Don Pearce wrote:
On Sun, 13 May 2007 17:53:45 +0200, jaap wrote:

Don Pearce schreef:
On Sun, 13 May 2007 17:11:14 +0200, jaap wrote:

Graham Holloway schreef:
"Arny Krueger" wrote in message
. ..
"max graff" wrote in message
oups.com
Hi guys,

Pardon my lack of technical lingo but Rotel and a few
other companies have been flaunting class D power amps.
I know that class A is the best in amplification
Class AB done right is just as good, if not better.

however attaining that level at higher wattage is only
hypothetical.
Not to mention stupid.

I want to know what and how good is the supposed class D
amplification.
Current implementations seem to underperform its potential.

The biggest problem with switchmode operation letely has been keeping the
switching pulses out of the speakers. Running the switches faster is the
obvious solution, as it is easier and more practical to build high powered
filters, as the frequency being filtered out goes up.

Right now a lot of class D amplifiers seem to suffer from excessively high
output impedance near the top of the audio range.


That's probably due to the aforesaid filter.

Graham H


Make that certainly.

It's a public secret there's only a small market for better sounding
equipment. Most people don't bother because they want to hear amplified
sound and do not enjoy the quality, especially when expensive. There
lays the problem manufacturers are facing.

I think that lost something in the translation from Dutch. Could you
elaborate?

d

Alright. Being a public secret is a saying (over here) and means as much
as being common knowledge to most people.

No, I got that bit - it was all the rest that had me puzzled.

d


Look around you, probably within your family or among your friends. Most
people won't be bothered by new disk standards, color of face plates,
brand names, fourfold wiring with precious metals, quantity of
loudspeakers etcetera. It's all about enjoying the music, not how it is
reproduced.
OK, there exist a group of people running to the shop every year for the
last model but I don't think this is because they enjoy the music so
much. See my point?

Another example: TV sets. It's only for a couple of years manufacturers
are paying attention to better sound reproduction. Many of us are having
terrible reproduction quality and still enjoy the moving pictures.

Manufacturers can produce better sets but what happens if customers
don't want to spend more money on a TV or HiFi?

Jaap