On Thu, 26 Jun 2014 20:17:43 +1000, Phil Allison wrote:
"Patrick Turner"
A short note to all:-
I was not completely happy with my old page on re-forming Quad-II amps
for improved performance.
** Nor was anyone else .
So I have now re-edited all schematics and removed much BS and added
more possibly useful stuff over the last month.
http://www.turneraudio.com.au/quad2powerampmods.htm
** The notion that the dual EF86 stage has less THD than the output
stage need correcting.
It does not, it has far more - about 5 times in fact - do our own test,
with the EF86s removed .
The correct result is in the vicinity of 0.2% THD at 10 watts and 1kHz
rising to 0.6% at 15 watts.
I consider myself well pre-battered by Quad-II zealotistas
** The Turneroid is like that mythical duck that all water runs off.
For "water" read rational thinking and fair criticism.
Quack, quack.....
As a matter of interest, Phil, have you tried the circuit that Keith Snook
has on his web page, where he uses cascode ECC88s instead of EF86s? It's
still basically the same circuit as Quads, but with triodes.
.... Phil