How to Use a Power Amp & a Guitar Amp

The equipment used to amplify the signal of an electrical guitar to a usable performance volume consists of three basic stages. The preamp is used to adjust the tone of the guitar. This is the stage that virtually always contains the equalizer and overdrive features of the amp. The power amp stage amplifies the signal from the preamp to a stronger signal. The speaker cabinet turns the signal from the power amp into actual audible sound. Most guitar amps combine these components into one or two units. Rack amps are the only version that actually uses a separate power amp with the guitar preamp.

Things You'll Need

• Rack case
• Mounting screws
• Screwdriver
• Preamp
• Power amp
• Speaker cabinet
• Electric guitar
• 3 instrument cables

Instructions

1. Mount the preamp and power amp units into the rack case. Line up the holes on the two side wings of both units with the holes in the wall of the rack case. Screw mounting screws into place to hold the guitar amp components in place.

2. Connect an instrument cable to the output port of the preamp and the input port of the power amp. Both ports should be on the back of both units.

3. Connect an instrument cable from the output port of the power amp to the port on the speaker cabinet.

4. Connect an instrument cable from the input port of the preamp to the jack port on the electric guitar. The guitar amp is completely connected at this point.

5. Plug the preamp and power amp into electrical sockets. Both units will need to be plugged in to function.

6. Turn on the preamp and power amp. The rack guitar amp is now ready for use.

Tips & Warnings

• Most guitar amps are specifically designed to work with an electrical guitar. This leads to there being little to no interchangeability between guitar amps and parts and other instruments. The power amp is an exception because it is only designed to strengthen the signal it receives to output to speakers. You can use power amps designed for other instruments with decent results.

• Check the power rating for the speaker cabinet before connecting it to a power amp. The guitar amp can potentially ruin the speakers if the signal it sends is more powerful than what the speakers are designed to handle.

• Guitar amp heads contain a power amp. Do not connect these to a separate power amp unless it is specifically designed for that. The normal signal an amp head sends is too powerful for a standard power amp to receive.

References

• Rock Guitar for Dummies; Jon Chappell; 2001