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Running two amplifiers with one pair of speakers

V

vesuvian

pfm Member
Is it OK to connect 2 amplifiers to the same speakers (one with spade-terminated cables, the other with banana-terminated cables) and have only 1 switched on at any one time?

I don't really want to have to keep disconnecting and reconnecting speaker cables when switching between the 2 amps.
 
I have no expertise on this issue... But it sounds like a bad idea. The 'off' amp and the 'on' amp could be damaged. I don't expect the speakers will care unless you accidentally switch both amps on.
 
I don't think your scenario is that common.

Even if it is harmless (and I don't know if it is), it'll be an accident just waiting to happen should you turn on both amps.

I have multiple amps too, and two separate runs of cables. But I plug/unplug them at the loudspeaker end, so that only one amplifier is connected to the loudspeakers at any one time.
 
I have two amps.

Changing the speaker cables from one amp to the other takes me less than 10 seconds, using banana plugs on the cables.

I've never thought about any other solution as it seems simple enough to me.
 
Yep, accident waiting to happen. If you don’t want to change speaker cables from one amp to another some sort of switch is required. If one of the amps is a valve amp there needs to be a dummy load in case that amp is left on when not connected to a speaker. I looked at the Beresford switcher, but at the time it didn’t have a dummy load.
 
camverton said:
If one of the amps is a valve amp there needs to be a dummy load in case that amp is left on when not connected to a speaker.
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I didn't know that but I have a vague memory of asking the late T. de P. if I needed to have speakers plugged into my 509 mono's when they're on and think he replied that it wasn't essential, Could be wrong here.

I'm not sure why anybody would want two (power?) amps feeding one set of speakers except as in bi-amping but I guess sth has eluded me here.
 
I used to use a valve amp for music and a solid state for AV. Power consumption and cost of valves would have been a bit of waste for AV.
 
camverton said:
I used to use a valve amp for music and a solid state for AV.
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When I had a Na 250 back in the eighties I used to frequently unplug the speakers from the amp and plug in another set feeding speakers in the next room whilst the amp was on. No prob., but I wonder what it is about valved amps, either generally or just some push-pull types, to not like the absence of a load whilst being on.
 
As far as I can see, you are not going to run into immediate problems having a push-pull valve amp firing into no load if there is no, or even just a modest, signal input. I have a valve and a solid state amp going into my Beresford switch, but have not encountered any issues on the handful of occasions that the switch has been in the wrong position if it has taken me ten or fifteen seconds after switch-on to notice.
 
I have two amps connected to my speakers - A class A amplifier for sq and an AV amp for family. I use a Beresford TC7210 switch to switch between them, I can’t detect any degregation and this one also has a dummy load for the amp which requires a load.
 
vesuvian said:
Is it OK to connect 2 amplifiers to the same speakers (one with spade-terminated cables, the other with banana-terminated cables) and have only 1 switched on at any one time?

I don't really want to have to keep disconnecting and reconnecting speaker cables when switching between the 2 amps.
Click to expand...

Do you need the two amps?
 
Don’t do it, you will damage one or both amps. The way around it, as suggested above, is to use a switcher.
 
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