Jim Lesurf wrote:



** You mention speaking with Peter Walker about the "crow bar" circuit
in the ESL63. Here is a schem for an early version.

http://www.quadesl.com/schematics/quad63_schematic.gif

The triac used is a T6000B, rated at 16 amps continuous and 150 amp
surge for 10mS. Other units use a T2800B, rated at 8 amps with a 100 amp
surge rating.

Later ESL63s, from 1989 onwards, used a TIC216D, rated at 6 amps with a
50 amp surge rating.

http://www.euronet.nl/users/temagm/a...ematic_new.jpg

As the crow bar is intended to clip transients that exceed the voltage
limit of the panels and only to be used with amplifiers that have
electronic current limiting, any of the above are more than adequate.

Agreed. But the 732 *doesn't* have current limiters and can deliver
sustained RMS currents above the values you gave.


** The 5A rail fuses you fitted to the 732 would prevent that in most cases.

PLUS, Your article incorrectly said the triacs were 5 amp rated.



PJW clearly intended the ESL to be used with amps like the 405 which had
current limiters. But I felt they were a PITA for people who had
'difficult' speakers - as the orginal 405 design actually showed very
neatly.


** Quad modified the original 405's current limiter in response to ill informed criticism in some reviews - not because owners experienced a real problem.

Ironic that you new page so strongly bemoans the often unfair effects of erroneous reviews on amp makers.



..... Phil