What Class A is better? SUGDEN FPA-4 or PASS LABS XA-25


I`d like experiences of the gurus.

Thanks
sacresta

@mattmiller 

 

Oh I don't know, just the inventor of the first Class A circuit design. If it weren't for Sugden, it's more like WHO IS PASS? 

 

Some of the folks in this thread or clearly dropping in to be post what they are fan-boys of which is fine assuming you know what the hell you are talking about. Not having heard Sugden, or looking at pictures to make judgements on how something sounds @georgehifi is ridiculous. 

Oh I don't know, just the inventor of the first Class A circuit design. If it weren't for Sugden, it's more like WHO IS PASS? 

Class A operation goes back to the 1920s.

People need to be aware that the Sugden class A amps have higher output impedance /lower damping factor than most  SS amps.They are medium for these traits wheraes most SS amps have low output impedance and high damping.So electrically they operate more like a push pull tube amp.To sound their best they need to be matched with speakers that do not dip too low in impedance-genuine 8 ohm speakers rather than 4 ohm.They are an especially good match with classic BBC and Tannoy speakers that tend to be higher impedance and which can sound overdamped by most SS amps.So when some people say they sound really good and others not so good that is probably just  a reflection of speaker matching variables.Given the right speakers they can sound fantastic.