The complex interaction of sounds from the guitar’s body, top, strings, and other components results in the tone of an acoustic guitar. And as you play, this interaction evolves to create that rich, woody sound we love.
Unfortunately, the standard under-saddle piezo pickups installed on most guitars simply can’t reproduce this resonant complexity.
To get the natural sound of your acoustic when you put it through an amp, you need a preamp that boosts low-level signals, resulting in better-quality audio. They often have a feature to cut out unwanted frequencies which gives you a cleaner tone too.
Here, we’ll look at the best on the market.
Best Acoustic Guitar Preamp: Product Guide
LR Baggs Session Acoustic DI Preamp Pedal
The LR Baggs Session Acoustic DI preamp pedal will get you the perfect sound out of your acoustic guitar, whether you are playing live or laying down tracks. You can easily dial in a professional, high-quality tone with a set of single-knob processors.
The saturation control makes it easy to dial in the kind of rich warmth used by experienced studio engineers in post-production to make acoustic guitars sit in the mix perfectly.
Then there is the multiband compression, which allows you to add smooth polish with just a twist of a knob. With the high pass filter (located on the side) you can also cut out the boom.
The Garret Null notch filter variable helps you tame the resonance that generates feedback, and, just in case, there’s also a phase switch.
- Lets you fully expand your live tone with saturation and compression inspired by the post-production techniques of experienced studio engineers
- EQ smoothes out common problem frequencies
- Garret Null notch filter kills resonant feedback
Fishman Aura Spectrum
If you have a little more money to spare, the Aura Spectrum from Fishman is a superb high-end option.
It does everything you’d expect from a preamp and DI, but in addition, benefits from Fishman’s Aura Acoustic Imaging Technology which accurately reproduces the sound of your instrument as if it was miked in a professional studio.
Aura uses digital algorithms to create an image of the natural sound that microphones capture in a professional studio. This image is played through an amp of a mixer or PA blends in combination with your instrument’s pickup to produce a noticeable improvement to your amplified sound.
It also includes a 3-band EQ, one-knob compressor, automatic feedback suppression with up to 3 notches, a chromatic tuner, effects loop, plus a balanced XLR DI.
- High-quality acoustic preamp and DI
- Aura Acoustic Imaging technology gives you a vivid and natural tone
- Packed with features (tuner, effects loop, 3-band EQ)
If you’re on a budget and want to keep things simple, the BOSS AD-2 should definitely be considered.
Compared to the others, it’s modest in looks, but don’t be fooled. Despite its size and appearance, it will do everything you need.
With it’s ‘Acoustic Resonance’ effect, the AD-2 reproduces the complex resonance characteristics of your guitar’s natural, unplugged tone. It also lets you add studio-quality reverb via it’s ‘Ambience’ effect that’s perfectly optimized for acoustic guitar.
In addition, you get a notch filter for feedback control and a balanced DI out for direct connection to a PA. convenient mute function for tuning and switching guitars.
- Acoustic Resonance effect reproduces your guitar’s ‘unplugged’ natural sound
- Ambience effect lets you dial in studio-quality reverb for any performing environment
- Notch filter for feedback control
- Superb price
This pedal has 3 band EQ, and a processor button to clean up your signal, ready for further amplification.
It features a ‘sonic maximizer’, which automatically adds clarity and definition to your instrument, and a phase reverser which can fix any out-of-sync sounds.
- Tightens up the frequencies easily and accurately due to its extensive selection of controls
- The ‘sonic maximizer’ feature produces a boosted, clear preset at the switch of a button
- Not too expensive
Tech 21 SansAmp Para Driver DI
The Tech 21 is perfect for those who are playing through passive pickups. It actively balances out some of the weaknesses of piezo pickups to give a warmer and more natural sound.
This is a versatile product, which combines three-band EQ with a mid-shift control for extra equalization options.
There’s also an overdrive effect, should you want a bit of an edge or full on dirtiness. As well as working for acoustic guitars, you can use this for your electric guitars or bass guitars, making it a more versatile piece of kit.
- It can boost and cut 12db with dedicated buttons for quickly switching between lead and rhythm
- It can also be used with solid-body instruments, making it potentially more useful and versatile
- There’s a full range of tone-shaping knobs including a mid-shift control, so you can set your mid-range for extra controllability
Radial Tonebone PZ
The Radial Tonebone has some interesting add-ons. There are pre and post-EQ outputs and an effects loop send and return, which makes it ideal for combining with other pedals.
There’s also a boost option, a notch knob for feedback control, and three-foot controls for boost, toggle, and mute.
- Very transparent, it allows your guitar’s natural harmonics to come through while tweaking it slightly through the EQ settings, filters, and additional DI features
- It has two channels for making the most out of your pickups or a pickup plus a mic, although it’s not designed for use with multiple instruments at once
Benefits of Using a Guitar Preamp
Boosting Low Signals
Boosting low signals is often the primary reason people turn to preamps. If the signal from your guitar is low, it’s going to get distorted as soon as you try giving it any volume. A pre-amp gives you the option to increase the volume of your signal so that it travels to the amp at a decent level.
Adjusting the Signal
Sometimes, you might want to play around with the tone controls on your guitar. Preamps allow you to adjust the signal that’s coming through (i.e., your EQ). Need a bit more bass? Whack up the lows. Too tinny? Turn the highs down. You get the picture.
EQ controls are normally three bands: hi, mid, and bass. However, some pedals offer extra controllability by having five options. This enables you to really fine-tune things. Some pedals don’t have five-band EQ, but they do have a mid-range shifter, which means you can adjust the frequencies that your controls are directing.
Cleaning Up the Signal
Acoustic guitars are prone to getting feedback. Pre-amps include filter controls (called ‘notch’ filters) which eliminate excess noise from your signal by narrowing the band of frequencies that are causing feedback. Once you get rid of these unwanted noises, your guitar will be closer to being like its unplugged self.
A lot of these pedals offer feedback suppression via a footswitch. This is easier and more convenient than a notched knob, as you can do it mid-performance without crouching to the floor.
Blending Multiple Signals
Another useful benefit is for blending signals. You might want to use a pickup and a microphone on your guitar, and these will need to be in sync. A preamp combines these two signals and creates one output to send to your amplifier.
Controlling Your Sound at Gigs
When you gig, your signal is controlled by a sound engineer who probably isn’t familiar with you or your style. Considering all the variables at play, how could they possibly know what’s right for you? Carrying a small device that allows you to set your EQ, reduces feedback, and also boosts your signal is the key to being your best when you step on stage.
Buying Guide – Key Considerations
Ok, you know the benefits. What are the things to look out for when buying one of these gizmos? Let’s take a look.
Type of Pickup
There is a lot of confusion about the difference between passive and active pickups.
If your guitar has a built-in pickup, it’s likely that it’s an active pickup – these pickups tend to include a preamp already but as we mentioned earlier, they’re often inadequate. The addition of an external preamp will increase your tonal options and reduce any unwanted noises or frequencies. Look out for something with five-band EQ, to increase your tonal control.
If you have a passive pickup – the kind you attach yourself – the signal it produces will be lower than you’d require for a quality tone. You’ll need a preamp to boost this, and to reduce any feedback that it may cause.
Magnetic pickups are very similar to those used in electric guitars. The more EQ and frequency settings you have here, the more you’ll be able to edit your sound until its as you think it should be.
What You Play Through
Mixing desks, with XLR inputs, are what we plug into at gigs. In situations like these, a preamp will act like a DI box, to change the high impedance signal from your guitar into a low impedance signal, and to convert the connection to an XLR which can go into a desk.
When you’re plugged in, you can then use it to shape your tone in a way that the mixing desk alone cannot do as effectively, as it’s designed with a broader range of instruments in mind.
Even so, many guitarists still choose to use an additional preamp, for a higher level of controllability. Also, if you’re using a passive/piezo pickup, you’ll still require the signal boost of a preamp before you send your sound towards the amp.
So, Which Should I Buy
Our pick of the bunch goes to the LR Baggs, a classy pedal that’s been designed to bring studio-quality tone to your live rig. It allows you to fully expand your live tone with saturation and compression inspired by the post-production techniques of the most experienced studio engineers.
Our premium pick goes to the Fishman Aura Spectrum, an amazing bit of kit that gives you a ‘studio-miked’ sound from your under saddle or sound hole pickup, to enhance the sound of your acoustic guitar.
The best budget preamp is the AD-2 from BOSS. A superb pedal, with its ‘Acoustic Resonance’ effect that reproduces your guitar’s ‘unplugged’ natural sound really well.