tubes are warmer


2016-03-01 4:10 pm seems to amount to bigger sound in the bass range.
Well, that's certainly not what it means to me. Boosted / sloppy bass can be obtained easily from any kind of amp, if that is what one wants - valves don't have a moratorium on producing bad bass!

Note also that many musicians pay lots of money for guitar amps with relatively small, open-back speaker enclosures: this sort of speaker enclosure guarantees very little deep bass!

What I hear, and like, from valves (for guitar amp purposes) is the presence of large amounts of low order harmonic distortion. A single 12AX7 triode stage can produce well over 5% distortion, mostly 2nd and 3rd harmonic, while still sounding "clean" to a guitarist. (Note that this is literally thousands of times more distortion than you get from a reasonably well designed modern solid-state Hi-Fi amp.)

This added distortion is significant only because of the weaknesses of the instrument itself: electric guitars, particularly solid-body ones, produce a rather boring and sterile timbre on their own. This is because the guitar itself doesn't produce lots of strong harmonics of the note that is being played. Compare the boring "pingggg!" produced by a solid-body electric guitar plugged into a solid-state, Hi-Fi amp to, say, the rich timbre of a cello, and you'll know exactly what I mean.

So the distortion from the valve guitar amp, to some degree, makes up for the lack of rich timbre from the instrument itself. It becomes part of the sound of the amplified electric guitar.

For accurate reproduction of music, this is not at all what is wanted, and that's what the entire field of Hi-Fi was about when it was still an engineering field, before the subjectivists got involved.