I know they're probably not recommended on this measurements-oriented site, but a lot of people like OTL tube amps with higher impedance phones like the HD6xx. Is there possibly some measured shortcoming of those amps that actually improves the sound subjectively? I realize this falls under the "some people like distortion" explanation possibly, but, as someone new to the tech aspects, I wondered if there is a specific measured shortcoming that could be pointed to as an explanation for some people's preference for those amps. And though I assume this is less likely with solid state amps like the Jazz, could a solid state amp, in theory, have the same measured flaw that may cause some people to prefer OTL tube amps?
Preference for something can be based on a LOT of factors (more often than not based on knowing/seeing).
OTL tube amps usually can supply a LOT of voltage in high impedance headphones giving it 'authority' in the lows. They can play a lot louder than most SS designs without clipping.
Also these tube amps also show mainly 2nd harmonic distortion and in much lower level 3rd harmonic when playing loud.
As most instruments have lots of harmonics these added harmonics aren't that sound degrading as one might expect.
However, aside from harmonic distortion there is also IM distortion which is not 'musical'.
At lower volume there is very little distortion added though.
Disadvantages could be noise levels, microphony and longevity of tubes.
Aging can go quickly, abrupt or take quite a long time.
Then there is the warm 'glow' of tubes together with it's reputation.
Don't forget the 'quality feel' you get handling/lifting these which adds to the idea you are handling 'something good'
And yes, one can get very low distortion with tube amps and also can build SS amplifiers with similar bandwidths and distortion 'character' as some tube amps.
What one rarely sees is that tube amps owners compare their amps in truly blind and level matched conditions.
If they did I am quite sure most goldeneared listeners may not be able to distinguish between quite a few amps.
As always aside from several gems, good performers there are also crappy designs both in the SS and tube amp camp.
This can be irrespectable of its price.
The strong point of the
Jazz is crossfeed (some like this, others don't) usage with lower impedance headphones and sensitive IEM's.
Disadvantage is it won't attenuate all the way down to quiet which may be an issue with sensitive IEM's and it cannot supply a large voltage swing so high impedance headphones will not play loud and with 'authority'.