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Two amps, one pure class A, other A/B

Here is the question.
You have two amps from the same manufacturer, they have the same power supply, the same transformers, most likely the same output transistors.
One is biased as pure class A and outputs 50W.
The other is biased as class A/B and outputs 150W.
If 50W amp clearly cannot drive your speakers (you have flabby bass), will the 150W one do the better job, considering the only difference is bias?
sashav
newbee
4,093 posts
 
IMHO, flabby bass is not dependent on power output. IF everything except power output are the same you'd still have flabby bass. With the 50wt'er you might have less bass, on the level of 4 to 5 db, but not tighter bass. And the 50 wt'er might be smoother.
rlawry
414 posts
 
If you have the same power supply and components I would expect the bass to be similar. Typically an amp biased into Class A will produce about 4 times the power in Class AB. I remember some Forte amps that had the same components but the Class A amp made 50 watts and the AB made 200 watts. I have two different Essence amps, one a pair of monoblocks heavily biased into Class A and the other a stereo amp running much cooler in Class AB. The A amp produces better bass mainly because it has a much bigger power supply. It also is more full-sounding and has better dynamics. The AB amp has more speed and detail.
tvad
9,467 posts
 
The flabby bass is most likely a result of an impedance mismatch. If the two amps have similar impedance curves in the bass region, then the flabbiness will be apparent with both amplifiers when driving the same speakers.

IMO.
saki70
853 posts
 
Sashav I apologize for hijacking your thread .

Can anyone describe the difference , in sound , between class A and class B ?

Thank you .
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