Dual Amp setup, switching between 5.2 and 2.0 (high/low power) speaker wiring


Standard Member
Hi, I have a Marantz SR6011 + Rotel RB-870BX setup that uses about 400W when they only are turned on being idle.

Now in the summer I don't need an extra heater in the room and so when I am not specially listing to good music or watching a movie, I wane use a low power class D amp (SMSL SA-98E), to watch TV in 2.0, also the power savings is also a nice extra benefit.

Next to that, if I switch over to 2.0 the surround from the Marantz and subwoofers connected to the Rotel will be turned off, and reduces the noise level true the rest of the house, making my wife and kids (hmm.. Mainly wife) happier. :rolleyes:

My question is how to switch between amps connected to the two main speakers?
I don't think I could have both amps connected to the same speakers, could I?
So I think I should use a relay to switch between amps, are there any relay boxes that could do that on the market, or do I have to make something my self, and what type of relay do I need then?

I have a 12 V DC/150 mA trigger on the Marantz, that I now use to switch on/off the Rotel, I could also use that trigger to switch an extra relay.

Anyone any thoughts on my plan


It looks like you need a stereo amp that has HT by-pass and not an outright power amp. A stereo amp with HT by-pass works as a power amp when connected by pre-outs, as you have done, with the Marantz. Any stereo source for music will just be connected to the HT by-pass stereo amp. When you listen to music then only the stereo amp is fired up.

Will work in exactly the same way as a power amp when you watch TV or discs with both amps needing to be fired up and the Marantz controlling the volume.

You will, according to your needs, want a stereo amp that has a trigger and also have a DAC onboard so that you can connect the TV to it by optical cable.

Here is a list of amps with HT by-pass.



Standard Member
My Marantz SR6011 has an HT by-pass, I used to connect the main canals to the Rotel RB-870BX driving two Vifa Basis loudspeakers that only sounded right with the very high dampening factor of the Rotel.

But I switched to a more reasonable size Polk Audio Signature S60e that got a better WAF rating, and with more stealth subwoofers.

What I want is to switch between my high power/high fidelity 5.2.4 setup that I only need 4~5 hours a week, and a 2.0 setup that is good enough to watch TV and series and listen to music more or less in the background.

This is my setup, and how I want to modify it

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