The Pass Aleph series amplifiers sound quite different from the current X series. I have owned both and can recommend both, though my preference is for the new stuff.
In the Aleph series, the 0s are from the original 3-gain stage design, whereas the Alephs 3, 4, 5 and I believe the 2 are from the later 2-gain stage design.
In the Aleph series, the 0s are from the original 3-gain stage design, whereas the Alephs 3, 4, 5 and I believe the 2 are from the later 2-gain stage design.