How Much Difference Does a More Powerful Amp Make?

Generally, an amp that doubles its output from 8 ohms to 4 ohms is a high output amp. Only very robust power supplies are able to go from 200 watts @ 8 ohms to 400 watts @ 4 ohms. An excellent solid state amp that does this is the Clayton M200, plus its output is all Class A. Occassionally they pop up for resale on Audiogon. I know, because I recently bought one at around $4,500. You won't find a better solid state amp than the Clayton. They even make a M300 with 300 watts/channel @ 8 ohms. These amps are built incredibly well and likely will last decades, due to their military spec building quality. They are plain looking, but beautifully sounding with most speakers.

An alternative solid state that is about as good as the Clayton's are the McCormack DNA-500's. Both these amps are significantly better than most of the famous named solid state amps, such as Levinson, Krell, Rowland, etc. And they are less expensive to boot.

Greg

Easy, just think the differences in horse power in a car, as you are climbing Pike's Peak.

For inefficient speakers with low impedance drops a more powerful amp can make a dramatic difference. For your average speaker you may perceive better or tighter bass and more "ease" at louder volumes. But then again you may perceive nothing different at normal listening levels and sometimes lower powered amps do indeed have better sound than their big brothers.

Amp rated at lower continuous power might have higher momentary power. Average power needed for music is only few percent of peak power unless you listen to sinewaves.

Power specifications give only general guidance but all depends on particular amp design. Chances are, when comparing amps from the same line/company, that higher rated amp will be louder but 15.7% difference in loudness might not be worth extra money.

Comparing to a car is a little misleading since 10x power is only 2x louder (exponential scale).

The point has already been made but here it is in a cute form.
If the first watt sounds bad why would you want several hundred more of them?
Quality is the key and the usual recognition that some speakers really do need high current amplification to sound best. Essentially I am just agreeing with most of the comments thus far.