From: META000 <META@UNB.CA>
Subject: Re: Tubes vs. Transistors
Organization: The University of New Brunswick
Date: Tue, 17 Nov 1992 22:02:31 GMT

In article <Bxt165.Ks5@dcs.glasgow.ac.uk> dam@dcs.glasgow.ac.uk (David Morning) writes:
>
>>In article <1992Nov12.010212.24138@eecs.nwu.edu> ray@eecs.nwu.edu (Jim Ray) writes:
>>>I need a new amp.  I have heard tubes are the only way to go.
>>>Transistors are much more reliable.  Is there a way to get the same
>>>effect of a tube amp at a small signal level or even digitally and
>>>then use a transistor power amp to get the volume?
>>>
META responds
>>This question of reliability is one ofthose myths that persist
>>despite evidence to the contrary.  I bought a 59 Fender Princeton in
>>1976.  It worked flawlessly at that time, andsince then, I have
>>changed the speaker, and little else.  Will someone explain to me
>>how this "unreliable" tube amp has gone so long with so little
>>maintenance?
>
>You've been lucky and treated it with care probably.
>
>>  In 1983, I boughta mid-60's Fender tremolux, also
>>vintage tubes, etc. andheld on to it for a few years, without the
>>need for any maintenance whatsoever.  At present, I have recently
>>acquired a 59 Bassman, and the only problems in it seem to stem from
>>dried out capacitors in thepower supply.
>
>...which is just about the most common cause of failure of a tube amp.
>
>I think much of this depends on how you define 'reliabililty'. If you define
>the tubes themselves as 'replaceable items', much as you would define tyres
>on a car as 'replaceable items' then on the 'tube wear and replacement' side
>it would be a bit unfair to term this unreliable just as it would be unfair
>to refer to a car as unreliable because you have to change the tyres.
>There are problems, however associated with the high voltages present in
>a tube amp such as tracking between pins on the tube sockets, capacitors as
>you have pointed out. Also the fragile nature of a tube makes it more prone
>to physical damage if you don't handle it with care. Heater filaments can
>go if it's thrown around too much or if it get's hit by a large voltage
>surge in much the same way as a light bulb filament.
>In addition, they require periodic adjustments to the bias to keep it working
>top notch.
>
>All this would be acceptable if you looked at cars and the way they are viewed.
>But if someone came along with a car design that never needed adjustment,
>handled all sorts of wild physical abuse and never wore out its tyres would
>you not start to redefine the terms of 'reliability' in relation to current
>cars?
>
>>If you LIKE the sound of solid state amps, that's one thing.  If you
>>like the light weight, and ease with which features like channel
>>switching are incorporated cheaply, that's another. But NEVER assume
>>that a solid state amp will somehowbe more trustworthy, last longer,
>>abreak down less, and be cheaper to repair, than a tube amp. Make
>>your choice based on the sound, features, and design.  Arguments
>>about reliability are moot when it comes to guitar amps.  Now, would I
>>buy a tube television?  A whole different kettle of fish.
>
>I'd go along with your comments regarding the SOUND of tube amps but I'm sure
>that it'd be pretty straight forward for someone to churn out MTBF figures
>for tube vs transistor amps which would show that the figure is a lot less
>for tube amps. What you've got to remember is that for every mid 60s Fender
>currently sitting in someones house, there are X lying on the scrap heap.
>Time has filtered out most of them leaving the 'creme de la creme' still
>working.
>
>Dave
>
>--
>.
>.
I think Dave raises some very pertinent points.  However, I think
it's also fair to consider that many people who purchase guitar amps
will simply plunk the thing in one location, and move it
occasionally to a friend's house to jam, or to the side to vacuum
behind it.  Personally, I don't treat my equipment with kid gloves,
but because I am a "noodler"and not a touring musician, reliability
under normal operating conditions is VERY easy to obtain.  I am not
throwing my amp up on a stage, or watching helplessly as it falls
offthe back of a pickup truck.I can easily see where under such
conditions, as Dave rightly points out, solid state designs can
offer higher reliability.  My point is basically that there are many
circumstances where reliability is a moot issue, and some
circumstances where it isn't.

Mark Hammer

Newsgroups: rec.music.makers.guitar