The most dramatic change I ever heard was in a shop when the removed the
Isobariks and tried Quad 63's. From awful to excellent. They shop droids
hated the Quads. But then they were unable to hear that one of the tweeters
in one of the Isobariks was busted... :-)


"Never in the field of domestic audio was so much bull**** dispensed by
so few and believed by so many"

With apologies to Winnie...
--
Tony Sayer

"Dave xxxx" wrote in message
k
On another forum a chap says, he has been told, its ok to
use a Quad power amp (140 watts) with a Quad 405 (100
watts) with the same pre amplifier.

The idea being the 606 powers the bass and the 405 the
tweeters.

This story comes around every once in a while - different details, same
basic old wife's tale.

Speakers being used Spendor s5e

Will this work ?

Yes, but without some engineering, it is pretty pointless.

Said Quad told him they have the same "gain"

Not true.

http://www.hifiengine.com/download_c...p?quad_606.pdf says the
606 puts out 140 watts with 0.5 volt input.

http://www.hifiengine.com/download_c...5_brochure.pdf
says the 405 puts out 100 watts with 0.5 volt input.

http://stereophile.com/floorloudspea...or/index4.html

Shows a fairly typical impedance curve. Note that the impedance of this
speaker in the tweeter's range is 10 ohms, which means that it is
providing only a small fraction of the total load on the power amp that is
driving it.

"Dave xxxx"

On another forum a chap says, he has been told, its ok to use a Quad power
amp (140 watts) with a Quad 405 (100 watts) with the same pre amplifier.

Said Quad told him they have the same "gain"



** Quad is a company, not a person.

What some staffer allegedly said on the phone to some fool who was incapable
of comprehending his own question, let alone the reply he got, is purest
******** !!


The 405 and the 606 have the same nominal " input sensitivity" of 500mV.

But NOT the same gain !!

The 606 has just on 2 dB more gain.



........ Phil