Is this dangerous ?

You can try it and see what happens. I would certainly never do that. And I'm assuming you have jumpers between the 2 sets of speaker jacks.

Wouldn't the signal feedback through the second set of cables?

Hopefully, one of the electronic techs will weigh in here. But until one does -- I advise don't do it.

As Meiwan surmises, I too suspect that if both amps are tied in simulataneously, the outputs will short unless the amp not in use is disconnected from the circuit.

Perhaps a call to the factory would be worthwhile.

Is this dangerous ?

Yes, it absolutely is dangerous, mainly to the amplifiers. The outputs of two power amplifiers (or the power amplifier section of a receiver or integrated amplifier) should never be connected together. See this thread for further explanation, and for suggested solutions.

Regards,
-- Al

Get a 2-channel preamp with a home theater bypass circuit. Then follow the instructions on connecting it all together.

Or, if your HT receiver has preamp outputs, connect the Left and Right front channel pre-outs from the receiver to a pair of line level inputs on your amp (or preamp--you're not very detailed on what your setup is).

If your AV receiver doesn't have pre-outs, sell//trade it to get one that does. The ones that do aren't that expensive.

My plans are to get a pair of tube amps for 2 channel which i do not want running day and night . I can either unplug the receiver when not in use or swap the speaker cables each time. Lots of wear on the bannanas that way though . Unplugging the receiver is probably the best and safest way . I do not want to invest in expensive items to remedy this issue. ie: new bypass preamp.

Unplugging the receiver is probably the best and safest way.

No it is not. As discussed in the link I provided earlier, when running one amp with the other unplugged you would be applying the full output voltage of the amp that is being used to the outputs of the powered down amp, with unpredictable and design-dependent consequences that could quite possibly include sonic degradation and/or amplifier damage.

Consider purchasing one of the switching devices that were mentioned in the other thread.

Regards,
-- Al

06-10-12: Maplegrovemusic
... I do not want to invest in expensive items to remedy this issue. ie: new bypass preamp.

The Parasound Classic 2100 has everything you need (and then some) for $649, which is no doubt cheaper than the expense you'll have if you make a mistake ONE TIME in switching between the two amps, in which case you may have to fix/replace your AVR, power amp, and speakers. Plus, the Parasound is a very good unit and very versatile. It has a built-in phono preamp *and* bass management with selectable crossover frequencies if you want to run a subwoofer.

One time when I was a newbie working in a stereo store, I made such a switch and even though I'd turned off the first amp, the two amps STILL blew out each other's output stages because the amp is still putting out current for a few seconds after you turn it off--even if you unplug it. It's the capacitors discharging.

It seems to be a reasonable expense for the amount of safe flexibility it would bring to your rig.

Listen to Al!!!!

06-10-12: Bifwynne
Listen to Al!!!!

And to Johnny also, of course.

Thanks very much, Bruce (Bifwynne).

Best regards,
-- Al

I integrated my 2-ch system into my home theater, without a theater bypass option on my preamp. While this feature is useful, it is not required. I simply run the left/right main outputs of my AVR (obviously, this requires line-outs for at least the main left/right channels, your system link does not list which surround receiver you have) into an input on my stereo preamp. The stereo preamp feeds an amplifier for the front main speakers, while the AVR powers the rest of the speakers in the system. Having full range speakers up front is preferable in this setup scheme. Setting the stereo preamp to a repeatable volume setting (I have a digital readout, so I use "60") I then balance the surround channels. Any time I want to listen to a surround source, I just set the stereo preamp to "60", and use the AVR's volume control to adjust the volume for the whole system. When I want to listen in stereo, I just select a different input on the stereo preamp, and shut down all the surround gear. For video, I run HDMI from my universal player into the AVR, and the digital stereo output to a DAC, which in turn feeds an input on the stereo preamp. No need to hook up multiple amps to my speakers, which is indeed dangerous. BTW, the second set of binding posts are not for hooking up a second amp with a different signal, they are for bi-amping or bi-wiring the speakers, which is something completely different.