Reply-To: "Kevin Aylward"
From: "Kevin Aylward"
References: <email@example.com> <firstname.lastname@example.org>
Subject: Re: 'Current Dumping' Amplifier Circuits ?
X-Newsreader: Microsoft Outlook Express 6.00.2800.1106
Date: Mon, 2 Dec 2002 10:19:52 -0000
NNTP-Posting-Date: Mon, 02 Dec 2002 10:19:55 GMT
Phil Allison wrote:
> "Roger Lascelles" wrote in message
>> 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.
In general, it appears that the use of the technique is simply not worth
> If I
>> was building an amplifier, I would not bother.
> ** A comment about yourself.
And your point would be?
The poster asked for an opinion, Roger gave one.
> 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*?
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. It also reduces the standing current in the output
stage, but again, this current is merely moved to the class A driver
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