What's better 100w class a or 200w class ab?

Most amps that are rated for Class A operation are actually AB. They stay in Class A much longer than normal, so they refer to them as Class A rather than stating "VERY rich Class AB". Very "rich" AB amps stay in Class A for anywhere between 8 - 30 wpc ( some go a little higher ) before switching over to Class B operation for power levels beyond that point. To dissipate BIG wattage and run Class A would take MEGA heatsinking and forced air cooling if you were standing on the throttle for any amount of time. You will realize just how much heat you have pouring off of one of these amps as the ambient air temperature of the room will climb quite noticeably.

As to whether it is important that the amp stay in Class A for a long time, some people say that Class B sounds better. While there are technical reasons as to why this would be impossible, my ears tell me that the higher the amp is biased, the better it sounds. Keep in mind that high bias amps typically require very long warm up periods to sound their best and typically perform optimally after being on for quite some time. As such, i don't shut my amps off as i've found them to really "sing" after being on for about 2 - 3 days or so.

As to your original question, unless the circuits were identical and you knew the point that the amp switched from Class A to B, there really is no "best" answer. Sean
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An amp with very high rail voltages that is capable of sustained amounts of high current would be best and most versatile. Some loads REQUIRE both aspects for best results. Such a design requires quite a bit of heatsink area though and is not cheap to produce in terms of transformer and amount of output devices. Don't under-estimate the importance of rail voltage in a power amp and simply look for something that is supposedly "high current". You might find something that sounds good, but it would limit what it could be used with in terms of future speaker purchases. Sean
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Thanks for the lesson in physics Bear. You did a wonderful job on that one : ) Besides that, i can see why you are called "Bear". You must be big as a grizzly to tote amps like that around. Those things had better have some hellaciously well made and anchored rack handles is all that i can say. : )

Ozfly: I would say that somewhere around 45 - 60 volts would be about average for most amps. Some may go marginally higher than that. When you start getting up around 80 - 90 volts or so, i would consider that a high rail voltage. Some of the newer switching type amps actually go up quite a bit higher than that from what i've read. Sean
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