2. amps-preamps
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Disconnecting speaker while power amp on - any dan


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!!!
zormi
atmasphere's avatar
atmasphere
11,944 posts
 
Zormi, The load becomes infinite when the speakers are not hooked up. Its OK as long as there is no input signal to the amp. If there *is* an input signal, some amplifiers can be damaged, both tube and solid state.

So if you disconnect the speaker, just make sure that the input signal is turned all the way down.
mmakshak
589 posts
 
I believe that I blew a Classe amp when a speaker cable became disconnected from it.
atmasphere's avatar
atmasphere
11,944 posts
 
Yes, if you have signal applied all bets are off!
zormi OP
105 posts
 

Thanx guys,

Things pretty calm now... Amp OK, nerves as well.
unclejeff
1,313 posts
 
Yes, truly bananas are better than spades.
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