Pass Labs xa - .5 amps


Has anyone compared the new Pass XA-30.5 stereo amp to the XA-60.5 mono amps? Interested to hear your impressions. I am considering one (or two) these for use with my ML Vantage speakers. Thanks.

Bob R.
rmrobinson1957
AFAIK there is no reason to think that any competently designed class a amp sliding into ab will damage speakers. The amount of class a delivered depends upon the bias current. Read Nelson Pass's paper on the subject on his web site. For high output solid state amps the inherent inefficiency of the design, however, requires huge power supplies, lots of heat production and large heavy heat sinks. Any manufacturer of a high output solid state " pure class a " amp which does not exhibit these characteristics is indeed exaggerating its capabilities. Reasons to choose ab over pure a include the desire for a small cool energy efficient amp or the need for very high output ( >500 watts) which is not very practical to achieve using class a. - Jim
Aldavis, I'm not sure if your responding to my post or not. If so, I don't believe that I suggested that a Class A amp sliding into class AB would damage speakers. What I was suggesting is that over driving an amp could damage speakers.
Thanks for the clarification. I misunderstood. If by overdriving you mean clipping I would say that class a amps are not more prone to this.
Aldavis, it might be argued that class A amps might be more prone to clipping than class AB amps in that it's easier and less expensive to provide the neccessary power to avoid clipping with class AB than with class A operation. But, honestly, this is just an academic argument.
It appears that a few people on this board are looking for non-commercial bias and honest opinion about how to choose a Pass amplifier. I would suggest that you review messages previously written about Pass XA.5 and X.5 series on this board, find ways to actually audition the amp. before consider buying, and call Pass Lab to get their advice on what amp to get given your existing stereo equipment. I did have to do my homework before buying anything. My few observations and some common sense are that: (1) People who are happy with XA30.5 tend to have smaller speakers; (2) Pass Lab personnel themselves when called upon are too proud to not give you what's right as opposed to what's profitable to them; (3) Class A amplifiers will heat up and will require some warming up time if you want good sound, but at least the XA60.5 of mine don't burn your hand like some other amp. would have; (4) All amp. regarding classification will go into clipping if you drive them that hard, but why would anybody want an amp. under-rated for the rest of their equipment? I can only tell you that the XA60.5 can certainly run enough full-size speakers, along with previously mentioned perks. As to the XA30.5, you must do your own homework, and especially don't just listen to anybody.