Best Recording Signal A-B Boxes AI pick
Chosen by an AI model from its trained knowledge, with its reasoning.
AI pick: Radial BigShot ABY
A passive true-bypass box that switches one guitar between two amps or runs both at once, with an isolation transformer on one output to break ground-loop hum when you use both amps.
Not for: Anyone who needs to switch amp heads, synth line outputs or more than two destinations.
AI picks by need
For switching one amp head between two speaker cabinets
Radial Headbone (line)
Built to switch amplifier heads and cabinets at speaker level, which ordinary instrument ABY boxes cannot do safely.
Not for: Anyone switching instrument or line-level signals.
What the AI looks for in Recording Signal A-B Boxes
- Signal level
- Instrument ABY boxes handle instrument-level signals only. Never put speaker-level amp outputs through them. Speaker-level signals can damage a box that is not designed for them, and they can damage the amp too.
- Ground isolation
- Choose a box with a transformer-isolated output or a ground lift if both outputs will be active at the same time. Two amps on different grounds almost always hum when they are fed together.
- Phase/polarity switch
- For 'both' mode, choose a box with a polarity-reverse switch on one output. Two amps out of phase sound thin and lose low end, and you need to be able to fix that.
- Passive vs buffered
- Use passive for short cable runs. Add a buffer if the total cable length is long or if the box feeds several amps. Long cable runs and split loads dull the high end of passive pickups.
Brands that matter
- Radial: The widest range of ABY, A/B and amp-switching boxes, built for touring.
- Lehle: Premium German switchers known for quiet, transparent switching.
- Morley: Simple, affordable pedal-style ABY selectors.
What to avoid
- Unbranded switch boxes with no ground lift, used in dual-amp setups
- Instrument ABY boxes used to switch speaker cabinets
Questions
What is the difference between A/B and ABY?
An A/B box picks one output or the other. An ABY box can also feed both outputs at once.