Recently I have read Morgan Jones' Valve Amplifiers.

Does there exist any relevance for Valve Amplifiers in these days of semiconductors ?

 

All amplifiers introduce some coloration of the signal (distortion). Some like the particular type introduced by valve amps.

 

They smell nice.
They keep you warm in winter.
They're less likely to blow up during a power surge.
They make a lovely "pink" noise when you tap the glass with a screwdriver.
They're more resistant to the electromagnetic pulse from a detonating nuclear weapon.
But mostly, as studiot says, some people like the sound.

Morgan Jones lives just up the road from me. I must buy him some pints one day.

 

Valves promote (generally) 2nd harmonic distortion (and other 'even multiples'), which are pleasing to the ear. Some wiseacre will talk about how some output stages have odd-order components, which is true, but proper design minimizes the effects, and I am basically referring to preamp triodes here.

Semiconductors distort basically by abruptly 'sharp clipping', generating odd-order (3,5,7 etc) harmonics, which sound shrill and fuzzy. Even MOSFETS and FETS clip abruptly, although the are "closer" to tube sound than BJT's. But not quite there, ha ha.

So discerning musicians like the gentle entry into clipping that tubes offer...semiconductors have their place in hard music (modern metal, thrash...) but for most other applications, tubes will be warmer, b@llsier, and just seem more touch responsive to the player.

~Mike (guitarist and amp builder)