2. amps-preamps
  3. 1217171355

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
guidocorona
4,114 posts
 
Oh wow, you guys mean that I can really change the time signature on a song by getting a different amp? I always thought that Bernstein takes Dvorak a bit too slowly. . . what amp should I select to speed up playing time by about 20%?
jayarr
117 posts
 
My experience is that Class A amps provide a fuller sound which I believe is more realistic to the original performance. Class AB or Class B amps add crossover distortion when they transition from Class A to B. I believe this sounds like adding an edge to the music, especially transients, which accentuates the leading edge of the transient at the expense of the follow-thru. This sounds "sharper" or faster. However this leads to listener fatigue over time and is particularly noticable on "hot" recordings which can sound almost unlistenable in some instances. Obviously there are more variables which make an amp sound different than another one. I heard a demonstration once of amps whose only difference was at what point they transitioned to Class B i.e. at 5 watts or full Class A. Class AB sounded as I described above. I much preferred the Class A. It wasn't a night and day difference but was noticable.
audphile1's avatar
audphile1
1,368 posts
 
Guidocorona, LOL.
dave_b's avatar
dave_b
2,267 posts
 
Other than making sure your power is enough to command the A1's, maybe the accuphase pre is adding some fudge...nice sounding but not speed racer! Try a used Krell stereo amp with a KCT...should be warm and fast.
eldartford
4,262 posts
 
Guidocorona...Believe it or not audio can be speeded up without the tonal change that results from overspeeded playback...but no using a simple amplifier. It takes some digital processing.

It is a fact that our sense of hearing can recieve and understand speech faster than our tongues can wag. Alarm messages, for example to airplane pilots, can be speeded up.
More to discover