guitarrón

(from the article `mariachi`) ...mariachi include the vihuela, a type of guitar having six double courses of strings, popular in the Spanish Renaissance; the guitarrón, a large, ...
Found on http://www.britannica.com/eb/a-z/g/81

Guitarron

Large bass guitar of Chile and Mexico. The Mexican version is a 6 string Mariachi bass guitar, while the Chilean is a 26 string troubadour's instrument related to the Cuatro.
Found on http://www.hobgoblin-usa.com/info/glossary.htm
No exact match found