[vt102]

I know a little about tube guitar amps, and my understanding is that they are desired due to their “defects” compared to more accurate solid state transistors. I would assume headphone amps would want pristine amplification— why would you want tubes, then?

[voldacar]

The slight touch of harmonic distortion from a tube amp can sound nice, even though it might not be totally transparent. Tube amps are also a lot of fun to build and tinker with because of the huge diversity in tube models, the operating point at which the tubes are run, the gain stage topology, power supply designs, etc. Personally I find that different tube designs almost always sound a little different from each other while well-designed transistor amps sound indistinguishable or almost indistinguishable from one another.

Pete Millett, who runs a DIY Tube site, made a good presentation on this: http://www.pmillett.com/etf_sod.htm

[jacquesm]

> Tube amps are also a lot of fun to build and tinker with because of the huge diversity in tube models, the operating point at which the tubes are run, the gain stage topology, power supply designs, etc.

You could say all of that about FETs and regular transistors too.

[voldacar]

Yeah that is true, but with tube amps you can tinker around with the circuit and actually hear a meaningful difference, which is more difficult with solid state amplification IME

[holy_city]

Those "defects" is just non linearity in the circuit. At low gain factors (much lower than a guitar amp) it creates prominent 2nd, 3rd, and 4th harmonic distortion (depending on the circuit) which corresponds to the musical intervals of an octave, octave + fifth, and 2nd octave. That sound is typically described as "warmth" and can be quite pleasing. It also increases the RMS of the signal without (greatly) affecting dynamics, which makes it perceptually louder.

Some people like the ultra hifi systems with crazy THD+N metrics, with super flat speakers in the deadest room they can find to get the most "pristine" sound they can. Other people like listening through systems that subtly color their favorite recordings to match their taste. Different strokes for different folks.

[detaro]

Tube amps (as do transistor amps) can vary quite a bit in how much they change the sound, e.g. part of the appeal of tube guitar amps is that you can drive them out of the area they work "most precise" into distortion, and that distortion sounds interesting. And some people like the sound changes tube amps cause for listening.

[C1sc0cat]

There is an story that when the Beetle's went to record at the BBC there was an argument with the BBC sound recording Engineer that no way was he allowing distortion to go out on the BBC :-)

[billfruit]

I am no EE, but transistors also have problems giving precise accurate gains as well.

[jacquesm]

That depends on how much energy you want to waste.

https://www.electronics-tutorials.ws/amplifier/amplifier-cla...