[Karl Uppiano]

**Like I said, It has been done before, with variable success rates.
In reality, however, the BEST amplification is still high bias Class
A/B, with no dodgy power supply rail switching schemes. Such schemes
are really only ways to cut costs.

It's done to cut down dissipation primarily. In high power amplifiers
this eventually become a very significant issue and might otherwise
require impossibly large heatsinks. It's an excellent way of improving
efficiency.

Graham


netkkkkopin ggarbage

It is? Why? All engineering is a compromise. Engineers are always
constrained by cost, size, performance, reliability, complexity, esthetics,
marketing B.S. When cost is no object, as is often the case for high-end
hi-fi enthusiasts, that removes a huge constraint.

[Bertie the Bunyip]

"Karl Uppiano" wrote in
news:NVxYg.706$AR6.264@trndny02:

**Like I said, It has been done before, with variable success
rates. In reality, however, the BEST amplification is still high
bias Class A/B, with no dodgy power supply rail switching schemes.
Such schemes are really only ways to cut costs.

It's done to cut down dissipation primarily. In high power
amplifiers this eventually become a very significant issue and might
otherwise require impossibly large heatsinks. It's an excellent way
of improving efficiency.

Graham


netkkkkopin ggarbage

It is? Why? All engineering is a compromise. Engineers are always
constrained by cost, size, performance, reliability, complexity,
esthetics, marketing B.S. When cost is no object, as is often the case
for high-end hi-fi enthusiasts, that removes a huge constraint.


Good grief.


Pooh bear is netkkkopin ggarbage.






Bertie

[Arny Krueger]

"Bertie the Bunyip" wrote in message
.130
"Karl Uppiano" wrote in
news:NVxYg.706$AR6.264@trndny02:

**Like I said, It has been done before, with variable
success rates. In reality, however, the BEST
amplification is still high bias Class A/B, with no
dodgy power supply rail switching schemes. Such
schemes are really only ways to cut costs.

The idea that class G is only a way to cut costs is false. At low power
levels it costs more to build a class G amplifier than a class A/B amp. You
can see this in the product lines of say QSC, who are one of the industry
leaders when it comes to designing, producing and selling class G
amplifiers. Their low-end models are class A/B. Power levels have to rise to
a certain level before the added parts and complexity required for Class G
starts paying off. I suspect that QSC even tips the scales towards class G
before pure economics cut in, because of the convenience factors.

It's done to cut down dissipation primarily.

Totally agreed.

In high power amplifiers this eventually become a very
significant issue and might otherwise require
impossibly large heatsinks.

When people step up to the problems of building mulit-killowatt amplifiers,
the space, weight, and size savings provided by class G become very
important.

It's an excellent way of improving efficiency.

It is?

For sure.

Why?

In a word, efficiency. The efficiency of a pure class A/B amplifier over a
range of typical use isn't all that wonderful. Numbers like 40% come to
mind. Class A/B amplifiers are generally most efficient near full output.
Class G essentially provides multiple "full output" operating points (one
for each power supply voltage) as power rises.

All engineering is a compromise. Engineers
are always constrained by cost, size, performance,
reliability, complexity, esthetics, marketing B.S.

Right on, and add convenience and general practicality.

When
cost is no object, as is often the case for high-end
hi-fi enthusiasts, that removes a huge constraint.

Hi Fi enthusiasts don't have infinite resources. There are issues like WAF
and simple practicality - a pure class A/B near-killowatt power amp can be
hard to ship except by truck, and difficult to simply get out of the box and
put on the shelf or in a rack.

[Bertie the Bunyip]

"Bret Ludwig" wrote in
oups.com:


Bertie the Bunyip wrote:





Aww. looks like I'm upsetting someone!




Far be it from me..


Bertie

[Bertie the Bunyip]

"Bret Ludwig" wrote in
oups.com:


Arny Krueger wrote:

snip

In a word, efficiency. The efficiency of a pure class A/B amplifier
over a range of typical use isn't all that wonderful. Numbers like
40% come to mind. Class A/B amplifiers are generally most efficient
near full output. Class G essentially provides multiple "full output"
operating points (one for each power supply voltage) as power rises.

All engineering is a compromise. Engineers
are always constrained by cost, size, performance,
reliability, complexity, esthetics, marketing B.S.

Right on, and add convenience and general practicality.

The problem is that high end buyers are willing to pay huge sums and
the manufacturers are willing to shave build cost and take colossal
profit margins rather than to put the full share of outlandish price
into the product.


When
cost is no object, as is often the case for high-end
hi-fi enthusiasts, that removes a huge constraint.

Hi Fi enthusiasts don't have infinite resources. There are issues
like WAF and simple practicality - a pure class A/B near-killowatt
power amp can be hard to ship except by truck, and difficult to
simply get out of the box and put on the shelf or in a rack.

Generally if you can afford such an amp you can afford the truck
freight and a rigging crew to mount the beast if necessary.


Sez you..

Bertie

[Arny Krueger]

"Stuart Krivis" wrote in message

On 16 Oct 2006 16:45:28 -0700, "Bret Ludwig"
wrote:


Arny Krueger wrote:

snip

In a word, efficiency. The efficiency of a pure class
A/B amplifier over a range of typical use isn't all
that wonderful. Numbers like 40% come to mind. Class
A/B amplifiers are generally most efficient near full
output. Class G essentially provides multiple "full
output" operating points (one for each power supply
voltage) as power rises.

All engineering is a compromise. Engineers
are always constrained by cost, size, performance,
reliability, complexity, esthetics, marketing B.S.

Right on, and add convenience and general practicality.

The problem is that high end buyers are willing to pay
huge sums and the manufacturers are willing to shave
build cost and take colossal profit margins rather than
to put the full share of outlandish price into the
product.

It seems that most of the cost of many boutique amps is
in the case and not the actual circuitry.

Not even that - its the marketing.

From a recent Mastercard ad: "Good review from Stereophile - priceless" ;-)

[Powell]

"Arny Krueger" wrote

Stuart Krivis wrote:

It seems that most of the cost of many boutique amps is
in the case and not the actual circuitry.

Not even that - its the marketing.

Note: One Broke-A$$® said to another.