Pure class A amplifiers = "slow" amplifiers?

Class A amps are not slower or faster than class A/B and do not inherantly have more distortion. Class A actually potentially has less distortion because the active device is biased in a manner so that it conducts the through the entire cycle of the input signal. Of course can drive the active device too far in one direction or the other and end up with a distorted waveform - distorted sound. A Class A device avoids the distortion caused when you process something less than the entire cycle with one active device and the remainder with a second active device, because the point where the conduction crosses over causes a glitch. However, this is not really a problem if the system is properly designed. Why would anyone want to use less than Class A topology ? Because you save on the size of the active devices, if you are only conducting current half the time you create less heat and can use a lower wattage component. A well designed CLass A should sound no better or no worse and no different than a well designed Class A/B. Now there are a host of reasons that one amplifier may sound different than another but whether the design is CLass A or Class A/B is too limited of a criterion to say how an amp will sound or how well it will be able to drive a load.

Guidocorona, my impression of real Krell amps (pure class A power only amps, no HT or integrateds) is that they are warm, deep, and excell at both micro and macro dynamics. I'm a big fan.

In my opinion dynamic range is more loudspeaker related than amplifier. For if you rely on massive power to get dynamics you are forcing your loudspeakers to perform, requiring massive cone excursions and much heat to crossover parts and voice coils all detrimental to sound quality and loudspeaker life span. I find loudspeakers that are efficent and need little power to provide far far better dynamic range and speed than conventional loudspeakers that need huge power just to sqeak out limited SPL. Since the driver cones are hardly moving in hi-eff designs they reveal hidden details that are lost to massive excurtion designs. Plus hi-eff are at ease at almost all SPL levels since these designs are never forced or pushed they dont heat up as much or sound fatiging like convetional designs do at HI-SPL. Once you hear proper replicated dynamic range conventional loudspeakers with massive power sound slow and compressed. CLass A is not the cause at all its the loudspeakers.

Johnk...Although Maggies aren't high efficiency speakers, they do have very small diaphragm excursion, and I believe this may be a lot of the reason they sound good. When I designed a cone driver subwoofer system to go with my Maggies a prime criteria was minimal cone excursion. What happens to the typical subwoofer cone is obscene!! I ended up with three subwoofer systems, for my three front channels, each including a 15" driver and a 12" driver. I get very strong bass with quite modest cone excursion.

I spent over a decade with dipoles most models including maggies. For me HI-EFF been the better sound. Now with HI-EFF ribbons about this frees up design. I have a few med to hi-eff hybrid ribbon loudspeakers about. Gives the best of both worlds. No need for HI-Eff to be all horn but still my mains for now are giant 3 way front horns. Ive built a few bass systems for Maggie, ML, SL, Quad owners and the fostex 31.5in is the best I heard matched to 20.1 3.6 and other electrostatics.31.5 can be used in OB so dipole bass. But very large and costly...No free lunch. I have also used 31.5 with oris 250 fostex f200a a few dif ribbons and comp tweeters set up as OB even mid horn is dipole but -6db down over front and to me;) a good step up from the maggies and other electrostatics Ive owned mess about with for customers. I do hear why folks enjoy the maggie sound you can build good systems arround them. As with all things YMMV,and we all dont have the same tastes.