at least a 20
kHz AC bandwidth and peak and averaging functions hooked across your
speaker. The Class B Lin topology solid state amplifier with large
amounts of global NFB, which Slone describes and advocates to the
exclusion of all others, does very well at between 5 and 100 percent of
its rated power, but is terrible at between .01 and 1 to 2 percent of
rated power.

There are various circuits to work around the problem, but Slone
ignores them. When you refuse to accept the problem, you can't be part
of the solution.

There are several possible solutions. One is the venerable transformer
coupled vacuum tube amplifier, which for all its technical flaws, does
reproduce music beautifully. There are modern tube amps that are
universally acknowledged to sound great, have long tube life (in the
tens of thousands of hours) and have distortion measurements in the
same class as most solid state amplifiers. There are also solid state
amplifiers that use innovative circuits and careful device
matching-semiconductors are inherently much more variable in device
parameters than tubes, which Slone conveniently forgets to tell you-to
"give good first watt" while still providing peak power reserves
traditionally associated with solid state designs.

I have heard an amplifier built to Slone's schematic on Slone's PCBs-in
fact I set it up on my company's distortion analyzer after hours-and it
meets his published specs fully. Hooked to my Klipsch LaScalas it has
all the sonic elegance of a Peavey CS-400 I happened to have on hand-it
makes Blossom Dearie sound suspiciously like Louis Armstrong on her
quietest passages, and Angel Romero sounds like Dick Dale is doubling
up on his thumb lines in the distance.