class a-whats the point?

[admin_exported]

ive just spent the last two days listening to the marantz pm7200 amp,firstly in class a(25w) and then class ab(up to 95w).i kept the volume dial at the same setting(9 oclock if you imagine the volume dial as a clock face) and concentrated on 5 different pieces of music playing each a lot of times in the two different modes.the conclusion that ive come to is that in class a the music sounds a lot flater while in class ab the music sounds thicker and richer,almost as if someone has just switched on a loundness button only there isnt one.also what is the point in listening to this amp in class a when youre condensing the music down into a 25w soundworld when this amp has the 95w capacity? im not saying play your music at 95w because its more than loud enough at the setting ive used,but surely if somebody was continually using it in the class a mode it would have been better for them in the first place to have bought an amp with a 25-30w capacity rather than one with a 95w capacity?surely you must be losing something by restricting it.its rather like doing 30 in a ferrari when you could be doing 90.your thoughts please...

 

[Anonymous]

The Marantz is not an ideal example of what Class A is about because of the compromises involved in allowing it to switch between the two (and remember it needs to be switched off between changes otherwise it stays in AB). True Class A amps (that only run in Class A) are an acquired taste. Systems need to be built around their usually limited power output and they generate huge amounts of heat. The flipside is a well balanced Class A system has a naturalness and open sound that is very hard to beat or equal with all but the most extraordinary AB equipment. A sympathetic system built around a Sugden A21 or if you can find one, an example of Japanese Class A from Pioneer, Luxman or Accuphase is a lesson in music making. The downside is that unless you have very sensitive speakers or a leviathan of an amp (think Sugden Masterclass, Electrocompaniet or Krell) the dynamic peaks that AB amps don't raise a sweat over become something of a challenge for Class A.

 

[Anonymous]

Class A suits some speakers more than others, a factor to be considered.

 

[Anonymous]

Super-Class A is where it's at! The ultimate - non of that switching stuff!

 

[JoelSim]

Class A is perfect when your central heating sin't working

 

[Anonymous]

[quote user="JoelSim"]Class A is perfect when your central heating sin't working[/quote]

Remember the old Marantz PM-94? That got HOT HOT HOT! SO HOT infact that somebody demonstrated that it would only take 20 minutes to cook an egg on it!

 

[Thaiman]

Most of classic products are "class A" design

Krell KSA series, Musical Fidelity MA-50, Conrad Johnson PR-10, EAR 509 ....etc etc.