If you want to gain more control over the sound of your guitar amplifier, or want to imitate a specific tonal character that your amp just can't create, then an external preamp can be a great addition to your rig.
Guitar Preamps
Most modern guitar amplifiers have both a preamp and a power amp built in. The power amp is the final stage, and prepares the amplified signal before it can be sent to the built in speaker of a combo amplifier, or an external guitar speaker cabinet. The preamp is the first stage, so it's responsible for the core sound or tonal character of your amplifier. Both stages are essential, but when you take two amplifiers that have the same power amp section but a different preamp section, the difference in sound can be massive. Most of the time, the preamp and power amp sections are integrated into the same design, but you can also pick up external preamps and power amps. You can even get preamp pedals that are able to alter the sound of your amp, and some models are even specially designed to mimic the character of an iconic guitar amplifier.
Guitar DI Boxes
Some preamps also feature a built-in DI box so they can be directly hooked up to a mixer or sound system but with all the benefits of the meaty sound of an amplifier. Some preamp-plus-DI models also add a speaker cabinet simulation to the output, so you're assured of proper, authentic guitar sound despite the stripped-back setup. In any case, a DI box can be a useful tool for gigging guitarists, since it prepares your output signal for the mixer by converting it from an unbalanced high-impedance signal into a balanced, low-impedance signal. Basically, it removes the need to set a microphone up in front of the amp. See our full range of DI boxes.
Guitars with Built-In Preamps
There are also guitars that come with a preamp built-in. Commonly, these are electro-acoustic guitars and will often have a preamp control panel fitted on the side, usually with a set of pots for adjusting the treble, mids and bass. You'll find this kind of preamp in our Guitar Parts department.
Frequently Asked Questions About Guitar Preamps
Is a guitar preamp an effect pedal?
A lot of external preamps come in a pedal housing to make it easier for guitarists to radically switch up the sound of their amplifier quickly and easily. Of course, you can also get external rack preamps which can be less convenient, depending on your setup.
Do I need a guitar preamp?
To get any sound out of your speaker cabinet, you'll always need a preamp, and luckily, one will come built into most guitar amplifiers already. But if you want to be able to dramatically change up the sound of your amp and gain deeper control over it, then you might think about getting an external preamp.
