Alesis 4 Reference Manual page 27

Chapter 2 – Connections
Any momentary single-pole/single-throw footswitch, normally open or normally
closed, will work for the three footswitch functions. This should be plugged in prior
to power-up so that the MidiVerb 4 can configure itself for the type of footswitch
being used.
Advance. When the footswitch mode is set to the Advance function, each time the
footswitch is pressed the MidiVerb 4 will advance to the next Program number.
Bypass. When set to the Bypass function, pressing the footswitch will toggle Bypass
mode on and off (when Bypass mode is activated, the [BYPASS] LED will be lit).
Control. When using a Delay effect, the footswitch can serve as a way of
programming the delay time using a feature called "tap tempo". If the footswitch
function is set to the Control function, you can program the delay time in two ways:
• Press down on the footswitch repeatedly at the desired tempo you wish the
delay time to follow; or,
• Hold down the footswitch and the MidiVerb 4 will "listen" to the audio being
fed to its input(s); now you can play your guitar, bang your drum, or sing some
"doot doots" into your microphone (depending on what is plugged into the
inputs), and the delay time will be set to a value that equals the tempo you are
using.
When the Footswitch parameter is set to the Control function and the Lezlie->Room
Configuration is being used, pressing down on the footswitch will toggle the Speed
parameter in the Lezlie effect between its slow and fast settings.
For more information about tap tempo, see Chapter 3.
26 MidiVerb 4 Reference Manual