this is where its peculiar...
a hifi can cost over 100k... before even buying speakers(add another 75k...each!), but oh my...
you have to actually listen to a high quality one to realize why someone pays that much.
a tube can distort, its the whole reason music got to the point it did in the 80's or so, until the synth and the digital revolution made an appearance and destroyed everything. but its the way it does distort thats the key!
in hi-fi, with a bit of number crunching...one can get a lot of amplification, a lot of dynamic range, and of course... NO distortion!
in fact, armed with just a multimeter and a data sheet, you can make a pretty good tube amp, with say, 1-2%distortion (not great but definitely listenable), with absolutely NO MATHS!
hifi is NOT guitar amp tech though... where you WANT distortion...
dynamic range is important. transistors will always require several more stages to achieve the SAME gain, with equal distortion...and so lose all the dynamics. each stage compresses the signal. each stage reduces the extremes between soft and loud... each stage attenuates certain frequencies... add it all up and the more stages...the worse the reproduction gets. every component adds noise.
a 10watt class A tube amp will put even 100 watt solid state to shame for sheer volume... and wont burn out your speakers due to driving straight DC through the voice coil when it starts clipping signals.
a transistor/solid state is perfect for switching on and off, ie...puters. this is where they really reign supreme. small, low voltage/power, cool running, cheap, and easily made in miniature. they dont require a heater, high voltages or any of the dangers associated with HT supplies. smallest tube i have is still as fat as a pencil and about 1 inch long...
but they arent so good as LINEAR amplifiers. hard to explain that one to anyone that hasnt delved into theory of tubes much. i had this argument with an electronics engineer, him saying that tubes are obsolete and distort everything... and now he makes top-end tube amplifiers for studios... go figure!
they distort LESS than solid state. a transistor has a terribly non-linear amplification curve, takes a lot of maths to get it approximating a straight line at all. and then the range it can cover is limited... ie, from 0.6 volts to 0.9 volts...anything below, its OFF, anything above...its ON... all this nonsense about thermal runaways and negative coefficients etc... temperature compensation, yarda this yarda that...
while a tube can swing from nothing to say, 300volts... and do it fairly well in sync with the input... only a little adjustment here and there and its near perfect.
the guitar amplifier is just a special case where, in the pursuit of more volume, this side effect, overdrive, started to become apparent...
not from intentional design, but by accident! all that great music...floyd, berry, clapton, whatever...all due to an accident!
of course, now its been studied and perfected to the almost nth degree... you can go either way...crystal clear perfect audio reproduction, where you can seriously hear the splices from the tape editing, the guy out the back that coughed halfway through a take, to absolutely filthy shredding sounds...
solid state distortion, due to the harmonics created, always sounds distinct to tube distortion.
and theres about five different types of distortion...some pleasant, some not so pleasant. its finding the blend that works best that takes practice.
this is before contemplating how the speaker itself affects things. thats a whole other kettle of fish!
they also have the advantage of not requiring any input current. you can have a voltage without any current...thats electrostatics. they can reference the changes in voltage across a resistive divider...without becoming a resistive element that affects the potentials across the divider itself. imagine a multimeter that can take measurements but has no actual circuit inside to affect what its measuring...
but you cant have a current with no voltage! (E=IR)and all silicon junctions require 0.6v to start conducting... 0.2v for special items like schottky diodes. unfortunately, they require a minimum current to reach that voltage.
to make an analogy... transistor, to get the valve to open, you have to pour some water down the inlet. so you need to replenish the water supply. (current=flow) this places a load on the signal source. this creates its own type of distortion, and effects the way the signal source operates.
tube, to get the valve to open, you simply have to lift the cup up, no need to spill any...(voltage or potential=height) this places no load on the signal. no load, no distortion or unexpected effects.
my head hurts. :wacko: