This morning I came across an interesting function/utility pedal called the George Lynch Morley Tripler, which is a A/B/Y splitter. You can have a single input go to three outputs. Additionally, there is a 20dB input signal boost. Unit has LEDs that indicate what outputs are activated and is housed in a rugged enclosure.
The concept of the Tripler is to allow you to run your signal to three amps. This is switching on the input of your amp, not a head switcher – important difference. With the Tripler, you can have individual amps running or a combination of amps going.