Disconnecting speaker while power amp on - any danger?

[Zoran]

Something like this happened yesterday - managing to disconnect the left speaker (B&W 803S), I just missed to turn off the Rotel RB-1090. Nothing dramatic happened - there was not any “pop” sound from speaker, not the amp protection circuit was activated nor fuse burned... Probably because the preamp was turned off (or maybe on? - being upset at a moment I am not able to recall 100%..., but FOR SURE without any signal from the CD) Only my nerves suffered...

What is actually going on in such a situation, electronically speaking?

I can guess that the disconnected half (channel) of the amp “is seeing” a change in the level of resistance, unlike the other channel, still connected to the speaker. What a change is it? Is the disconnected channel “seeing” an ENDLESS resistance, or ZERO resistance?

IS THIS SITUATION HARMFULL FOR THE AMP CIRCUITS, even if no visible reaction of the amp (protection, fuses etc...)?

Electronic engeneers - any thoughts???

Thanx!!!


:cry:

[Aussie Geoff]

Disconnecting the Amp from the speaker while the Amp is live does nothign to the amp providing the two ends of the speaker wire aren't acidently touched together (even for a fraction of a second) - as this touching creates a short circuit which, depending on the model amp will generally blow the fuse or engage a protection circuit / light etc... That's why they always recommend turning the amp off first... That asside having the amp not drivng a speaker or just connected to a wire (ends separate) does it no harm.... (There are a few exotic amps that don't like no load - but they aren't current Rotels so lets ingore them)

Enjoy your system

Geoff

[Zoran]

Thanx Geoff. The amp works absolutely flawlessly after the "incident". But, this situation raised some theoretical stuff possibly interesting to be discussed overhere...

Could you explain, for instance, the mode of resistance change in the disconnected channel? Does the resistance go to ENDLESS or to ZERO?

Can anyone?

Thanx,

Zoran, Macedonia

[soundhound]

Infinate when open,
short the wires and it goes to zero.
Also I wouldn't recommend doing that with a pure class A amp whereas they are biased with no signal present.
Hot swapping is not good practice regardless.

[Nuthed]

My 16 month old pulled the bananas out of one speaker and shorted the leads. 2, 125volt, 5 amp fuses later and I was back in business.
So in short if it still works, I'd say its fine.

[soundhound]

Who hid the bananas in the speaker in the 1st place?

[Nuthed]

I needed a place for them because the apples were in the center.