2 pre-amps into one power amp?

I have been thinking about ways to use my stereo power amp with the output from both my AV processor and my stereo pre-amp.

Is there a good reason why I could not simply connect both outputs to the (single) input of the power amp using some sort of "Y" type splitter (obviously I would not use both at the same time)?

I am thinking here particularly of impedance issues as I know it is a very bad idea to connect two power amps to the same set of speaker terminals.

 

Yes it is a bad idea. You could damage the output stage on one or both pre amps by driving into an output.

 

Maplins will flog ya a switch so ya can switch between one or the other, bout £12

 

I was afraid that that would be the case.

I was worried that these would do something dire to the sound but at £12 I guess it's worth a punt - thanks

 

The common solution employed by many people is to route the pre-amp output of the AV amp through an unused input of the pre-amp. You then just need to adjust the AV channel output levels with the pre-amp volume set to some easily repeatable position; say 12 o'clock. This sort of approach removes the need for a switch, and should I believe work resonably well assuming your stereo pre-amp is significantly better than the AV one (which is usually the case).

 

Good thinkin, that would work well

 

I use such a switch and find that it is not at all detrimental.

 

This would work, I'm sure but sadly it's not an option for me.

Maplin switch ordered and awaiting delivery.

 

Brilliant idea.