The word "preamp" can meet a lot of different things, depending on the context. Audio engineers tend to think of a preamp as a device for powering a microphone and/or amplifying its signal prior to recording, while audiophiles think of a preamp as the thing that comes before their power amplifier, featuring volume and equalization controls, and some switching functions.
In guitar speak, a preamp can be an integrated section of a guitar amplifier's circuitry, which (much like the stereo preamp) often contains tone and gain controls, or it can be a similarly functional external unit meant to enter the signal chain before the guitar amp, running either straight in the front, or in the effects loop.
Such a device would typically serve as the main source of EQ, drive, and other tonesculpting capabilities. Many older guitarists associate the term "preamp" closely with formerly ubiquitous eighties rack units from A/DA, Marshall, Mesa/Boogie, and other companies. Current guitar preamp options are much more varied, however, and the most convenient choice for the modern pedalboard-bound guitarist is probably a pedal preamp.
So, you might be thinking at this point, if a preamp is just a pedal that has tone, gain, and volume controls, what makes it different from a regular old distortion pedal with EQ? Well, the answer is complicated. Some pedals marketed as preamps really have nothing more to offer than a standard dirt box layout with basic EQ, while other, seemingly similar, units are much more deserving of the moniker, serving as a complete sound solution that can work equally well in front of a guitar amp, clean power amp, in an effects loop, or even direct into a recorder or PA system.
These types of preamplifiers can be superb tools for traveling guitarists that need a powerful, portable gigging device that can serve as a complete tone foundation, providing a consistent sound no matter the backline or recording scenario. Here are a few of our top picks for fully-featured pedal preamps.
AMT Electronics SS-11A Preamp
AMT Electronics originated in Russia, and the company has recently opened an American branch, AMT Electronics USA, to expand its reach worldwide. The company offers a broad and colorful selection of amps and effects, but its line of tube-based pedal preamps is largely responsible for building AMT's formidable reputation among guitarists. With an incredible range of functions thoughtfully laid out in a very compact enclosure, AMT's guitar preamps are perfect for players seeking a portable, reliable, and great sounding base on which to build their tone. One of the company's most popular models is the SS-11A, which focuses on classic, medium-gain rock tones, with three separate channels for a wide range of dual 12AX7-powered clean, crunch, and lead sounds. Unlike many preamps that boast of being tube-powered, the SS-11A's overdrive exhibits a genuinely dynamic, amp-like, feel and tone. Even more surprising than the quality of its overdrive, though, is the vibrance and complexity of its cleaner tones, which sound rich and musically compressed, contrasting with the thin, sterile sounds one might typically expect from a lesser pedal pre. EQ, gain, and level controls are extensive, to say the least, and it even features a proper effects loop. And because it's a real preamplifier, and not just a distortion box, the AMT SS-11A can be used either front of an amp, or direct to a console or recorder, with dedicated, selectable outputs. Its "TO MIX" output has an excellent sounding cabinet simulator that uses guitar cabinet impulse response modeling to get some of the richest direct guitar tones I've ever heard.
Effectrode Blackbird Vacuum Tube Preamp
Effectrode's tube-based guitar effects and preamps often seem to incorporate elements of pro audio and audiophile design, not typical of guitar pedals, which contributes to their unique sound and functional qualities. One of the company's finest products is the Blackbird Vacuum Tube Preamp, a pedal preamplifier that begins with a replicated "blackface" Fender tube circuit on the glassy, rich sounding clean channel, and uses four-stage, all-tube clipping on the drive channel to produce an abundance of tones reminiscent of more modern, higher gain amps from Dumble and Soldano. Whether you're after warm, natural drive, thickly saturated metallic sounds, or something in between, it can be easily conjured up. Each channel has a dedicated three-band EQ, based on the highly interactive tone stack designs of blackface-era Fenders, and further tonal variety can be had by swapping tubes and/or adjusting bias, either with an external switch, or an internal trim pot. The Effectrode Blackbird's audiophile quality, transformer-balanced output allows it to be connected to professional recording equipment or a power amp for complete tonal flexibility, whatever the recording or gigging situation.
Custom Tones Ethos Overdrive Preamp
Dumble-flavored overdrive pedals are a pretty hot item in the boutique pedal world right now, with many builders attempting to capture the essence of those fabled, and legendarily expensive, amplifiers in a convenient, relatively affordable stompbox. The Ethos Overdrive Preamp from Custom Tones, is at the top of the heap, with a sonic signature based on an '80s Dumble Overdrive Special. It convincingly captures much of the Dumble majesty with a highly dynamic selection of sounds that range from sparkling, three-dimensional cleans, to fat crunch tones, and silken, liquid saturation. A pair of independent channels, with a preamp boost on the overdrive channel, extensive equalization options, and three voicing switches will inspire hours and hours of tweaking, bringing forth a staggering array of sounds and colors. The Ethos is designed to be connected to an amp, or direct to a mixer or recorder. When connecting it to an amplifier, you can choose to engage its unique Guitar Amp Compensation circuitry, which compensates for the characteristic sounds of common amps from Marshall and Fender, allowing the Ethos to do its thing unimpeded by those amps' voicings. Its power to generate lively, realistic tones is such that the Ethos can even be used quite effectively straight into a solid-state, PA-style power amp, making it an incredibly flexible companion for the gigging guitarist.
Tech 21 Character Series
One of the most affordable and versatile options for proper pedal-based guitar preamplifiers comes from Tech 21, a pioneering company in the preamp game. Tech 21 basically invented analog amp modeling when it released the original SansAmp in 1989, a pedal-sized box with several different modeled amp tones intended for use as a direct recording interface. The company's very popular Character Series continues in this tradition with a wide range of analog pedal preamps that model amps from Fender, Marshall, Mesa, Orange, Hiwatt, and more.
These compact preamps are perfectly at home being used as drive pedals running in front of a guitar amp, but they really come alive when pushing a big, clean power amp, or connected directly into a recording console with the speaker emulation switch activated. Tech 21's speaker modeling has always been top-notch, and the Character Series further improves upon the technology with emulations of specific speakers. For instance, the Leeds preamp includes Fane-style speaker emulation, while the Blonde model includes a very convincing vintage Jensen emulation. Along with a full range of drive, output, and equalization controls, this feature earns the Tech 21 Character Series the maximum bang-for-the-buck award.
A true guitar preamplifier pedal—as opposed to just a standard OD box—can be a very versatile tool for gigging guitar players, especially those who travel frequently and are often at the mercy of rented amplifiers. They are also very useful for any player who records regularly, and values the ability to just plug in, get a tone, and start laying down tracks, without the time and trouble required to set up cabinets, microphones, and everything else that goes along with recording a live amp. And given that many excellent pedal preamps cost about the same, or less, than some boutique overdrives, it's clear that any guitarist considering a new OD or distortion should take a close look at one of the new breed of preamp pedals.