wrote:
I have an 80 wpc amp and am thinking of replacing my speakers.

With an 80W amp you don't have to worry. Buy speakers that you can live
with over the long term and your amp will no doubt drive them well.

In general, it is putting the cart before the horse to choose your amp
first and your speakers afterwards. Even in valves, where that happens
so often that the thoughtless can come to believe that choosing the amp
first is the correct procedure, it is counterproductive.

A couple of articles on my KISS netsite
http://members.lycos.co.uk/fiultra/KISS%20100.htm
KISS 102 by Andre Jute: The myth of the watt
KISS 103 by Andre Jute: Calculating the power our amp requires to drive
the chosen speakers
explain how little power you really require to drive even insensitive
speakers.

I had read that sensitivity is often compromised in higher end speakers
because higher end amps are often high wpc so can still drive them.

Too many speaker designers are slack incompetents who expect amp
designers to make up for their laziness and thoughtlessness; they run
after the pack and year after year turn out lowest common denominators
speakers.

Any overage is supposedly for transient spikes, an argument that
shortly leads to 2kW amps. I've had a couple of kW in amplification
power (12x 200W units where each pair bridged for 400W) for an outdoors
rock'n'roll poolside setup (it was built for me in 1969 by a couple of
chums from HP whose next invention was a heated brick in a fur wrap to
keep the feet of their departmental secretary warm) and we had to keep
a lock on the volume control and bribe the police and pay off the
neighbours within a three mile radius, and even then dogs and cats and
snakes went crazy and bit us, not to mention that the sound ****ed off
the piranhas I kept in my pool.

Although this sounds plausable I've also read that valve amps are ofter
low wpc. Besides dont amps prefer less work so they have more power in
reserve for fast transients?

I have valve amps from about a third of a watt to over eighty watts in
SE, and to over a hundred watt in PP. My squalid state amps run from
about ten watt to whatever a Quad 405 Mk II puts out (could be140W --
I've forgotten because it is an irrelevant number of importance only to
the marketing department). Besides the Quad which is permanently on and
might be switched in at any time, it is very rare for me to use an amp
of more than 20-25W, for the simple reason that that is enough to drive
anything to more than reasonable volumes. My everyday speakers are Quad
ESL-63 which are perhaps optimistically claimed to be 86dB/m sensitive.
That is, they are not very sensitive when compared to my Fidelio type
Lowther-driven horns at around 100dB/2m (only those who don't have
brains to put in gear measure a horn bigger than a tweeter at 1m)
in-box and 3dB better at least in-room. I drive the horns with an amp
of one third of a watt and shake the house with the bass by putting
them in the door of the top floor to use a four-story winding stairwell
as a horn-expansion and rooms on the way down as additional Helmholz
chambers; the treble goes up to 22kHz. You can see the horns and the
amp (a huge grey thing numbered Type 68 bis standing on its short end)
on my netsite via the URL under my sig. You can also see on the site
plans for very sensitive speakers (Impresario) I have designed for you
to build cheaply if you want to experiment with the sweetness of tone
available only in very low-powered valve amps. There are also some
cheaper ultrafi amps like the SEntry I designed for student use and
space.

Valve amps are in general more powerful than their bare ratings might
suggest. The ultrafidelista single-ended types (and quite a few PP
types as well if designed and built by the right people) operate in
Class A with maximum power permanently loaded and locked and ready to
rock'n'roll because they constantly draw a standing current even at
zero signal equal to maximum power, unlike your average solid state amp
which operates in class A/B if you're lucky, and doesn't come into real
power until it is well into Class B, that is, a Class B amp draws
current only when it is operating and then only proportional to output.
Compare the pressure in a water tank that starts full and (if correctly
choked and capped in the analogous power supply) stays at least
two-thirds full with one that starts empty and is replenished only to
the level of water drawn off (I could even argue that it is replenished
only to half the level of water drawn off, but that will just lead to a
nastiness with people who learned their engineering by rule of thumb
and have learned nothing since). The upshot is that in a valve/SS
comparison more is usually hidden than is illuminated. Valve/SS
comparisons are intrinsically unfair to SS even before you switch the
amplifiers on, and on switch-on become irremediably unfair unless cost
is an issue, which at our end of the audiophile spectrum it never is.
The same applies to comparisons of point source speakers, especially
dipoles to multi-driver boxes: the point sources and dipoles have an
intrinsic advantage in sonic quality over the multi-driver boxes, and
that advantage is multiplied when the multidriver box requires active
circuitry to do anything right.

Less is always more in the reproduction of music.

Just my opinion, of course. The majority has a perfect democratic right
to be wrong.

Duck!

Andre Jute
Visit Jute on Amps at http://members.lycos.co.uk/fiultra/
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