From: ohumukin@spectra.com (Kawika Ohumukini)
Newsgroups: rec.music.makers.guitar
Subject: Re: Tubes vs. Transistors
Date: 16 Nov 92 16:53:06 GMT
Article-I.D.: spectra.1992Nov16.165306.19166
Organization: Spectragraphics Corporation

In article <15NOV92.16864592.0199@UNBVM1.CSD.UNB.CA> META000 <META@UNB.CA> 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?
>>
>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?  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.
>
>Tube amplifiers may take longer to warm up, but unless one acts very
>rudely towards them, I find their reliability to be every bit as
>high as top of the linesolid state stuff.  Any problems that occur
>have less to do with the tubes than with the accompanying components
>(caps, transformers, etc.).  A second advantage of tube design is
>that tubes may beremoved and replaced with other models/brands, to
>yield somewhat different tones.  Altering the fundamental timbral
>characteristics of a solidstate ampisa major undertaking by
>comparison.

Hi,

This is a reply based simply from a technical and physics standpoint.
Tubes
-----
Tubes consists of plates and screens.  The electrons fly from one
plate--through a screen(s)--to the receiving plate.  This bombardament
of energy is what causes tubes to degrade.  Eventually the transmitting
plate loses more and more electrons until it is not transmitting
as many electrons which affects harmonic content.

Transistors
-----------
Transistors consist of substrate material.  The electrons flow through
the material which need not "transmit" the electrons.  The electrons 
merely pass through the material.  The transistor therefore does not
degrade as a result of electron bombardament.  A transistor will degrade
from heat on the substrate.

As far as reliability, transistors cannot go into a state that tubes
go into called "gaseous" which is when the tube appears purple.  
Tubes require a much higher bias current than transistors.
Tubes will fail far sooner than transistors.  
Transistors are far cooler than tubes.
Transistors are far cheaper and more easily transported.
Transistors can be changed when sockets are used, usually the case.


So why use tubes?
Simple.  Tubes amplify odd harmonics far superior to transistors.
This makes a cleaner sound even when distorted (artifically introducing
even harmonics).  This makes a "truer tone".  The other fact is that
since tubes use such a large area to transmit/receive electrons, more
electrons can be passed providing higher power ratings.

Transistors are becoming more advanced and more linear to odd harmonics
and the supporting circuitry is getting more advanced to where they can
nearly amplify similar to tubes, we are not there yet.  Transistors are
also always being manufactured in new ways so as to come up to tube
power.  We already have extremely high powered transistors.

[stuff deleted]

Kawika