What’s a Preamp Pedal For?
The short answer is: yes.
Jokes aside, it can actually be somewhat confusing, but in this blog entry, I aim to break it down for you in a way that is easily understandable so that you can make the right choice when you decide that you desire a preamp pedal for your rig.
Before we discuss what a preamp pedal can and cannot do, we must first address the essence of a preamp. To best describe this, let’s use a combo amp or an amp head as an example. The circuits contained within these amps are made up of a great number of components, both large and small, the create the sound of the amp. The two arguably most important sections of these components are classified as a preamp and a power amp.
- The power amp section will generally contain, among other things, power tubes and transformers. The tube complement contained within the power section is usually the most cited spec in any given amp, i.e., this one has 6L6/EL34/EL84/KT66/KT88 tubes. A power amp tube complement will determine the wattage of an amp, and the type of power amp tube will generally have a distinct breakup characteristic when the amp is pushed into overdrive. For example, the overdrive of an AC-10/AC-15/AC-30 can be attributed to the construction of EL84 power tubes that causes them to break up early. Tubes used in Fender amps, generally 6V6 in lower wattage amps, and 6L6 in higher wattage amps, have a higher headroom and stay cleaner, louder, especially 6L6 tubes. This is why you can go very high on the volume dial of a Twin Reverb without it distorting.
- In its simplest terms, the preamp section can be described as the circuit that produces the tonal flavor of an amp and almost always includes the EQ which will allow you control over the treble, bass, mids, etc. Preamp sections can also contain tubes as well as many other components such as resistors, capacitors, etc. A preamp is as essential to an amp as air is to humans. You simply cannot amplify a guitar properly without a preamp somewhere in the circuit. Have you ever tried to plug your electric guitar direct into a recording interface at home to be left wondering why the playback sounds so completely muddy, dull, and lifeless? That’s because that’s how pickups sound without a preamp to provide the tone needed to amplify a signal that is listenable. This is why home recording enthusiasts will use a series of virtual preamps/amp models/virtual cabs and impulse response models to make direct guitar recording sound like a real rig.
To summarize, the preamp section generates a tonal flavor and allows for tone sculpting, and the power amp section makes it loud(er). Obviously, this is a highly simplistic way of looking at guitar amp circuits, but this is an important fundamental concept to understand before we get into talking about preamp pedals.
Now that we know that preamps produce the tone and power amps produce the volume, what are we to make of so-called preamp pedals that are on the market today? To be perfectly honest, it can be a confusing proposal. By nobody’s fault, the word “preamp,” when used in a pedal context, has become somewhat amorphous. But It is important to understand what the intended use of these pedals are, to ensure that you are using it in the correct application. Here are a few examples of the different applications of certain preamp pedals:
Victory’s Preamp Pedal Series
The preamp pedals that are released by Victory Amplifiers are designed to act as your rig’s sole preamp section. In fact, contained within these solid, rugged units is a replication of the same preamp sections (including tubes!) that are contained within the full combo/head versions of that same amp from Victory’s line of products. In Victory’s own words, “please be aware that it is NOT like a ‘normal,’ everyday overdrive pedal. It is an all-valve preamp capable of far richer, amp-like tones and is primarily designed to sit in place of – not in front of – your guitar amp’s existing preamp. You can use it in to the front of your amp if you want – it won’t damage anything and you might love it – but it’s not how we designed it to work best.”
To achieve the correct application for these pedals, you have a couple different options. The first is to run the preamp pedal directly into a clean, uncolored power amp. These options are usually found in rack mount solid-state configurations, though companies such as ValveTrain make a tube-powered combos that contain a speaker and an uncolored power amp. The other is to utilize the amp head or combo amp that you already have and plug the preamp pedal into your amp’s effects loop. This allows you to utilize the power section of your amp while bypassing your amp’s preamp section, and thus using the Victory preamp pedal as your amp’s preamp.
The justly fêted Benson Preamp pedal is essentially the circuit of the Benson Chimera 30 amp with FETs replacing the tubes. On paper, this sounds like a very similar proposition to the Victory preamp series, but this pedal, though also called a preamp, is not designed to be your amp’s sole preamp/EQ source. This is designed to be run into your amp’s existing preamp (like any pedal on your pedalboard) to genuinely replicate the overdrive of a Chimera 30. You may find that this type of preamp pedal (i.e. one that is essentially to be used as an overdrive pedal) is among the more common applications for pedals that are branded as preamps.
JHS Clover Preamp
The JHS Clover is a modified reissue of the Boss FA-1 FET Amplifier. The purpose of this preamp pedal is to give you additional EQ (and boost) control over your amp’s tone. Is your Fender amp sounding a little too scooped? Use the Clover to add some mids. Want to add some bottom-end to your Vox? Use the Clover to add some bass. You get the idea.
As you can see, these three examples are all called preamps (and are all super awesome), but they are manufactured to be used in different applications. One is designed to be your sole preamp, one is designed to give you a certain amp’s overdrive tone into your existing amp, and the other is a versatile EQ and boost. Hopefully after reading this, you can spot the differences in these types of preamps and be sure to seek out the right one for your needs.