Mitchb, the Pass X-.5 series is a significant improvement over the original X amps. I had a pair of Aleph 1 monoblocks and when I compared them to the X-amps I found that the X-series was more detailed, had a better/tighter bottom end, but were somewhat "cold" sounding and not as musical as the Alephs.
With the X-.5 series you get what the Alephs offered with the details, slam, and dynamics of the X-series. I now run a 350.5 in my system, it replaced a great amp in its own right an Edge NL-10, and find it to be terrific in its performance.
By the way, must Pass Lab fans agree that in the X-series the best sounding amp was the 250 not the 350. The 250.5 gives you about 20 watts of class A before going into class A/B, the 350.5 gives about 50 watts of class A before going into class A/B. Both give a few watts of single ended class A before going into Class A, and those first single ended class A watts make a big difference.
With the X-.5 series you get what the Alephs offered with the details, slam, and dynamics of the X-series. I now run a 350.5 in my system, it replaced a great amp in its own right an Edge NL-10, and find it to be terrific in its performance.
By the way, must Pass Lab fans agree that in the X-series the best sounding amp was the 250 not the 350. The 250.5 gives you about 20 watts of class A before going into class A/B, the 350.5 gives about 50 watts of class A before going into class A/B. Both give a few watts of single ended class A before going into Class A, and those first single ended class A watts make a big difference.