what makes a tube sound the way it does?


I have a tube pre and know that tubes sound diffrent but was curious to know exactly how and why they can manipulate the sound (sometimes dratically) anyway,,,thanks
thinkinstereo
Tubes overload easily. Tubes sound nice in overload. They act like a compressor. They add lots of the right kinds of harmonic distortion during overload and this can make a pleasing sound. It can even make the music more audible to our ears/brain ( we are very susceptible to discerning harmonics)

Solid state can be more robust and play at much higher levels with better linearity = more accurate. However, when Solid State clips it sounds awful and immediately becomes much less accurate.

To get good sound with Solid State you need to absolutely ensure no clipping. (i.e. requires a very powerful amplifier and an easy load). A good linear tube amp will actually sound almost identical to solid state up until the point it clips (often this occurs at very modest levels due to transient peaks) at which point it gives that famous "tube sound".
Tubes are used a lot in recording studios for miking and also for mastering....that pleasing tube sound can improve a "thin" sounding mix...it can also act as a limiter to reduce dynamic range on a studio mix in a very elegant way. Studio miking with solid state can prove to be a challenge due to the shear dynamic range involved...as already mentioned a tube amp recording a mike will clip nicely if the sound goes out of range whilst a SS amp will sound awful as it clips....so tube amps offer advantages if you don't get the gains correct or the mike is placed too close to the instrument.