If i used a preamp that has a headphone output .. is the sound the same direct into the preamp than preamp to mixer (XLR) and plug headphone in the mixer ?
Bedroom rock star :

- Gibson Les paul Standard 2001 Honeyburst .
- Agile 3200 Slim
My instincts say no, partly because the headphone out will have some kind of filter to compensate for speaker simulation on it, where the XLR will be a balanced proper output. Someone please correct me if I am wrong though.
Epi Explorer
Squier Vintage Modified Tele

Dunlop Crybaby (modded)
TC Polytune
Marshall ED-1
Vexter Box of Rock
Harmonic Jerkulator (home made)
Boss CE-3
Line6 Echo Park

Modified Traynor YCV40
Fender Super Champ XD