Do all amp speakers need to be connected when the amp in running?

[capn_gaz]

Hi guys just thought of something which got me thinking, I know it says in amp manuals you need to connect some speakers to the output because of some reason or another, like either the amp will explode or the world will end - but say with my BC30, if I connected it up at the back like normal but then unplugged just one of the speakers at the two wires - would this be fine? So in effect just using a single speaker rather than both - just wondering if this would be handy to turning the amp up just that bit more at home to keep the volume down and overdrive it a little more.

 

Didnt fancy trying it incase something catastrophic happened to the amp and the world around it.

 

Cheers,

 

Gareth

[Dave]

If you can unplug one of the speakers and still get sound, they are wired in a parallel for a 2 speaker cab or series parallel configuration for a 4 speaker cab. If you unplug one and all sound goes away, they are wired in series.

 

In any case, when you unplug a speaker, you change the impedance of the load to the amp. If two 16 ohm speakers were wired in parallel and you unplugged one, you would go from 8 to 16 ohms. The result would be a loss in power and your amp would probably be ok. You would have a mismatch to the output transformer 's output impedance and the tubes would work less efficiently.

 

If you want to experiment, get an ohm meter and monitor the load to the amp with the various combinations. Make sure that you know what the recommended impedance for the amp should be. Match this as closely as possible. DO THIS WITH THE POWER OFF SO THAT YOU DON'T GET SHOCKED OR BLOW A COMPONENT.

 

Remember that when you start experimenting, you run the risk of letting the smoke out of some components... BE CAREFUL and READ ABOUT OTHER's MISTAKES. Google it!

[capn_gaz]

If you can unplug one of the speakers and still get sound' date=' they are wired in a parallel for a 2 speaker cab or series parallel configuration for a 4 speaker cab. If you unplug one and all sound goes away, they are wired in series.

 

In any case, when you unplug a speaker, you change the impedance of the load to the amp. If two 16 ohm speakers were wired in parallel and you unplugged one, you would go from 8 to 16 ohms. The result would be a loss in power and your amp would probably be ok. You would have a mismatch to the output transformer 's output impedance and the tubes would work less efficiently.

 

If you want to experiment, get an ohm meter and monitor the load to the amp with the various combinations. Make sure that you know what the recommended impedance for the amp should be. Match this as closely as possible. DO THIS WITH THE POWER OFF SO THAT YOU DON'T GET SHOCKED OR BLOW A COMPONENT.

[/quote']

 

Thanks for the reply Dave, I was hoping your answer would simply be a simple "yeah, no problem" kind of deal - think I will just leave it if it needs that kind of careful experimentation!

 

Cheers,

 

Gareth

[jefrs]

The stock BC30 speakers are 16ohm each wired in parallel to 8ohms the pair. They are rated 70 watts.

 

If you unhook one of them you must connect it as 16ohm. It is do-able.

 

I have replaced mine with 8ohm each, switchable to either 16ohm or 4 ohm the pair, or individual (they're not the same). The 16ohm connection sounds better than the 4ohm. I did this because (a) they're better speakers, ( I can now add a conventional ext cab.