In this guide, we're going to take a look at one of the most underrated yet powerful pieces of gear a guitarist can buy. They may not be as discussed as some of their counterparts in the pedal world, but ABY boxes are used by countless professional and touring musicians all over the world.
An ABY pedal could be the secret weapon that takes your tone to the next level!
If you own a couple of guitar amplifiers and want to use both of them live, then an ABY pedal is just what you need to switch between them. However, there's more to them than that!
So in this buyers guide, we shall explain exactly what ABY pedals are capable of. We'll provide advice on how to set them up, and also offer tips on how to use them effectively. Not only that, but we'll identify and compare some of the best examples available, with different price-points in mind to accommodate everyone.
ABY pedals have a very simple function, so if you have no idea about how they work or what they do, don't feel overwhelmed! An ABY pedal basically takes the lone signal from your instrument and splits it into two. Those two independent signals can then be sent to multiple amplifiers or sound sources, so you can switch between them for more tonal options.
For example, if you adore the clean sound of one of your amps but prefer the distortion from a different amp; this is where an ABY pedal becomes super-handy.
In case you were wondering, ABY isn't actually an abbreviation for anything; it's more of a visual clue. "A" and "B" represent the two amplifiers (or signals) that you intend to switch between or combine, simple. Whereas "Y" is indicative of the incoming signal entering the ABY pedal, with it then being split. Those signals then go into each of your amplifier inputs, with your sound projecting through their speakers.
As we have mentioned, an ABY lets you switch between amps for a wider range of tones. It therefore adds an element of versatility, as it gives you the choice between your favourite amplifiers. That may be enough to justify purchasing one, but some ABY boxes can offer far more tonal possibilities.
For example, more advanced ABY switchers also let you use two amps simultaneously and in conjunction with one another. Using multiple amps together can create a far richer tone, with more harmonic content and generally a bigger, more-engulfing sound. There are many high-profile names that use multiple amps for this purpose, such as John Mayer and Adam Jones (Tool).
Looking at the latter in particular, Adam Jones has maintained the same amp combination in his band for almost 20 years. His Diezel VH4 delivers all of the powerful high-gain he requires for his famously heavy riff-work. However, his old 1976 Marshall Super Bass provides plenty of vintage mid-range to give his sound more focus and punch. For him, it is clearly a winning combination! If you want to learn more about capturing his tones, check out our dedicated 'Sound Like Tool' blog.
Another reason why some players use two amps is so that they can form a stereo rig. Stereo is where you have two sound sources placed left and right. Our ears pick up sounds from all around us, and in music production you'll find that most recorded guitars are double-tracked and panned hard left and right. So to emulate that in a live situation, many players will use an ABY unit to run their amps together, with each on different sides of the stage or separated by some distance.
This just offers a larger, more three-dimensional vibe - and in most instances, it sounds incredible. Another big advantage of a stereo rig is to use stereo effects in conjunction with your amps. There are many modern pedals that have dual inputs/outputs marked "L" and "R", signifying left and right. You'll find these commonly on delay, reverb and modulation effects in particular. In stereo, they really enhance your overall sound!
For example, most multi-delay pedals like those offered by Strymon and Boss will have stereo integration. With multiple delay types such as "ping-pong" available, in a stereo setup the delay repeats will bounce between the speakers of each amp. This provides an amazing aural experience, and is used a lot by guitarists in the studio too.
Running two amps together may give you an awesome sound, but doing so can result in phase cancellation. This occurs when similar frequencies from separate sound sources are played together, which are exactly or partially opposite one another. This is also known as 180 or 90 degree phase cancellation respectively. The problem with cancellation is that it gives an unpredictable and inconsistent tone, essentially neutering your overall sound.
In context, think about it this way... If you're playing either a riff or a chord progression with an ABY unit splitting your signal into two, what you're playing is doubled and those frequencies will oscillate at the same speed. However, those frequencies will be slightly different, as they are emitted through different amps with their own unique tonal characteristics. Those simultaneous frequencies may then end up fighting one another if 180 or 90 degrees out-of-phase, which you certainly don't want! Sometimes this is worse with similar amp combinations, but it may not occur with a more diverse pairing.
If a power struggle materialises with the opposing frequencies cancelling each other out, you'll be left with a flat and thin sound. So to avoid this, many ABY boxes will feature a "polarity reversal" switch. What it does is quite obvious from its name. It will take one of the signals and reverse or invert it, so that the peaks of the second waveform will occur closely in unison with the other. That's science.
There are a number of brands that manufacture their own ABY boxes. The majority of these are in a pedal format with footswitches, and can be mounted easily onto your pedalboard so that you can switch between your amps on-the-fly.
Radial Engineering have a large range of high-quality ABY pedals, the majority of which feature that useful "polarity reversal" switch that we explained above. Many of their units are generally more specific and tailored towards tube or solid-state amplifiers.
The main perk of their ABY pedals is that they allow you to switch between your amps whilst using the same speaker cabinet, keeping them both loaded at all times in order to prevent damage. So if you don't want to run in stereo but want to switch between amps, this is a great solution. It also keeps your rig more portable and manageable!
If you'd prefer something a bit more substantial that keeps your tone at its optimum, Fulltone have some great ABY pedals. Built like tanks, these units are roadworthy boxes made to the highest standards.
With premium circuitry, these are regarded for their buffered bypass. Although some may prefer true bypass for keeping their sound as transparent as possible, this isn't always a good thing. For example, if you're running many metres of cable between your instrument and amp inputs with pedals in between, you'll lose heaps of clarity and top-end. However, using buffered pedals will prevent this. This is because a buffer transforms your signal into a stronger low impedance, restoring the fidelity and presence.
Fulltone's ABY pedals, as well as many of Radial's, will feature a "ground lift" switch. This is because when running two amps together, they can generate electrical noise and hiss, which is like kryptonite for guitarists. The ground lift is a function that can be used to combat this problem, eradicating the noise that can arise from ground loops in cables.
Another company renowned for its ABY units, also offering quiet operation, is Lehle. Hearkening from Germany and bringing all of the engineering prowess that they are renowned for, Lehle's ABY units are being used by some of the guitar world's most prestigious names.
Made with incredible attention-to-detail, Lehle units are intuitively designed and offer brilliant transparency, retaining the pure sound of your amps. This is thanks to their signature LTHZ transformer, which is "ideally suited to electrical isolation of the high impedance signals normal for electric guitar."
The brands that we've just highlighted offer amazing ABY units, which are made with premium components and attention-to-detail. However, if you're looking for a simple, no-frills ABY unit then there are also some great affordable options too!
Boss and Mooer make some basic, affordable ABY pedals that provide the essential functionality to switch between two sources. Both compact, these ABYs are easy to set up on your pedalboard so that you can start experimenting with your dual-amp rig.
Electro Harmonix and MXR also offer their own iterations, which are inexpensive and get the job done. These double-formatted pedals have a dedicated footswitch for flicking between amps, but also another switch to engage both. Featuring true hardwire bypass, these ensure quiet and pop-free operation.
From what we've explained, it's clear that there are a lot of potential options available. It's great that the price-range is so broad! If you're looking for a simple ABY on a budget then there are many contenders out there, but if you want a more robust and reliable ABY unit that keeps the noise down and retains the full tonal goodness of your amplifiers, then a more high-end option will suit your needs far better.
Essentially there's no right or wrong. Just determine exactly what you want before pulling the trigger on a purchase. And most importantly, do your research before you come to a decision. Many of the ABY units available to buy on our website have customer reviews, so it's worth checking those out to help choose the most ideal product for your setup too. Have fun finding the right one!
For more information about other relevant pedals, check out our dedicated guides:
