Pass X 150 and X150.5 differences please.

Hello everyone,

I am looking for anyones experiences of sound improvement of the latest- 2 years and newer x 150.5s.
I own an old x 150 who was a Pass employee's personal unit and wonder if I should sell it and buy the latest. This is what I know; the very first 150.5 versions differed by the meter only. A year down later they revamped the amp completely- new output devices and more, bigger, quieter power supplies, resulting in 10db noise reduction, etc.

Bottom line; numbers don't always speak in high end- is it a better sounding amp and if so what should I expect?

Thank you very much for your advise. I've been out of the big Pass game for a while, just kept the 150.
My x600- x350- x1- x0.2 were all sold. I've kept the 150 for audiophile parties- loud rock- and studio work.
I owned both at different times..The X150 for a very short time.Sounded too SS and lacked overall involvement for me.In short, too sterile,IMO..The X150.5 however I really enjoyed,Greater detail,wider soundstage with less of a sterile SS sound...I think everyone that listens to Pass agrees the X.5 series is well worth the extra money..Its really easier if you just take a listen and judge for yourself..
I have owned the X350 and currently own the X150.5.I really thought it would just be a stop gap until I found an X350.5 but..

The X150.5 really is a much better sounding amp in every respect than the X350-more detail,dynamics,sparkle and slightly more warmth in the midrange.

It drives my Revels with ease and is quite friendly to the mains,the X350 draws 650w idle which is what the Smaller amp does at max!
I think you will consistently get similar replies. The .5 sound better to most people for the reasons stated above.