Keith G wrote:
wrote in message
ups.com...

Nick Gorham wrote:

Jim Lesurf wrote:

In article , Nick Gorham
wrote:


Rob wrote:


It strikes me that the valve amp is the problem here - SS amps don't
need a dummy load. Really, your suggestion is fine. I'm just trying to
factor in certain extreme scenarios - say, someone else using the
stereo.




Don't bother if the amp has triodes on the output, its only Pentodes
that will get upset with no load.


Can you explain why? Afraid I don't know why an amp built with triodes
would be inherently incapable of becoming unstable when unloaded.


No reason why it shouldn't become unstable, but the fact remains that a
triode is happy with a choke load, which the transformer (ignoring
OTL's) will become when unloaded. The pentode will not however like that
load and you can end up with high dv/dt that could cause problems in the
output TX.


Phew! Sorry Nick/Jim, didn't get much of that. Do you think this amp:

http://www.beardaudio.com/p100-505broc.pdf

(the power amp only, obviously) would be safe switched on and not
connected to speakers?


No, I would not trust that without a load, I would guess its a pentode
or UL output stage.

--
Nick