I agree with the last person posting Aleph over X. The Aleph, to my ears, has no signature whatever. I have heard the Pass X-350 on several occasions and it has a sonic signature. I own a Pass Aleph 4 and have heard most of the Aleph series including Aleph 3, 5 and 1.2. Aleph amps are some of the best amps ever made. Note that the new Pass XA series tries to marry the midrange and top end of the Aleph with the slam, dynamics and bass control of the X series. The Pass XA series currently consists of two amps of $18000 and $28000 respectively. They are much more expensive than the X series amps of equivalent power ratings. Note that the new Pass XA series tries to combine the sonic purity, midrange and top end of the Aleph with the slam, dynamics and bass control of the X series. This represents the return of Pass to manufacture of pure class A amplifiers rather than the Class AB designs of the X series in order to deliver an amp with the level of sonic purity for which the Alephs were known. All of this should give you the sense that the X series did not render the Alephs obsolete. At the used prices for which the Aleph amps can currently be purchased, they are absolutely a steal and one of the great buys in audio today.
