Audio Hungary - Qualiton A50 vs A75

My experience is that the sonic advantage of class A is so marginal that it doesn’t justify the downsides: power consumption and limited headroom. 

I currently own a solid state amp that is allegedly 100 WPC of pure class A before any switching to class B. If I strain to hear a difference, it is ever so slightly smoother than my 300 WPC class AB (≈3 watts class A) amplifier. The 300 watt amplifier sounds significantly better overall because it has an ease of presentation the class A amp cannot match (headroom for dynamic swings). Any crossover distortion with the class AB amp is inaudible to my ears. Suffice to say I prefer my AB amp. 

That said, if the difference between those two amplifiers is a mere 25 watts as the model names suggest, the difference in headroom is negligible and you might as well choose the class A version, especially if you have efficient speakers and don’t mind the hit to your power bill. 
 

Regarding power consumption, on any given week that I run my class A amp for a good few hours or more, I notice a significant increase in my metered usage. The effect on the power bill as a function of percentage is not negligible. 

@kojo123 The a50i was marketed as a 'pure' (manufacturer's emphasis, not mine :)) class A amplifier up to 50 watts. In all their marketing material, it never mentioned switching to AB prior to the rated specs. In fact, most advertising made a point to highlight that it was a class A amp. 

Either way, it is a terrific amplifier. It's one of the few pieces of equipment I regret selling. In fact, if and when I set up my second home office system, I might find a used a50i once again. I might be in the minority, but there are quite a few of us who prefer class A and are easily able to distinguish between A and AB. I'm sure the hassle is not worth to some, but to me and a few other likeminded audiophiles, a well implemented class A is worth every penny.

I have not heard the a75 personally, but I know a guy who moved up from a50 to a75 and he said it was not much of an improvement. The fit and finish is also not at the same level as the a50i. I'm a sucker for the polished chrome look so maybe I'm biased.

If I were you, I would save some $$$ and buy a used a50i. If you don't already have subwoofers, you can spend the savings towards one or two subs.

Thank you Gents for support! 

Regarding A50i, im aware that almost everywhere is written, that this is pure class A. As it was on old Audio Hungary website (one dealer checked for me today). 

I started to diging topic, since it is very unlikely that A75 might be pure A class. Going forward, there is no such information on new Qualiton website. Ultimately, AB class was both for A50 and A75 was confirmed by Qualiton directly.

Cheers!