Buy Guitar Amps
What's the difference between a tube amp
and a solid-state amp?
The simple answer is that a tube amp uses
one or more vacuum tubes to amplify the
signal, while a solid-state amp uses
solid-state electronics (diodes, transistors,
etc.) to amplify the signal. On paper and in
theory these two implementations should yield
identical result, but in actuality the difference
is usually noticeable.
But the simple answer fails to answer to the
complexity of the issue. Many amps are not
simply tube or solid-state, but mixes of both
kinds, called "hybrids." This usually means
that they have a tube preamp stage,
employing vacuum tubes in the tone shaping
circuitry, but use solid-state circuitry for the
power section. The hybrids are closer to full
tube amps in response and tonal warmth, but
purists will still find a difference between the
two. Tube amps are generally more expensive
in initial cost and to operate (because you
need to replace the tubes occasionally), and
solid-state amps are generally less delicate
and more reliable. Many players, however, feel
that tube amps yield a warmer, more musical
tone and better distortion.
Yet another wrinkle is tube emulation circuitry.
Many amps and preamps have sophisticated
circuits designed to act like tubes, and as in
all things, some are better than others. The
newest develop in amps are the modeling
amps, which not only emulate the tone and
response of tubes, but of specific tube amps.
These are in general pretty exciting amps, but
again, some are better than others at getting
specific models, and in maintaining the
sounds through a range of volume levels.
Another point to make about tube amps is that
bigger is not always better. You get the
distinctive tube sound most when the amp is
cranked up enough that the tubes are
saturated or nearly saturated. For this reason,
it is often better to choose a lower wattage
amp over a higher wattage amp, depending on
how and where you play. By the time you
crank up your 60 watt amp enough to saturate
the tubes to get just the right level of
distortion, you could be blowing your audience
out the back door. It might have been better to
choose a 20W amp that lets you get your
saturated tone without the ear-killing decibels.