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?

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.

jaap wrote:
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.

Interesting opinion, but what is it based on? Modern systems are louder,
distort less, have wider bandwidth and less noise than 1960s or 1970s
systems, but haven't improved to any great extent since the '80s.
However, they certainly haven't diminished.



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.

Of course old gear is capable of sounding good, but so is modern gear,
and for relatively much less money, size, power consumption and improved
reliability.

S.
--
http://audiopages.googlepages.com

Serge Auckland wrote:
jaap wrote:
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.

Interesting opinion, but what is it based on? Modern systems are louder,
distort less, have wider bandwidth and less noise than 1960s or 1970s
systems, but haven't improved to any great extent since the '80s.
However, they certainly haven't diminished.



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.

Of course old gear is capable of sounding good, but so is modern gear,
and for relatively much less money, size, power consumption and improved
reliability.

S.

Hi Serge,

My opinion is based on human hearing and not on the momentary
technological approach from a-musical tecchies. I got to this opinion
speaking with fellow musiclovers, who share a passion for the best
obtainable. Most got tube amps under 5W per channel, some built their
own, often accomplished by single driver speakers.

Modern equipment is expensive compared to good used quality parts. The
latter will probably outlast the former by decades because of the poor
quality parts used these days.
Agreed, ancient low budget equipment belongs on the scrapyard.

Jaap

jaap wrote:
Serge Auckland wrote:
jaap wrote:
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.

Interesting opinion, but what is it based on? Modern systems are
louder, distort less, have wider bandwidth and less noise than 1960s
or 1970s systems, but haven't improved to any great extent since the
'80s. However, they certainly haven't diminished.



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.

Of course old gear is capable of sounding good, but so is modern gear,
and for relatively much less money, size, power consumption and
improved reliability.

S.

Hi Serge,

My opinion is based on human hearing and not on the momentary
technological approach from a-musical tecchies. I got to this opinion
speaking with fellow musiclovers, who share a passion for the best
obtainable. Most got tube amps under 5W per channel, some built their
own, often accomplished by single driver speakers.

So they're not into high fidelity ;-)


Modern equipment is expensive compared to good used quality parts. The
latter will probably outlast the former by decades because of the poor
quality parts used these days.
Agreed, ancient low budget equipment belongs on the scrapyard.

Jaap

New equipment can cost more than used, although some of the prices being
paid for old technologies like SETs and paper-coned full-range drivers
are a lot higher than you can buy perfectly decent modern stuff for.
However, if you compare what an amplifier costs now and what a similar
spec cost in 1960 or 1970, it's an awful lot cheaper now.

Many of us, me included, like vintage gear, in the same way I like
vintage cars, fountain pens and mechanical watches, but I don't expect
(or get) the same standard of performance as I do from my modern stuff.

S.




--
http://audiopages.googlepages.com

In article l, jaap
wrote:
Serge Auckland wrote:
jaap wrote:



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.

Interesting opinion, but what is it based on? Modern systems are
louder, distort less, have wider bandwidth and less noise than 1960s
or 1970s systems, but haven't improved to any great extent since the
'80s. However, they certainly haven't diminished.

Well, I'd be happy to believe that amplifiers have 'deminished' over the
decades. I am still enjoying using the amps I designs 20+ years ago. So it
would be smug to assume that newer ones were all poorer. However I suspect
the 'opinion' remains an 'opinion' for the simple reason that it isn't a
'fact'. ;-


Hi Serge,

My opinion is based on human hearing and not on the momentary
technological approach from a-musical tecchies.

Strangely, I also based my opinions on this on 'human hearing'. Just that
my experiences clearly differ from yours, I suppose. :-)


I got to this opinion speaking with fellow musiclovers, who share a
passion for the best obtainable. Most got tube amps under 5W per
channel, some built their own, often accomplished by single driver
speakers.

Ah, so 'the best' means soft clipping to alter the sounds in ways you
prefer. I see. Do you also regard high output impedance as useful to alter
the frequency response in ways you like? :-)

Slainte,

Jim

--
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Audio Misc http://www.st-and.demon.co.uk/AudioMisc/index.html
Armstrong Audio http://www.st-and.demon.co.uk/Audio/armstrong.html
Barbirolli Soc. http://www.st-and.demon.co.uk/JBSoc/JBSoc.html

In article l,
jaap wrote:
My opinion is based on human hearing and not on the momentary
technological approach from a-musical tecchies. I got to this opinion
speaking with fellow musiclovers, who share a passion for the best
obtainable. Most got tube amps under 5W per channel, some built their
own, often accomplished by single driver speakers.

Then they're certainly not interested in 'the best obtainable'. They just
prefer the colouration and distortions such a system *adds* to any signal.
In any tests comparing live to recorded such a system will come well down
the list. A sort of Picasso versus photograph thing.

--
*How come you never hear about gruntled employees? *

Dave Plowman London SW
To e-mail, change noise into sound.