Ashdown Engineering Acoustic Guitar Amplifiers

About Acoustic Guitar Amplifiers

An acoustic guitar amp has one job that sets it apart from every other amp in your signal chain: get loud without changing how your guitar already sounds. Where an electric combo amp is built to shape your tone - adding midrange, breakup, and character - an acoustic amp is built to disappear. Think of it less as an instrument and more as a small, guitar-friendly PA system. Below is a quick tour of how they work, why a dedicated acoustic amp beats running into your electric rig, and what actually matters when you're choosing one.

What Makes an Acoustic Amp Different From a Regular Guitar Amp?

If you've only ever played electric, this is the part worth understanding. An electric guitar amp is voiced - its preamp, EQ, and especially its speaker are all tuned to color the signal. Guitar speakers deliberately roll off the highs above ~5kHz and the deep lows, which is exactly what makes an electric guitar sound "right." Push a mic'd-up acoustic or a piezo pickup through that same amp and you get the opposite of what you want: boxy, honky, and thin, with all the air and string detail stripped out.

Acoustic amps flip every one of those design choices:

Flat, full-range response

Instead of a sculpted midrange hump, a good acoustic amp aims for a relatively flat frequency response across the whole spectrum - closer to a studio monitor than a guitar amp. Your guitar's natural body resonance and pick attack come through intact.

A speaker built for the full picture (usually with a tweeter)

Most acoustic amps pair a full-range woofer with a dedicated tweeter or horn to reproduce the sparkle and "air" up top that a guitar speaker simply can't. That hi-fi quality is why a Loudbox or AER sounds like your guitar, louder - not like your guitar through a wall.

Tons of clean headroom

Acoustic amps are designed to stay clean and uncolored even at volume. There's no sweet spot where it starts to break up - that's a feature, not a limitation. Acoustic guitars have huge dynamic swings (a hard strum has way more transient energy than an electric), so the amp needs headroom to reproduce that without clipping.

Why Not Just Use My Electric Amp?

You can - for quiet practice it's fine. But you'll run into three things fast:

• It won't sound natural. A transparent acoustic tone through a voiced electric amp loses the woody, open character that made you want to amplify the acoustic in the first place.
• Feedback. A hollow body plus a guitar amp's resonant midrange is a recipe for runaway feedback the moment you turn up. Acoustic amps include tools specifically to fight this (more below).
• No vocal/mic support. Singer-songwriters need a mic channel - electric amps don't have one.

The short version: an electric amp is part of your sound; an acoustic amp is a reproduction system that keeps your sound honest. Browse the full lineup of acoustic guitar amplifiers to see the range, or compare against standard combo amps and the broader guitar amplifier category.

Is There Such a Thing as a Tube Acoustic Guitar Amp?

Almost never - and once you understand the goal, you'll see why. Tubes are prized on the electric side precisely because they color and compress the signal in a musical way. That's the exact opposite of what an acoustic amp is trying to do. So the category is overwhelmingly solid-state, and increasingly Class D (switching) power, which is light, runs cool, delivers loads of clean headroom, and sips power - perfect for battery and busking use.

Genuine tube acoustic amps do exist, but they're rare boutique designs (the Rivera Sedona is the classic example), and they tend to blur into acoustic-and-electric hybrids rather than pure acoustic amps. A few modern amps use a tube in the preamp for a touch of warmth while keeping clean solid-state power - but if someone's selling you a fully cranked tube amp "for acoustic," they've misunderstood the assignment. Want tube warmth on your acoustic? It's usually added in the preamp or with a pedal, not baked into the power section.

How Many Watts Do I Need?

Acoustic-amp watts aren't electric-amp watts. Because these are solid-state and built for headroom, the wattage numbers run higher than a tube electric amp - a 60-watt acoustic amp is genuinely loud and stays clean. Rough guide:

• Home & practice: 20–40 watts is plenty.
• Coffeehouses, open mics, small rooms: 50–90 watts gives you headroom to fill the space without distorting on hard strums.
• Bands, outdoor, larger venues: 100 watts and up - or, just as commonly, use a smaller amp as your personal monitor and send a direct signal to the venue's PA (see DI output below).

When in doubt, buy a little more headroom than you think you need. A clean amp loafing at half-volume always sounds better than a small one straining.

What to Look For

Multiple channels and an XLR mic input

The single most useful feature for singer-songwriters. A two-channel acoustic amp with a combo XLR/instrument jack lets you run your guitar on one channel and a vocal mic (or a second player) on the other. Models like the Boss Acoustic Singer and Fishman Loudbox Artist are essentially miniature PAs built around this idea.

Feedback control

Because acoustic bodies resonate, anti-feedback tools are a core differentiator. Look for a notch filter, a phase/polarity invert switch, and sometimes a low-cut/contour - they let you crank up without the howl.

Onboard effects (reverb & chorus)

A little reverb makes a mic'd or pickup-equipped acoustic shimmer, and chorus adds width - both also flatter vocals. Most quality acoustic amps include them; some add delay and tap tempo.

A direct (DI/XLR) output

A balanced DI out lets the amp double as a stage monitor while feeding a clean signal to the front-of-house mixer or your recording audio interface. For gigging, this is the feature that turns a small amp into a big-room rig.

Portability, battery & Bluetooth

For buskers and travelers, look for battery power and Bluetooth streaming (jam along to backing tracks). The Roland AC-60 and battery-capable AER and Fishman models built their reputations here.

Acoustic Guitar Amp FAQ

Can I use an acoustic amp for electric guitar?

Yes - you'll get a very clean, uncolored sound with no natural overdrive. It can be a nice clean platform for pedals, but it won't give you amp-driven crunch or that classic electric breakup. It's the mirror image of the problem above.

Can I plug a microphone into an acoustic amp?

On most two-channel models, yes - that's what the XLR channel is for. It's a big reason acoustic amps double as compact PAs for solo performers.

Do I need a special amp for an acoustic-electric guitar?

If your acoustic has a built-in pickup/preamp (piezo, magnetic, or a blend), an acoustic amp is exactly what it's designed for. Piezo pickups in particular have a wide, bright frequency range that an electric amp's speaker can't reproduce cleanly. Pair it with a quality acoustic guitar pickup and you're set.

Acoustic amp or go direct into the PA?

Both have a place. An amp gives you a personal monitor and on-stage tone control; a DI to the PA gives the room a clean, consistent signal. Many gigging players do both - amp on stage, DI to front of house.

Explore the full range of acoustic guitar amplifiers on Equipboard to see specs, find out which models the pros actually use, read community reviews, and compare prices across retailers. Pick the amp that lets your acoustic sound like itself, only bigger.