Tvad is sort of correct. IMHE in any given amp that allows switching Triode is usually less aggressive, up-front, etc. Some times the sound stage is more recessive and the tone softer (the old Mesa Baron was very illustrative of this having 4 stages from all pentode to all triode which were comparable on the fly. You could hear immediately the difference)
But, I wouldn't go so far as to proclaim that a Triode amp will always 'sound' better, different perhaps, when actually connected to your speakers. You might just end up with warm mush! You've got to hear them with your speakers in your environment before you reach any conclusion.
FWIW, you mentioned the Primaluna and the Cary amps. I have both, although my Carys are the CAD50B's. IMHO, with my stuff, the Primalunas in ultralinear are both more listenable and linear than the Cary's (in triode) and these particular Carys in ultralinear mode are, for me, unlistenable.
Be careful.
But, I wouldn't go so far as to proclaim that a Triode amp will always 'sound' better, different perhaps, when actually connected to your speakers. You might just end up with warm mush! You've got to hear them with your speakers in your environment before you reach any conclusion.
FWIW, you mentioned the Primaluna and the Cary amps. I have both, although my Carys are the CAD50B's. IMHO, with my stuff, the Primalunas in ultralinear are both more listenable and linear than the Cary's (in triode) and these particular Carys in ultralinear mode are, for me, unlistenable.
Be careful.