The answer to your 3 questions is 'yes'.
Different tubes can change the tonal balance, the level of detail retrieved, and the level of distortion added--and probably more.
Differences in tonal balance can make the system sound forward or recessed, brighter or darker (more or less treble energy), warmer or cooler, etc. Tubes can sound more or less detailed and more or less spacious.
Personally, I find these charactersitics to be subtle but real--but I'm not a person to use many superlatives as are SO many golden-eared audiofools*. Fortunately, there are at least several to dozens to hundreds of variants of the same tube type for us to choose from. UNFORTUNATELY, there are at least several to dozens to hundreds of variants of the same tube type for us to choose from.
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* Probably you've read that 'this makes a huge difference', or that 'it makes the difference between night and day', or my 'favorite'--'the sound is completely different'. To the latter, I respond--OK, the system sounded spacious before and now it's closed, constricted? The bass was tuneful and extended before and now it's...what? NOT extended? Not tuneful but is ill-defined? Well, you get the idea.
.
Different tubes can change the tonal balance, the level of detail retrieved, and the level of distortion added--and probably more.
Differences in tonal balance can make the system sound forward or recessed, brighter or darker (more or less treble energy), warmer or cooler, etc. Tubes can sound more or less detailed and more or less spacious.
Personally, I find these charactersitics to be subtle but real--but I'm not a person to use many superlatives as are SO many golden-eared audiofools*. Fortunately, there are at least several to dozens to hundreds of variants of the same tube type for us to choose from. UNFORTUNATELY, there are at least several to dozens to hundreds of variants of the same tube type for us to choose from.
.
* Probably you've read that 'this makes a huge difference', or that 'it makes the difference between night and day', or my 'favorite'--'the sound is completely different'. To the latter, I respond--OK, the system sounded spacious before and now it's closed, constricted? The bass was tuneful and extended before and now it's...what? NOT extended? Not tuneful but is ill-defined? Well, you get the idea.
.