Class A amps


I've read a few articles on class A amps but still don't have a good understanding of how it affects sound quality. I've even seen amps which can be swithced into class A mode or AB. Does anyone have experience with this type of unit? Does class A have a true audible advantage or can it be detected only by test instruments? If it is audible, in what resepects? Thanks, Rick M.
mili224

Showing 2 responses by geof3

@invalid, correct. Pass’ high end amps, (Pass Labs brand) whether class A or AB are the high powered amps. The low wattage amps (either type) are considered the entry level. 
@georgehifi… every single thread around this topic you bring up Wilson Alexias. Every, single, one. You describe the load of the Alexia as a 1 ohm load etc etc, and basically anything but a bi-polar amp, namely a Gryphon, has little to no chance of driving them. Your assertion is based on a discussion you had with John Atkinson on the original Alexia tests where he showed the load just under 2 ohms at 80hz with a -45° phase angle. Challenging load, but not crazy, and it is the load as specified by Wilson. However, you mentioned another test (that you pull your figures from) as the “evil” load you ALWAYS mention. Perhaps you should go back and read that original article where John challenges and disproves this test and states why. You failed to answer that post in the article, yet you continue to drive the narrative. Overall, I could really careless, but others might look to this, not read the article and thus not buy or perhaps overlook the Alexia. Time to pick another whipping post speaker. BTW, my Alexias are driven with Pass XA60.5’s currently, and not until about 90db does the needle even begin to fluctuate showing the amp reaching into the AB realm. The amps cruise along running about 50°c and don’t even blink. The Alexia, at 90db efficiency do require a bit of grunt, but are not the near impossible load you assert.