2. amps-preamps
  3. 1090768416

How much Classe does a guy need?

I posted this in the speaker section but have moved it over to here.

The Classe does look like the kind of match Im looking for. Compared to the Krell KAV-250a. I was looking at the Classe would seem to be more musical and warmer. Which is what i prefer and will take an anylitical hit for that. The reviews of them mated to B&W CDM9s(similar to 703s)were favorable.
Theres alot of choice in the used Classe amp market. Now my speakers are rated at 200watts. The 200/201 and the 300/301 Classe amps are at 200 and 300 watts respectivly. Is over rating the speakers advisable? I was under the impression that ratings on speakers were at a given distorion for the max power. Therefore the cleaner the signal the more you could get away with over powering them. But also have to consider the peaks would be higher as well. Also under the impression that a 300 watt amp would be more dynamic as it wouldnt have to strain on producing enough power for dynamic passages(source has a dynamic range of 112db).

The cost for those amps range from $1,300 for a 200, $1,600 or $1,800 for a 201(1,800 is one with side heat sinks, later model), $1900 for a 300 and finally $2500 for a 301.

Would there be a useable diffrence between the 200 and 300 watt versions(i do listen at loud levels often)? If anyone has heard these amps id like to hear what if any diffrence in the sound was.

Once amps get a little older >5 yrs do they need new caps etc or is the life of them longer? In other words is there a point where an amp is getting a little old and one should factor in a rebuild.

Thanks
bozzy

Showing 2 responses by morbius396c

morbius396c
134 posts
 
Bozzy,

Don't worry about "overpowering" your speakers - you're more
likely to cause damage by "underpowering" them.

The rating on the speaker is how much power they can dissipate.

The power rating on the amp is how much it can put out cleanly.

However, you don't have to use all the power of a high power
amp. If it takes 25 watts to power your speakers to a given
sound pressure level - it doesn't matter to the speakers
whether that power is being delivered by a 50 watt amp or
a 500 watt amp.

However, for the amp - it is better to have more headroom -
power above that required.

If you have to transport a heavy weight up the stairs - who
do you want to do it - a child who can lift the weight - but
just barely - or a guy who works as a piano mover?

The more powerful amp can deliver the power more cleanly -
with less distortion on peaks - than can the lesser powered
amp.

For a given sound level, you are not dissipating any more
power in your speakers, just because the amp is more powerful.

Dr. Gregory Greenman
Physicist
morbius396c
134 posts
 
Bozzy,

Most of the energy in music is in the bass, and very little in
the treble. Therefore, when your speaker is rated to handle
200 watts - it is really the woofer that can handle 200 watts.
The tweeter may only handle 10 watts.

When an amp clips - the top of the wave is cut off or "clipped"
off. That turns a sine wave into something that is almost
like a square wave.

If you study mathematics - you may be familiar with what is
called a "Fourier Series". Essentially any periodic wave
can be decomposed into a bunch of sine waves of various
frequencies - including a square wave. In order to get the
sharp corners of the square wave - the Fourier series that
makes up the square wave has a lot of high frequency waves
in it.

When the amp clips, and produces a near square wave - that
square wave has a lot of high frequency or treble frequencies
in it.

The speaker's crossover will route those high frequencies to
the tweeter. So even though the amp is putting out 200 watts
or less - which the woofer can handle - you have more than
10 watts of high frequency energy that the tweeters can't
handle. So as you point out - it's the tweeters that get
fried.

That's why the underpowered amp is bad for your speakers.
If the amp is too underpowered - you may exceed its capability
at reasonable listening levels.

The high power amp can certainly fry your speakers too - but
only if you really crank up the volume.

As long as you listen to music at levels that are within the
capabilities of your speaker - then you won't have trouble.

The high power amp will not be putting any more power into
your speakers than a lesser powered amp for the same volume
level.

Dr. Gregory Greenman
Physicist
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