The Cyber-Spy.Com Usenet Archive Feeds Directly
From The Open And Publicly Available Newsgroup
This Group And Thousands Of Others Are Available
On Most IS NNTP News Servers On Port 119.
Cyber-Spy.Com Is NOT Responsible For Any Topic,
Opinions Or Content Posted To This Or Any Other
Newsgroup. This Web Archive Of The Newsgroup And
Posts Are For Informational Purposes Only.
From: "Phil Allison"
References: <firstname.lastname@example.org> <email@example.com>
Subject: Re: 'Current Dumping' Amplifier Circuits ?
X-Newsreader: Microsoft Outlook Express 5.50.4522.1200
Date: Mon, 2 Dec 2002 23:11:28 +1100
NNTP-Posting-Date: Mon, 02 Dec 2002 23:00:40 EST
Organization: Telstra BigPond Internet Services (http://www.bigpond.com)
"Kevin Aylward" wrote in message
> Phil Allison wrote:
> > "Roger Lascelles" wrote in message
> > news:firstname.lastname@example.org...
> >> I think Wirless World (as it was then) ran an article which
> >> explained the idea. From memory, they showed a high power class B
> >> power stage with lots of crossover distortion and a lower powered
> >> class A (?) stage which added an additional contribution to the
> >> output to cancel out the distortion of the Class B. Idea is that a
> >> rugged output stage with no thermal runaway but mediocre linearity
> >> can work with a low power fast & clean amp.
> >> It may be unnecessary - other high quality audio amps do not use it.
> > ** Proves what ??
> It forms a good indication, for *whatever* reason, that any positives of
> the technique, are outweighed by the negatives.
** This comment conveys no information - except about the writer.
> In general, it appears that the use of the technique is simply not worth
> the "bother".
> > If I>> was building an amplifier, I would not bother.
> > ** A comment about yourself.
> And your point would be?
** It pretends to be about the subject - but is not.
> The poster asked for an opinion, Roger gave one.
** Yes, but not not about the subject but instead his own fuzzy
> > If I chose a Quad amp, it
> >> would be becuase it sounded good and was priced right - not because
> >> of current dumping.
> > ** It is a nice feature, that others lack.
> What's specifically nice about it for the *user*?
** The "nice" is not something an average user would be aware of.
> From a technical point of view, it removes the requirement to adjust a
> bias pot, but other then a potential very modest cost effect, is of no
> relevance to a user.
** Right - and the Crown DC 300 A is a crap amp. We have an expert
for sure here.
It also reduces the standing current in the output
> stage, but again, this current is merely moved to the class A driver
** I removes output bias current and all the associated bias stability
issues that affect THD at low levels. That is nice.
Go Back To The Cyber-Spy.Com
Usenet Web Archive Index Of
The sci.electronics.design Newsgroup