Is there actually a difference?

There are, in my mind, kind of 3 amps you should listen to and see if you think they sound the same:

Parasound
Pass
Ayre

These amps to me are rather opposed to each other in terms of sound. 

If you cannot tell the difference between them, buy the cheapest one. :) 

Best,

E

Back in the early 80s, a audio enthusiast friend and myself, each had a 100W HK SS power amp and had Audible Illusions pre-amps. My speakers, at the time was the Vandy 2c and I think his was the Pioneer HPM100s. In short - our audio dealer loaned us a new little amp to bring home and try for a week - It was the 80W, PSE Studio II.
Somewhat believing Julian's stories about all SS amps sounding the same, I was expecting to hear very little, if any difference. What a surprise - in both systems, in every way, the little, PSE out performed the HKs. It was like removing a veil.
Needless to say, I picked up the PSE. Even though I went from the Vandy 2Cs to the Vandy 2Ci to the Quad ESL 63s, the PSE stayed and served me very well....Jim

I've tried various amps over the years both SS and tube. Differing amounts of watts from 60 up to 1000 depending on speaker ohms. Tried many kinds of speakers; easy to drive and some not so easy. I always found what sounded best were high current designs regardless of power output or speaker efficiency. Synergy between components is important too. My higher wattage systems never sounded as good as my lower wattage systems that were high current. Mainly a Pioneer M-22 or Threshold S/300. The other amps had higher power ratings but never sounded good. And those were the ones I had full recaps on or upgraded.

@erik_squires—Hi, Erik, your comment was of special interest to me because I think that I comprehend the thrust of your point; i.e. that these three makers each represent distinct (power amp) design approaches that are competently executed but distinctly different.

Now, I know the Parasound approach (I use their Halo A23 myself), which is basically conventional class B operation. (Yes—it's slightly "hi-biased" at very low power—so-called "class A/B" mode—but that's not a truly significant distinction.)  And I'm familiar with the Pass design concept, wherein output stages are biased for true class A operation at powers up to ~ 12-18 Watts output (on many models). But I'm NOT able to gain any meaningful information about the Ayre stuff, and I find that really frustrating!

A Personal Note: I'm an old retired guy with lots of DIY hi-fi experience, including analog circuit design and building my own pre-amps, power amps, & linear regulated power supplies. I like to know the tech stuff, and I do a lot of my own testing. (With my own instruments.)

The Ayre website is the anthesis of Parasound's site. Ayre provides only the barest of product specifications with near zero tech info. And their owner's manual downloads are pure fluff. Sure—their chassis look great and their prices are exotic—but how does one comprehend what they're doing? How does one get to appreciate Ayre's designs and learn what's going on inside? I haven't even been able to find a helpful (meaning with tech detail) review on the Ayre stuff. What do you know, and how does one find out what Ayre is doing? Any suggestions?