Original version of the BigShot ABY
BigShot ABY inside view
BigShot i/o, EFX, & ABY

BigShot ABY™ Development

When we set out to build the original BigShot ABY, we had several goals in mind: For tone aficionados it had to be true-bypass. To fit on a pedalboard it had to be compact. To be useful for touring it had to be rugged and it had to be plug & play easy to use. The ABY is a simple switcher that allows you to toggle the signal between two amplifiers whereby one could be a Fender Twin® set to deliver a clean tone while the other could be a Marshall® for crunch or distortion. When developing this latest generation, we wanted to retain these features while adding LED indicators to improve the on-stage performance.

True-Bypass AB performance

The never ending quest for great guitar tone drives 'the purist' to extremes. For many, this comes down to committing to a 100% true-bypass signal path. In other words, they do not want anything in between their guitar and the amp that could mess up their tone other than a high quality guitar cable.

The BigShot ABY is exactly that. A true-bypass ABY switcher that was designed from the ground up to be simple, have the least amount of circuitry possible and most importantly, it had to provide simple mechanical switching so that the purist could get the tone he craves. You simply hit the AB switch to toggle between amps.

Dealing with the Y in ABY

A second switch was added to our switcher that enables both amps to be played at once. This could for instance be used to combine the attack of a clean tone with the distortion of another for added definition. But playing two amps at once is not always as simple as it seems. Hum and buzz caused by ground loops is one of the most common problems. This is caused by differing electrical voltages known as DC offsets from each amp interacting, which in turn causes noise.

The BigShot ABY presents two remedies: A ground lift switch disconnects the audio ground going to the second amp which can often help. The other option is to insert an isolation transformer into the signal path. This disconnects the hard electrical connection by introducing a magnetic bridge. A transformer is a passive device like a magnetic guitar pickup. It blocks stray DC voltage which is a primary cause for so-called ground loops. Unless buffered by another pedal, when a transformer is inserted into the signal path a transformer will cause a slight tonal change which means you will have to compensate on your amp. But this is a small price to pay versus playing with horrendous hum in your amps that may make them completely unusable.

Playing in phase

Another issue when playing two amps at once is making sure they are in absolute phase. This may seem odd, but many amplifiers and guitar pedals will often reverse the polarity of the signal. In pro-audio, this is very important as stereo signals are common. With guitars, only a select few have their rigs set up in stereo. So if the two amps are out of phase, when played together, they sound distant and lack punch.

The BigShot ABY ads yet another control that enables you to switch the polarity by 180 degrees... or bring the two amps back in phase. To test, simply point your two amps towards each other and turn them both on and toggle the polarity switch from one position to the other. If the bass cancels out, you are out of phase.

Turning on the lights

The single most common request we have received over the years was to add LED indicators on the ABY to enable the user to quickly monitor the signal status. This allows the user to pick up his guitar, look down and know exactly what amp will be active without having to pre-test. This can also prove to be essential for multi-instrumentalists that may jump from one instrument to another and lose track of their settings.

Although this may seem simple, adding a bunch of electronics and relays to turn on LEDs without affecting the signal path is not as simple as one may think. After much deliberation, we instead chose to source a special 9 pole switch that would allow us to retain the true-bypass performance, yet allow the LEDs to be illuminated using the spare contacts. Adding features adds cost. So instead of incorporating a battery compartment, we decided to keep things simple and only have the LEDs work when connecting to a power supply as most players today employ pedalboards that are equipped with power bricks.

Adding extra facilities

At Radial, we are often accused of over-building our products and loading them with too many options. The metal shop will often suggest thinner metal to save money. Some techs will say our products have too many features that can confuse some musicians.

Yes, we are absolutely guilty as charged... but in our view, these extras can often be very helpful in certain situations. For instance; in the BigShot ABY we chose to add a separate tuner out. This is particularly useful for tone craving guitarists as tuners generally buffer the signal which alters the true guitar tone. By taking the tuner out of the primary signal path, you get to keep your tone and tuner too...

The argument for an active ABY

Radial makes a variety of ABY switchers to suit every player. The BigShot ABY is a simple true-bypass device that is now equipped with LED indicators. For those that want quieter performance and active buffering, the TwinCity™ and Switchbone V2™ offer more features and several innovative solutions.

The Radial BigShot ABY answers the need for a compact, simple and effective amp switcher with 'straight wire' true-bypass connectivity for the purist, with the option to switch a noise eliminating transformer into the circuit should ground loop induced hum and buzz be a problem.