In article , James Perrett
wrote:


I remember Crown (or Amcron as they were known in the UK at that time)
demonstrating the robustness of one of their large amps at a hifi show
by connecting the speaker outputs to two parallel bars and putting a
screwdriver across the bars. This gave a shower of sparks whenever the
screwdriver was moved.

FWIW I more than once spent a day doing this with the amp I was designing.
The result wasn't only sparks. It meant I went though a boxes of rail
fuses[1], and had to replace the o/p binding posts as there were so many
burns and broken spot welds on the threads that I could no longer wind down
the spinners. The scrwdriver tended to look 'abused' as well... :-)

[1] The distinction being that I relied on dc line fuses for 'protection'.
Less convenient than current limiters, but allowed the amp not to be
bothered with current limiter effects. ;-)

The 'crown' test is easy enough for amps that have current limiters. The
real test is to determine what current or voltage the amp can actually
deliver without limiting.

Slainte,

Jim

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