Stewart Pinkerton wrote:
On Mon, 1 Nov 2004 16:21:48 +0000, Glenn Booth
wrote:


Sorry to change the subject in mid thread, but how difficult a load are
the ESL63s? Any opinion on whether they would be happy on the end of an
Audiolab 8000S? Sadly, the 988s are beyond my budget, so second hand 63s
are on my shopping list.


That classic amp had excellent load tolerance, and isn't quite
powerful enough to trip the 'crowbar' in the ESL63, so it should be a
very good match.


'crowbar'? do you mean arcing?

Tat Chan wrote:
Stewart Pinkerton wrote:

On Mon, 1 Nov 2004 16:21:48 +0000, Glenn Booth
wrote:


Sorry to change the subject in mid thread, but how difficult a load
are the ESL63s? Any opinion on whether they would be happy on the end
of an Audiolab 8000S? Sadly, the 988s are beyond my budget, so second
hand 63s are on my shopping list.



That classic amp had excellent load tolerance, and isn't quite
powerful enough to trip the 'crowbar' in the ESL63, so it should be a
very good match.


'crowbar'? do you mean arcing?

No, the first quad els was prone to arcing if overdriven, so the 63 had
a crowbar protection circuit that protected the speaker, but upset
amplifiers that didn't like driving a short circuit.

--
Nick

Nick Gorham wrote:

Tat Chan wrote:

Stewart Pinkerton wrote:

On Mon, 1 Nov 2004 16:21:48 +0000, Glenn Booth
wrote:


Sorry to change the subject in mid thread, but how difficult a load
are the ESL63s? Any opinion on whether they would be happy on the
end of an Audiolab 8000S? Sadly, the 988s are beyond my budget, so
second hand 63s are on my shopping list.




That classic amp had excellent load tolerance, and isn't quite
powerful enough to trip the 'crowbar' in the ESL63, so it should be a
very good match.


'crowbar'? do you mean arcing?


No, the first quad els was prone to arcing if overdriven, so the 63 had
a crowbar protection circuit that protected the speaker, but upset
amplifiers that didn't like driving a short circuit.


Ah, thanks. So how would I know if an amp had short circuit protection?
I have the same Audiolab amp as Glenn.

In article , Nick Gorham
wrote:
Tat Chan wrote:


'crowbar'? do you mean arcing?

No, the first quad els was prone to arcing if overdriven, so the 63 had
a crowbar protection circuit that protected the speaker, but upset
amplifiers that didn't like driving a short circuit.

'Fortunately' sic they used to fit triacs that were 5-amp rated
(continuous). Hence if your amp is enthusiastic it can vaporise the triac,
then have a go at the speaker. 8-]

Never a problem with amps like the 405 as they used current limiters to
protect the triac as well as the speaker and the amplifier. :-)

However provided your apm never applies excessive volts, there should be no
problem. FWIW I cheerfully used the 63s with a 200W amp for 20 years with
no problems.

Slainte,

Jim

--
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