2. amps-preamps
  3. 1270775639

Pass Labs A/B amps vs Class A amp and Actual Power

Dumb question; how can you compare the actual power or ability of an amp to drive a tough load (such as a Magnepan) when looking at a Pass Labs A/B design such as the X250.5 or X350.5 vs one of the full class A amps like the XA60.5 and XA100.5? For example, which amps would (from a standpoint of just pure power/grunt) drive 3.6's better, an X350.5 or a XA60.5?
stickman451
unsound
7,333 posts
 
Stickman, are you sure that the XA 100.5 maintains Class A bias (or something to that effect, as there has been discussion here on the technical classification as to whether Class A/AB and Class AB amps technically deliver any Class A bias(?))or is the Class A Bias reduced and the Class AB increased as it doubles down?
stickman451 OP
553 posts
 
I'm pretty sure that Pass Labs told me that all of their XA.5 and X.5 amps 'double-down', so an XA100.5 would give you 200 watts of Class A into a 4 ohm load... Pretty sure I heard them say that exactly...
stickman451 OP
553 posts
 
Teajay or other 20.1 owners - in your opinion, what is the absolute minimum room width that will work with a Magnepan 20.1?
unsound
7,333 posts
 
Stickman, many if not most amps that are touted as doubling down Class A amps actually halve their Class A out-put as they do so. Including Nelson Pass' previous Threshold designs:
http://www.stereophile.com/solidpoweramps/1290thresh/index1.html
stickman451 OP
553 posts
 
For me it's probably a mute point; the XA100.5 is most likely more than I can/would spend even at used prices...
More to discover