I used to have Aleph 0 (75 WPC, 3 gain stages). Now, I own both Aleph 2 and X-600. They are all excellent power amps.
Some facts:
Aleph 0: 75WPC, mono blocks, 3 gain stages.
Alpeh 5: 60WPC, stereo
Aleph 2: 100WPC, mono blocks, power consumption 300 watts for each (600 total). One transformer for each.
Aleph 4: 100WPC, stereo, power consumption 500 watts. One bigger transformer (I believe) for both channels.
Not sure why Pass Labs will release Aleph 4 after Aleph 2, since they are both 100 WPC, the same design and same grade of parts and I don't know which model is better. Maybe just to reduce some cost without sacrificing the sonic performance for marketing purpose.
Some facts:
Aleph 0: 75WPC, mono blocks, 3 gain stages.
Alpeh 5: 60WPC, stereo
Aleph 2: 100WPC, mono blocks, power consumption 300 watts for each (600 total). One transformer for each.
Aleph 4: 100WPC, stereo, power consumption 500 watts. One bigger transformer (I believe) for both channels.
Not sure why Pass Labs will release Aleph 4 after Aleph 2, since they are both 100 WPC, the same design and same grade of parts and I don't know which model is better. Maybe just to reduce some cost without sacrificing the sonic performance for marketing purpose.