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 however attaining
that level at higher wattage is only hypothetical.

I want to know what and how good is the supposed class D
amplification.

Regards

Max.

On 11 May 2007 13:07:52 -0700, max graff wrote:

I know that class A is the best in amplification

How do you know that?

On 11 May 2007 13:07:52 -0700, max graff wrote:

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 however attaining
that level at higher wattage is only hypothetical.


No, class B is every bit as good as class A. In fact better from many
points of view.

I want to know what and how good is the supposed class D
amplification.


What do you mean "supposed" class D? I have an "actual" class D amp in
a subwoofer. It is very good.

d

--
Pearce Consulting
http://www.pearce.uk.com

On May 11, 10:07 pm, max graff wrote:
I know that class A is the best in amplification however attaining
that level at higher wattage is only hypothetical.

This is not a wise statement. I am sure you will find quite a few
readers prepared to bet you cannot hear the difference between a
reasonable class A amplifier and a reasonable class AB driving a
reasonable loudspeaker.

I want to know what and how good is the supposed class D
amplification.

This is a good question (assuming "digital" amplifier of whatever
class and audibly neutral under normal conditions) . I do not know the
answer and given the absence of any reliable consumer audio
publications and the absence of reasonable specifications from the
manufacturers it is not obvious to me where to look for an answer.

Obviously one could perform experiments oneself but that would imply a
pretty awesome loss of basic technical knowledge about the performance
of consumer audio in these broadband www days.

Anyone?

"max graff" wrote in message
oups.com...
Hi guys,


** Typical Google / Hotmail troll opening.


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 however attaining
that level at higher wattage is only hypothetical.

I want to know what and how good is the supposed class D
amplification.


** Idiot question.

The questions should be:


Q. How bad are the worst examples of class D ?

A. Atrocious.


Q. How good are the bests examples of class D

A. Good as any hi-fi amp made.


Q. What is the motive for makers to use class D ?

A. Lower cost to make multi-channel amps.


Q. How do marketing pukes regard class D ?

A. A great new way to separate the terminally gullible from their money.





........ Phil

"Phil Allison" wrote in message
...


** Typical Google / Hotmail troll opening.

snipped garbage

....... Phil

Typical Philthy Analson reply! Then to be followed up by
more personal abuse and the *predictable* usual, vile
insults.

TT

"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 however
attaining
that level at higher wattage is only hypothetical.

I want to know what and how good is the supposed class D
amplification.

Regards

Max.


Both Bel Canto and Halcro use these PWM (Pulse Width
Modulation) amps. Do some more research yourself and then
go and have a listen and make up your own mind.

Cheers TT

"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.

"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

honestguvnor schreef:
On May 11, 10:07 pm, max graff wrote:
I know that class A is the best in amplification however attaining
that level at higher wattage is only hypothetical.

This is not a wise statement. I am sure you will find quite a few
readers prepared to bet you cannot hear the difference between a
reasonable class A amplifier and a reasonable class AB driving a
reasonable loudspeaker.

I want to know what and how good is the supposed class D
amplification.

This is a good question (assuming "digital" amplifier of whatever
class and audibly neutral under normal conditions) . I do not know the
answer and given the absence of any reliable consumer audio
publications and the absence of reasonable specifications from the
manufacturers it is not obvious to me where to look for an answer.

Obviously one could perform experiments oneself but that would imply a
pretty awesome loss of basic technical knowledge about the performance
of consumer audio in these broadband www days.

Anyone?


Just an opinion: history shows that despite 'progress' amplification
quality diminishes every decade. Don't believe you can't do without this
new class. A good system dating from 1960 or 1970 or 1980 will beat any
plastic rubbish -whatever class- dating from 2007.

The other day I demonstrated a nice turntable setup to someone who had
listened solely to digital audio. She was surprised by the reality
coming from old gear, despite S/N THD and whatever cyphers modern stuff
tries to sell to the public.