Hello,

  This is from the Pilots Guide of the amp:

  Channel Memories -   Four programmable channels come pre loaded

  with great factory presets. To save a preset hold any A, B, C, or D

  button for two seconds.

  http://l6c.scdn.line6.net/data/l/0a06007215eae4a857e7d206c4/application/pdf/Spider%20IV%2030%20Pilot's%20Guide%20(Rev%20E)%20-%20English.pdf

  Line6Miller