How to Wire an External Amplifier


After reading our article “Do You Need an External Power Amp for Your AVR?,” you might be interested in how to integrate an external amp into your system. I’ll show you the basics of connecting the external amplifier to the speakers and the audio/video receiver (AVR) or processor.


The first step in adding new equipment to your home theater is to make sure that all of the equipment is turned off and unplugged before working on it. This is important to protect both yourself and the equipment from electrical damage.

Before wiring the new amplifier, make sure it is placed in its permanent location. Remember to provide sufficient airflow around the unit. If you are not sure about the space requirements, refer to the manual that comes with the amplifier. If you need further help on how to ensure that your amp is getting enough airflow, please check out our article called “How to Keep Your AV Equipment Cool: Passive and Active Cooling Methods.”

Another helpful tip is to label all of the wires, which will ensure that everything is wired correctly the first time. This includes labeling what channels will go into which locations on the new amp. For example, if you are moving the Left, Center, and Right channels to an external amp, you want to label each input on your amp to Left, Center, and Right.

Connecting Speakers to the Amplifier

Once everything is ready and the new amplifier is in place, the next step is to connect the speakers to the amplifier.

New System

If you are setting up your system for the first time, we have a helpful post called “How to Wire up Your Speakers!” that can guide you through the process of wiring.

To connect the speaker wires to the amp, start by removing the insulation at the ends of the wires to expose the copper strands. Then, insert the wires into the corresponding terminals on the back of your amplifier and your speakers. These terminals are usually either spring-loaded or screw-type, so you will need to push or twist them to secure the wires. It is important to ensure the polarity is correct, which means that the red wire should be connected to the red terminal, and the black wire should be connected to the black terminal on both ends.

If you are using banana plugs, make sure they are installed correctly and then insert them into the corresponding channel outputs on the amp.

Existing System

If you are adding the amplifier to your existing system, the existing speaker wires will need to be removed from their terminals in the AVR (audio/video receiver).

Once the speaker wires are removed, inspect them for any damage. If the wires are bare copper, twist the exposed copper strands together again before reconnecting them to the new amp. This will ensure a proper connection in the new amplifier. If banana plugs are being used, make sure the wires are securely attached to the banana plug before reconnecting.

Another important check is to ensure that there is enough wire length to reach from the speakers to the external amplifier, leaving some slack for adjustments. Straining the wires could negatively affect your audio quality. If there is not enough speaker wire then you may want to consider changing locations of the new amp to where the existing AVR is. If that is not an option, then you may want to re-run your speaker wire.

Connecting the AVR/Processor to the Amplifier

The next step is to connect the AVR or processor to the amplifier. There are two types of connections that need to be installed: the audio signal cables and the trigger cable.

Signal Cables

There are two types of audio cables that are usually used for transmitting the audio signal to the external amp, RCA cables or XLR cables. RCA cables have red and white plugs, while XLR cables have three-pin connectors. For a deeper dive into the differences between XLR and RCA cables, please check out our article, “Types of Audio Cables For Home Theater.”

Example of a wiring diagram to connect an external amp to the AVR.

Depending on the equipment, there might be different options for connecting the AVR or processor to the amplifier, so be sure to check the back of the device or owners manual for what connectors are used and ensure that the devices have the same connection types.

Connect the RCA or XLR cable to the corresponding pre-out channel on your AVR or processor. These jacks allow the signal to bypass the internal amplification of the AVR or processor and use only the external amplifier for power. Then connect the other end to the corresponding input on the external amp that has the correct speaker attached.

You will need as many RCA cables or XLR cables as you have channels you plan to amplify. For example, if you are adding 3 channels of external amplification, you will need 3 separate RCA cables.

Note: Some AVRs allow the internal amps to be turned off when using an external amp, be sure to check the owners manual to see if it has this feature. This is preferred because turning off the internal amp will decrease the amount of electrical noise in the system and help improve audio quality.

Editor's Note by Roland: Some AVRs have a pre-amp mode that allows you to turn off all the internal amplifiers, while newer AVRs will allow you to turn off individual channels. Check your owner's manual, as Tyler said, but make sure to note these two separate options on some newer AVRs. Unfortunately, if the AVR only has a pre-amp mode, then it is an all or nothing affair: you either turn off all internal amps or none. However, it isn't a huge issue to leave internal amps on, only if you are listening at higher volumes where clipping and noise could occur as the internal amps pollute the pre-amp signal.

Trigger Wire

The last step is to connect a trigger wire between the AVR or processor and the amplifier, if the AVR and amplifier support it. A trigger wire is a thin cable that sends a low-voltage signal from one device to another, telling it when to turn on or off automatically. This way, you don’t have to manually switch the amplifier on or off every time you use your system.

To connect a trigger wire, a 3.5mm mono cable (image above right) that has a single plug on each end is needed. Connect one end to the trigger-out jack of the AVR or processor, and the other end to the trigger-in jack of the amplifier. Make sure the trigger voltage matches between both devices, usually 12V or 5V.

If setting up multiple external amps, each one will require a trigger cable to enable automatic turn-on. One option is to check if the external amp has a trigger input and trigger output. This allows the connection of external amps in a daisy-chain configuration, so they all turn on and off along with your AVR. If that is not possible, a splitter for the trigger cables can be used to distribute them to as many amps as needed.


Once the new external amp is wired into the system, test your system to ensure that everything is working as intended. Remember to plug in all equipment that was unplugged during the installation process.

Once the system is tested to be working, the final step is to recalibrate the system. This is because when there is any change in the audio chain it can throw off the prior system calibration.

We offer extensive calibration guides depending on the room correction software you are using on your AVR. You can check them out below:

Alternatively, check out the corresponding free guides:

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