Connect the 2 Channels of a Power Amp Together?

mfbf

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Mar 8, 2002
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I have the following 2-channel power amp to drive some speakers throughout my house. My receiver's line out is driving the power amp and the power amp drives a speaker selector/volume switch.

Each channel is 50 W on the power amp but can I connect Speaker A and Speaker B together to get 100 W output?

Thanks for any input.
 

Rubycon

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Aug 10, 2005
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In theory you can. It's called bridging and how it works is you are connecting both channels in series just like a battery. For it to work the left and right inputs MUST be 180 degrees out of phase. Some crossovers have a bridging function and that is exactly what this does.

It's always best to contact the equipment manufacturer to make sure this will work however most will probably brush it off with a resounding NO. Compatibility can be tested at low (signal) levels and if there is a problem the protection circuit will engage before any damage is done. Heck if you're measuring millivolt gains the protection circuitry won't even interact!
 

CallMeJoe

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Jul 30, 2004
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Originally posted by: Rubycon
In theory you can. It's called bridging and how it works is you are connecting both channels in series just like a battery. For it to work the left and right inputs MUST be 180 degrees out of phase. Some crossovers have a bridging function and that is exactly what this does.
It's always best to contact the equipment manufacturer to make sure this will work however most will probably brush it off with a resounding NO. Compatibility can be tested at low (signal) levels and if there is a problem the protection circuit will engage before any damage is done. Heck if you're measuring millivolt gains the protection circuitry won't even interact!
If you click his link, you will find it is listed as a bridgeable amp...
 

Rubycon

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Aug 10, 2005
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Originally posted by: CallMeJoe

If you click his link, you will find it is listed as a bridgeable amp...

Sorry that site is not allowed here.
 

mfbf

Senior member
Mar 8, 2002
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Originally posted by: CallMeJoe
Yes, you can use this as a mono amp, but it will deliver 150W, not 100.

Read the manual here.

I knew that from the manual but I was hoping for stereo output of 100 W.
 

Rubycon

Madame President
Aug 10, 2005
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Originally posted by: mfbf
Originally posted by: CallMeJoe
Yes, you can use this as a mono amp, but it will deliver 150W, not 100.

Read the manual here.

I knew that from the manual but I was hoping for stereo output of 100 W.

:confused:

Bridging a stereo amp yields a mono amp at (usually) 6dB gain IF the power supply is well regulated and the speaker impedance is unchanged. For stereo you would need two amps in bridge mode. Remember bridging effectively halves the impedance seen by each channel so 4 ohms is usually the minimum for a bridged amp. (2 ohms per channel).