Amps

An ‘ukulele player must shop for an amp as well as a pickup to be able to “plug in“. This is something that you should take time on. Do your research. Try amps, talk to musicians, etc. In general – unless you are looking for a different tone – an acoustic guitar amplifier is probably the best bet for plugging in your ‘ukulele. The good thing about looking for the perfect acoustic amp is that there isn’t a huge selection to choose from. I can’t tell you what is best because we all have a different sound in our heads that we are trying to reproduce. The only way to find a great amp is to have an idea of the desired sound and start trying them. Here is a cross-section of an acoustic amplifier so you can learn and narrow down your search.

Amp – The amp itself is not the whole box, but just the circuit that lives in there. This circuit is what boosts the signal and determines the power of the whole unit. Just for the ease of things I’ll (and you can too) call the whole setup an “amp“, but the word is really referring to the circuit that gives the big box its name.

Amp Head – This is a smaller box that does not contain speakers, just the amp circuit. You need a speaker cabinet to get any sound.

Speaker Cabinet – The speaker cabinet is a separate wooden box that holds the speaker(s). On acoustic amps, usually the amp and cabinet are all one. If you have just an amp head you will need a speaker cabinet to make noise. The size of these speaker cabinets vary, but the most well known size is the Marshall half stack with 4 12 in. speakers (think Jimi).

Watts – How many watts an amp is rated for determines its power and loudness. A 60 watt amp is going to be louder than a 30 watt amp. Around 100 watts is the power that is needed to play in a full band. Much beyond that and a PA system is going to make more sense.

Effects – Sometimes amps come with onboard effects. Delay, reverb, and chorus are the most common. These are usually controlled by one or two knobs that change the parameters (time, feedback, depth, etc.).

Speaker – An amp can have any number of speakers in it. The speakers themselves are cones housed in a solid shell. The cone is attached to a big magnet that is turned on and off very quickly. The vibrating of the magnet moves the cone, and likewise the air, making sound waves. A big speaker is called a driver. The bigger diameter a speaker has the more bass response you will hear. Little tiny speakers are called tweeters. They produce lots of treble. Most of the time you will see a driver and tweeter combination to get a more balanced sound.

Gain – The input gain is controlled by a knob. The gain controls how much signal is being put through the amp circuit. Turning up the gain will boost the amp volume considerably, but it also makes the tone sharper. On electric guitar amps the gain controls the distortion. You will have a hard time distorting an acoustic amp, but they work on the same principle. You want the gain as high as it will go without starting to clip or distort.

EQ – Equalization is the control of individual frequencies. The EQ is usually controlled by three knobs: bass, mids, and treble. Other interfaces include two knobs (bass and treble), one knob (bass on one side treble on the other), or sliders (with more specific frequencies). I find that for my ‘ukulele I have to cut down the mids to avoid feedback.

Tube vs. Solid State – A “tube amp” is an amp that use tubes (clever) in its circuit to boost the signal. Tube amps fatten up the signal more than solid state – they are also more expensive and heavy. A solid state amp uses transistors to boost the signal for a more clean sound. Most acoustic amps on the market are solid state.

Inputs – There are two common types of inputs that can be found on an acoustic amp: ¼ in. and a XLR. The ¼ in. is what you plug your ‘ukulele into and the XLR can be used for a mic. Sometimes you will be able to add audio from an outside source via an auxiliary input. This is for connecting your ipod or CD player so that you can play along.

Outputs – The main output would be the speaker, but sometimes you will want to send the signal elsewhere. Some common outputs are:

Recording out for going straight into the PA or mixing board.
Headphone out that allows you to plug in headphones without blowing them or your ears out.
Effects loop for adding effects after the signal reaches the amp. This is said to sound better than having the effects in line on the way to the amp.

Notch Filter – This is a knob for reducing the frequencies that cause the ‘ukulele to feed back. Turning this knob sweeps through a window of middle frequencies, each of which are cut down when selected. With this technology you can practically stand in front of the amp at full blast and not feed back.

DI – A DI or preamp is not related to the amp specifically, but can improve your tone. A preamp balances and boosts the incoming signal so that the amp has more to work with. It is not uncommon for acoustic amps to have their own built in preamps.

Headroom – Is how much you can turn up the volume on the amp before it distorts. Headroom goes hand in hand with watts. More watts = more headroom. Since most of the time you will want a clean sound for your ‘ukulele the more headroom you have the better. For example, you crank a 30 watt amp up all the way and it starts to distort, if you were playing a 100 watt amp that loud you would have more headroom and the signal would not distort.

Clip – Sometimes an amp has a “clip” light. This shows you when the incoming signal is overloading the circuits. If the clip light goes on even when you play softly, try turning down the gain.

There is no right answer when searching for the perfect amp. The sound in your head is the only thing that can guide you. Talk to as many people as possible, learn as much as you can, and try all the amps in the music store.

Some of the most respected brands are: Fishman, Roland, LR Baggs, and Fender.

The nicest amp I have played into is the Roland AC-90. I tried it with my Kamaka tenor with a K&K passive pickup (the Big Spot I think). It just really worked for me. The amp has two channels, one for your instrument and one for a mic, delay and reverb, chorus, notch filter, a mute switch, etc.

A PA system is also a viable option for amplifying your ‘ukulele. Since most players are just looking for a clean volume boost a PA could be the best bet for you.

Here are some more in depth resources about acoustic guitar amps and amplification. (these go into details on pickups as well)

http://www.museweb.com/ag/amp/ag_amp.html
http://www.acousticfingerstyle.com/zenart.htm