The Radial BigShot ABY is a compact true-bypass ABY switcher from Radial Engineering that lets you switch between two amplifiers or play through both at the same time. Two latching footswitches choose which amp is active, or run both simultaneously, and Radial notes that with both amps on at once "it creates a wall of sound that immerses you into the music and elevates your creative spirit"1. The audio path is 100% passive and does not require power2.
What sets it apart from a simple Y-cable is noise control. The second amp output (Output-B) has a ground lift and a switchable isolation transformer that can be engaged to eliminate buzz and hum from ground loops, a common problem when two amps share one guitar2. Radial describes it as a true-bypass device "without any tone-altering buffers between the guitar and the amplifier"2.
The controls and jacks
The front panel is built around two latching footswitches and a small set of switches and jacks. Radial's feature page breaks down each element5:
| Control or jack | What it does |
|---|---|
| Input jack | Standard 1/4" jack connects the instrument to the ABY5 |
| Output-A | 1/4" jack, one of the two amp outputs53 |
| Output-B | 1/4" jack that connects to your main amp, with ground lift and switchable isolation transformer25 |
| Tuner out | Separate 1/4" output for your guitar tuner, always on5 |
| A-B footswitch | Selects which amp is active2 |
| Both footswitch | Turns both outputs A and B on at the same time5 |
| ISO switch | Engages the isolation transformer; ON (up) puts it in the circuit4 |
| POL switch | Reverses polarity 180 degrees4 |
| Lift switch | Disconnects the ground from the cable shield on output B5 |
| A-B LED | High-visibility indicators show which output is active (power required)5 |
| Both LED | Shows when both amplifier outputs are active (power required)5 |
The ISO, POL and Lift switches work together as a noise toolkit. Radial's guidance for tackling hum is to first engage the ISO switch to the ON (up) position, then engage the POL switch to the 180º (up) position4. The isolation transformer uses custom Radial transformers for what the maker describes as distortion-free signal transfer and 100% isolation from ground loop hum5.
The tuner out is worth a note: Radial calls it an "always on" output that feeds the tuner for constant monitoring while keeping "this tone altering device out of the main signal path"21. Because it is always active, it cannot be switched off from the BigShot itself4.
The tuner out can also run a third amp, but since it is always on you cannot mute it from the BigShot. Radial advises that when running a third amp you "ensure that you power all of your amps on one electrical circuit to avoid nasty ground loops"4.
Power: optional 9V for the LEDs
The BigShot ABY does not need power to switch your amps. The audio path is fully passive2. Power exists only for the LED indicators: "You can operate the new BigShot ABY with or without a 9V Boss-Style adapter, the power is only used to illuminate the LEDs"4. When powered by an external 9V supply or pedalboard power brick, the LEDs provide instant on-stage visual feedback2.
The power connection accepts 9 to 12 volt DC with a center pin negative5, and the spec sheet lists 9VDC, center pole negative3. There is no battery compartment: Radial says it wanted the BigShot ABY to be easy to use, compact and affordable, and that most players who need the LEDs to manage their amps already use a power supply4.
The BigShot ABY is not designed to handle speaker-level signals and cannot switch amps or cabinets at speaker level4. It belongs between your guitar and your amps' inputs, not in a speaker cable run.
History and versions
The BigShot ABY has been through a few iterations. Radial Engineering announced the Tonebone BigShot ABY rev 2, an updated version of its guitar amp switcher1. Guitar Interactive Magazine reported the same launch, describing the rev 2 as "completely passive meaning that there are no tone altering buffers in between the guitar and the amplifier"6. According to Radial, the only differences between the original legacy version and the new BigShot ABY are aesthetics and the addition of the LE4.
Radial's support pages distinguish between the original (legacy version) and the new BigShot ABY, saying the only differences are aesthetics and the addition of the LEDs4. The current product page lists it simply as the BigShot ABY, part number R800 7210 002.
Build and specifications
Radial builds the BigShot ABY into a 14-gauge steel enclosure, which the maker says prevents the circuit board from being torqued in a way that could lead to part failure, with a durable powder coat finish53. Inside, the mil-spec PCB has a full ground plane for noise-free performance and double-sided through-hole solder points for durability5. The footswitches have metal outer casings rated at over 20,000 cycles5, and the connectors sit in glass filled nylon housings that Radial describes as tougher than steel, providing isolation for reduced noise, with nickel silver contacts that will not tarnish5.
| Specification | Value |
|---|---|
| Audio circuit type | Passive, true bypass3 |
| Input connectors | 1/4"3 |
| Output connectors | Two 1/4" outputs, switchable transformer isolated from Output-B3 |
| Extras | Tuner output, ISO switch3 |
| Features | 180° polarity reverse, ground lift3 |
| Gain | -0.3 dB3 |
| Power | 9VDC, center pole negative3 |
| Finish | Durable powder coat3 |
| Conditions | For use in dry locations only, between 5°C and 40°C3 |
How it fits with Radial's other switchers
The BigShot ABY sits at the simple, passive end of Radial's switching range. Radial also makes the Twin-City and the Tonebone JX-2 Pro Switchbone for players who want more, and the BigShot I/O instrument selector for choosing between guitars rather than amps. For an overview of the category, see switching pedals.
Videos
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Pickin' On Brandon
Landon Bailey
Questions
Does the Radial BigShot ABY need power?
No. The audio path is 100% passive and works with nothing connected. Power from a 9V supply or pedalboard brick is used only to light the LED indicators that show which output is active. You can run it with or without power and it switches amps either way.
Does the BigShot ABY take a battery?
No. Radial says it left the battery out to keep the BigShot ABY easy to use, compact and affordable, since most players who want the LEDs use a pedalboard power supply anyway. Without power the pedal still passes and switches signal, just without the indicator lights.
Can the BigShot ABY switch speaker cabinets?
No. The BigShot ABY is not designed to handle speaker-level signals and cannot switch amps or cabinets at speaker level. It is an instrument-level device that sits between your guitar and your amplifiers' inputs, not a speaker cable switcher.
Can the tuner output on the BigShot ABY run a third amp?
Yes. Radial confirms the tuner output can feed a third amp, but it is always active and cannot be turned off from the BigShot itself. When running a third amp, Radial advises powering all amps from one electrical circuit to avoid ground loops.
Is the Radial BigShot ABY true bypass?
Yes. Radial describes it as a true-bypass device with no tone-altering buffers between the guitar and the amplifier. The audio path is completely passive, and the spec sheet lists the audio circuit type as passive, true bypass.
Sources (6)
- Radial Engineering Introduces the Tonebone BigShot ABY, Premier Guitar, 2016-07-11
- BigShot ABY, Radial Engineering, 2026-04-07
- BigShot ABY Specifications, Radial Engineering, 2018-04-10
- BigShot ABY FAQ, Radial Engineering, 2024-07-19
- BigShot ABY Features, Radial Engineering, 2022-07-12
- Radial Introduces Updated Tonebone BigShot ABY, Guitar Interactive Magazine, 2016-07-11
Jack White
