On Jan 23, 8:54*am, "David Looser"
wrote:
"Andre Jute" wrote in message

...



Mmm. I too have a 405 which has given sterling service. If it is so
efficient, I wonder why Peter Walker, not notably a waster, included
that large, expensive heatsink at the back.

I've no idea, perhaps it looks nice. Even when used as part of a stage PA
rig for an amateur musical (driving Bose SR speakers) it barely got warm to
the touch.

But you're the one who told us how efficient the 405 is, David. Now we
discover you believe that the heatsink is superfluous. Those are
mutually inconsistent statements

I have a PSE 300B amp that cost about 1600 Euro to build, about the
price of a modern equivalent of the Quad 405 MkII. It's lasted fifteen
years.

And how many new valves has it needed in that time?

Why, none. I must say, David, I'm surprised that you should, on no
evidence whatsoever, assume that I treat my equipment as roughly as
you apparently do yours.

It consumes about 120W for stereo. That's *less* draw at full
power than the Quad 405 MkII.

And for just how much of the time is a domestic HiFi amp used at anything
even remotely near full power? The 405 and 44 pre-amp together consumes 35W
most of the time, occasionally flicking up to around 50W or so on the
loudest passages whilst driving my Tannoys.

smaller SE 300B amp consumes about 50W
for stereo and just idles along with horns but the 405 must draw down
more than the SE amp to drive ESL-63 to the same SPL as the 300B
drives the horns.

Ah! you give different goal-posts to the two I see. A 405 must drive
ESL-63s, whilst the SET amp can be allowed horns. That's a comparison
between ESLs and horns, not between SETs and the 405.

But the amazing thing here isn't your carelessness with the numbers

I think I've pointed out that it's you who are being careless with numbers..

but the hubris of telling me how your flavour of an obscenely
expensive hobby is saving he planet!

Hey! you started it with your inane suggestion that SET amps somehow or
other fit the "small is beautiful" philosophy.

Here you go again lumping all SET amps into one basket, and pouring a
liberal helping of ignorant prejudice over the basket.

If you want a SET that fits the "small is beautiful" philosophy, just
cruise my netsite or ask me. Here
http://members.lycos.co.uk/fiultra/t...17acircuit.jpg
http://members.lycos.co.uk/fiultra/K...0T68MZ417A.jpg
for instance, you will find my T68 "Minus Zero", a one-third watt SET
amp which, for less draw from the wall than many battery amps, drives
Lowther Horns to ecstasy.

You anti-SET fanatics are even less rational and consistent than the
audiophools who think a SET is the be-all and end-all of quality
sound. Neither is interested in listening to reason, or capable of
understanding that all such choices are subject to qualification.

Andre Jute
Visit Jute on Amps at http://members.lycos.co.uk/fiultra/
"wonderfully well written and reasoned information
for the tube audio constructor"
John Broskie TubeCAD & GlassWare
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containing vital gems of wisdom"
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David.