Thermionic valves or electron vacuum tubes have been popular since Lee
de Forest introduced his famous "Audion" some 90 years ago,
giving birth to the "Electronic Age," without which the
"Information Age" would not have been possible.
By the late nineteen-forties, tubes were everywhere: in table
and console radios, TVs, computers, telecommunications, and industrial
machinery...... but progress and science marched on. The invention of the
cool-running and service-free "transfer-resistor," later called
by a team of physicists at Bell Telephone Labs in 1948 spelled the beginning of
the end for tubes.
It took the Hi-Fi industry (including H.H. Scott) awhile to really
new solid-state technology beginning around 1963 - 1964. Many music lovers were
convinced to trade "up" to the latest technology. Transistors were
cool running, maintenance-free, "better-spec'd," and seemed (at first)
to posses a more powerful sound. They were after all, by-products of Projects
Mercury & Gemini and who could argue with "space-age" technology?
Consequently, most tube equipment eventually was traded,
discarded, handed-down or relegated to the attic, garage, or dumpster.
Ironically, as the "Made-in-USA" manufacturers lost ground to the
onslaught of low-cost, Japanese-built, solid-state gear, the export of older
American-made tube gear found popularity among overseas audiophiles.
Fortunately a few
enlightened "filament-heads," (mostly electrically-amplified
musicians, and high-end audio purists) have kept the faith in tubes. For an
entertaining perspective, see:
Ric Manning's syndicated column: The
Gizmo Page: "Tube Gear from the 60's Still in Demand."
info, we highly recommend you read Eric Bourbor's "The
Cool Sound of Tubes," as published in the IEEE
Spectrum, August 1998 edition.
In short, tubes have personality and soul. Fact is, we love
the sound of tubes so much, we're willing to put up with and even romanticize
their often very real drawbacks.
To help learn the differences and commonalities for the more
commonly used tube types, the following pages feature basic "generic"
tube specifications from tube manuals. You should always consult a specific
vendor's data sheets for more precise data.