On 5/27/04 6:40 PM, in article y7utc.5462$eY2.1777@attbi_s02,
" wrote:

Bruce J. Richman wrote:

Tube amplifiers have both their proponents and detractors. Comments about
lack
of reliability and/or high repair needs from the latter group are, AFAIK, not
supported by any empirical evidence indicating those claims are valid.

Lack of reliability or the converse is relative. Given equal design
attention to reliability, tube amplifiers are simply not as reliable as
solid state amplifiers, especially as regards power amplifiers. The natural
manufacturing variances in tubes themselves, the the increased heat produced
by
them, (meaning increased stresses on associated components) and the higher
voltages dictate the empirical facts of the matter.

A tube will generally have fewer hours on them between replacement than
semiconductors - though the repair is fairly straightforward and simple for
an end user to do. A semiconductor failure is generally catastrophic in
that it will blow up and the amplifier will have to be sent in for repair.