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Pure class A amplifiers = "slow" amplifiers?

Hi folks, I know this is subject of controversy. In general pure class A has been regarded as the best way in solid state amplification to get the purest sound. In my experience many pure class A solid state amplifiers (Accuphase, Pass Labs, Plinius) sound "slow" and are lacking "dynamics". Do they sound that way because they have less distortion than class A/B amplifiers, I mean sometimes a signal is so pure that one is increasing the volume adjustment knob to get a louder sound. With a very pure sound it seems like music goes slower too (= psychoacoustic phenomenon).

Chris
dazzdax
mechans
2,999 posts
 
Band width and slew rate are not a function of eachother only potentially limited by one or the other parameter. In any event the slew rate is ridiculously quick, some other elements must account for percieved slowness. I don't percieve it in my class A tube amp at all. I think it is not physics but pycho acoustics with cues telling some listeners the sound is rich dense, or heavy and therefore slower.
gs5556
769 posts
 
If you're just telling us that you don't prefer the 'Class A' sound, that's understandable. Class A is not the only way to good sound or else it would be the only type of amplifier people would buy. Just because you prefer one over he other doesn't mean you're missing the bus or it's a design issue - there are plenty of A/AB's out there that outperform single-ended Class A. But then again, substituting a better amplifier shows up downstream equipment. Maybe it's the preamplifier slowing things down.
dave_b's avatar
dave_b
2,267 posts
 
What are your speakers?? Pre?? Source???
dazzdax OP
599 posts
 
Dave, I have Soundlab A-1's, Accuphase C-290V preamplifier and MBL/Accustic Arts digital front end.

Chris
stehno
1,453 posts
 
Dazzdax, there should be little or no correlation between what seems to be a slower tempo and the purity of the signal.

You are correct that the cleaner the signal the more you want to crank it because it does not sound as loud as previously. That's because we historically have associated loudness with distortion. The greater the volume the greater the distortion. So when a more pure output is generated we have a tendency to think it is not as loud.

As for slower tempo, this generally has much to do with the speed of the transistors (and perhaps other innards).

Amazing how one component made by two different manufacturers can make the tempo sound slow as molasses or lightening quick.

Always something to look out for when purchasing gear. I suggest staying far, far away from any component that you deem to be 'slow'. It's a huge step in the wrong direction as it has nothing to do with musicality no matter what other benefits the component may offer.

-IMO
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