If you’re lucky, plugging straight into an amp will make your ukulele sound great.
But more often than not, you’ll be hindered by the quirks and character of your pickup and the room. This results in a less-than-perfect sound.
The Gold In, Gold Out Rule
If you start with a great sounding pickup, there will be much less to fix along the way. It’s way easier to tweak a sound that’s already 90% of the way there than to try and manipulate a bad sound into greatness.
Be sure to do some homework on pickups and keep your expectations realistic if working with sub-par equipment. If your starting sound is garbage, you’re better off spending your money on a new pickup, not a preamp.
What Does a Preamp Do?
A preamp, in a limited sense, is a circuit that boosts and matches your signal with the input of an amp or PA. In most applications, an acoustic preamp comes with several tools to help you tune up your sound.
It Balances Impedance
If your pickup has an output impedance that is higher than than the input impedance, you’ll have an impedance mismatch.
A mixer or amp usually expects a low-ish impedance source at its input. For instance, an electric guitar has around a 1-2kΩ output impedance. A microphone is even less, at 150-600Ω.
Contrast this to a typical passive ukulele pickup which provides somewhere around 1MΩ (that’s one million ohms)! The mixer isn’t able to handle such a large amount of resistance and this results in “loading” the pickup circuit.
When there’s an impedance mismatch like this, a handful of bad things happen, such as: low volume, loss of low-end resulting in a thin, “quacky” tone, and noise.
A preamp converts the pickup’s high output impedance to a low output impedance that the mixer can process better.
All that to say: a preamp is vital if your pickup is passive. An active pickup will already have a more reasonable output impedance (my LR Baggs Five-0 is 3.6kΩ), but can still benefit from the other features a preamp usually provides.
Check the spec sheet of any gear you’re looking at buying to see if it can provide a high enough input.
It Boosts the Signal
Impedance mismatching aside, a pickup often produces a weak signal. This requires cranking the knobs on a mixer or amp way up to get a reasonable volume. Pushing the controls like this doesn’t create the best possible sound.
Fortunately, a preamp has a gain control. This increases the input volume – or circuit sensitivity – which ups the output many times over.
Depending on the preamp, you want to set the gain control so that on your very hardest strumming, the signal clips slightly. This gives you the most possible boost with a reasonable amount of headroom left over.
It (Usually) Provides EQ Control
An incredibly useful feature most preamps have these days is an EQ section. It’s possible that your pickup outputs a perfect sound, but not likely, which is why I always insist on EQ controls in a preamp.
Equalization sculpts the tone of your signal. It allows you to boost or cut certain frequencies.
I wrote more about EQ on my page about ukulele pickups:
Getting the most out of your pickup (scroll down to “Tweak the EQ”)
Do I Need a Preamp?
It depends on your situation and the impedance of your pickup and amp or PA.
If you have an active pickup, you can usually run without a preamp. However, you might find the extra control a preamp gives you in volume and EQ is worth the hassle and money.
If you have a passive piezo pickup, the short answer is: YES, you need a preamp. These pickups can sound great, but they need an optimized environment to really shine.
That said, when the input is high-impedance, you might not need a preamp.
A high-impedance input can come in the form of an acoustic amp or as a high-grade, piezo-intended stage direct box. This type of direct box is few and far between so don’t count on them at a gig unless you bring it yourself.
Preamps come in many flavors and the options can be overwhelming.
If at all possible, try your ukulele with any preamp you might want to buy. The way your pickup interacts with the circuit of the preamp is likely different than mine.
It’s subtle, but interesting to hear the difference in sound between two pedals that do almost the exact same thing. I’d expect this variety in signal coloration from any two preamps.
Preamps I Like
I’ve been plugging my ukulele in and performing onstage for a decade and a half. For the most part, I’ve “been there, done that” and have found what works best for me over the years. That’s exactly what I’ll recommend to you. It’s not that other preamps are BAD, I just haven’t used them or choose not to.
Personally, I require a semi-parametric EQ section in any preamp I use. It’s the hands-down best way to fine-tune the sound of your pickup and make adjustments depending on the room. This is an EQ that lets you precisely select which frequency to boost or cut (other EQs have fixed frequencies – a less precise approach).
Currently, my favorite out of the six or so dedicated preamps I’ve tried is the Tech 21 Q\Strip.
It’s not an acoustic preamp, per se, but provides the key requirements and great sound. The input is rated at 4.7MΩ, which is sufficient for most passive pickups, there’s ample amounts of volume, a DI output, and two semi-parametric EQ bands – along with high and low EQ controls. And it’s small.
The industry standard for middle-of-the-road preamps is the Para DI by LR Baggs. This is the easiest unit to recommend to anybody since it’s tried and true.
If you want something more fancy, I like the LR Baggs Venue DI. Though the tuner kind of sucks and, for the space it takes up, these days I’d probably just get the Para DI since the circuit is essentially the same.
Many preamps (including the Para DI, Venue, and Q\Strip) have an XLR output that sends a line level signal. This is commonly known as a DI – or direct input/injection. By utilizing a DI output you can provide a strong signal right to the mixing board and not worry about signal degradation along the cable.
This can be great if you play through a PA a lot. It reduces the need for an extra DI box (like this). If you play mainly through an amp, you might want – or need – to use a 1/4″ cable anyways and the DI feature will be wasted.
The sound that is produced by the preamp will be basically identical whether using XLR or 1/4″. The only difference is that the DI is output at a fixed “line” level, which is +4dbu and very loud. The 1/4″ output is at a lower volume and will require you to crank the level to get a line level-like output signal. Often a pickup that is quiet over the 1/4″ cable will be plenty loud when using the DI out.
My main rig for the past few years has been the HX Stomp from Line 6. It has a 1MΩ input, which isn’t enough for a lot of passive pickups, but could be enough depending on your model – especially if you have an active pickup. It does everything and is quite expensive. I don’t recommend it for hobby players, but if you want the best for performing, I haven’t found anything better.
Everybody has their own needs and preferences with gear. As such, there are many options suitable for an ukulele preamp. However, finding them is difficult. They seem to get buried under the hype of electric guitar pedals.
I figure it can’t hurt to put together as comprehensive a list as possible of acoustic instrument preamps. “EQ” assumed to be fixed-band based (parametric shown as “para-EQ”). Possibly better options for uke in bold.
- Audio Sprockets Tonedexter – ($399) High/low EQ, notch, Wavemap for creating impulse responses by plugging in a mic
- BBE Acoustimax – ($149) Para-EQ, mute, notch, phase, sonic maximizer, FX loop, DI
- Behringer ADI21 V-Tone – ($29) Para-EQ, DI
- Boss AD-2 – ($99) Ambience, notch, acoustic resonance, mute
- Boss AD-10 – ($334) Two-inputs, Para-EQ, compression, ambience, delay/chorus, anti-feedback, acoustic resonance, boost, tuner, FX loop, DI
- Fishman Aura Spectrum DI – ($349) EQ, compression, Aura imaging, tuner, phase, FX loop, anti-feedback, DI
- Fishman ToneDEQ – ($299) Reverb, delay, chorus, flanger, tremolo, phase, compression, EQ, boost footswitch, DI
- Fishman Platinum Pro EQ/DI – ($299) Para-EQ, low-cut, compression, tuner, boost, notch, phase, FX loop, DI
- Fishman Platinum Stage EQ/DI – ($149) Para-EQ, boost, phase, low-cut, DI
- GMF Al1 – ($99) High/low EQ, phase, DI
- Grace Design BiX – ($295) High/low EQ, boost, mute, DI
- Grace Design ALiX – ($695) Para-EQ, low-cut, boost, mute, phase, DI
- Grace Design Felix – ($1075) Two-channels, Para-EQ, low-cut, mute, boost, phase, FX loop, 48v phantom power, DI (2)
- JHS The Clover – ($199) EQ, low-cut, DI
- K&K Pure – ($99) EQ
- K&K Pure XLR – ($177) EQ, phase, DI
- Lehle Acouswitch IQ DI – ($599) Two-inputs, para-EQ, mute, boost, FX loop, DI
- LR Baggs Gigpro – ($99) High/low EQ, phase, belt clip
- LR Baggs Mixpro – ($169) Two-inputs, high/low EQ, 48v phantom power
- LR Baggs Venue DI – ($299) Tuner, para-EQ, boost, notch, phase, FX loop, DI
- LR Baggs Session DI – ($249) Notch, saturation, compression EQ, low-cut, mute switch, phase , DI
- LR Baggs Para DI – ($189) Para-EQ, notch, FX loop, phase, DI
- Mesa/Boogie Rosette – ($379) Para-EQ, low-cut, notch, boost, mute, phase, FX loop, DI
- NUX Stageman Floor – ($149) 3-band EQ, notch, chorus, reverb, FX loop, DI, headphone out
- Orange Valve Pre – ($899) Two-channels, para-EQ, reverb, phase, mute, 48v phantom power, FX loop, DI
- Pigtronix Bob Weir’s Real Deal – ($279) Two-input, crossover, phase, anti-feedback, 48v phantom
- Radial AC Driver – ($149) Two-inputs, low-cut, notch, phase, mute, DI
- Radial Tonebone PZ-Deluxe ($249) Para-EQ, low-cut, phase, mute, boost, DI
- Radial Tonebone PZ-Pre – ($409) Para-EQ, low-cut, notch, phase, boost, mute, FX loop, DI
- Tech 21 Q\Strip – ($249) Para-EQ, high-cut, low-cut, DI
- Trace Elliot Transit A – ($299) Reverb, delay, chorus, boost, tuner, phase, notch, EQ, DI
- Zoom AC-2 – ($199) EQ, boost, tuner, reverb, anti-feedback, DI
If one of those doesn’t meet your needs you’re in serious trouble!