"Phil Allison"

http://www.geocities.com/quad_esl63/...c/power303.jpg

** The output triples inherently limit at 4.5 amps.


** Silicon diodes MR105 & MR106 (along with TR7, the 1.4 volt Vbe
multiplier used for bias setting ) are responsible for this - in
combination, they limit the drive voltage at the input to each triple to
about +/- 2.1 volts, relative to the output line.

MR106 affects the upper triple while MR 105 the lower triple.

The Vbes of TR103 and TR104 plus voltage drops across R120 and R121 &
R124 and R125 add to +/- 2.1 volts when the current flowing into a load is
+/- 4.5 amps, respectively. Current limiting is not sensitive to the phase
angle of the load impedance.

Under shorted or very low impedance load conditions, the power dissipation
in each output device limited to 70 watts, worst case.



........ Phil

In article ,
Phil Allison wrote:
The interest in the Sugden amps mystifies me because they seem to be
so backward.


** A quirky, pommy amp only a quirky pommy could love.

I'd suggest you actually listen to one - especially into a pair of ELS 57s.
It sounds a deal cleaner than a 303 - although obviously slightly down on
power.

--
*Never put off until tomorrow what you can avoid altogether *

Dave Plowman London SW
To e-mail, change noise into sound.