Mesa/Boogie (also known as Mesa Engineering) is a company in Petaluma, California that makes amplifiers for guitars and basses. It has been in operation since 1969.

Mesa was started by Randall Smith as a small repair shop which modified Fender combos to give them more gain. Prominent early buyers included Carlos Santana and Keith Richards of The Rolling Stones, helping to develop Mesa/Boogie’s reputation as a major high-end amp builder.
The Rectifier series, commonly called “Recto” by modeling amplifiers, was instrumental to the success of detuned 7-string nu- and heavy-metal in the 90’s. There are 4 variants: Single, Dual and Triple Rectifier. There were also Tremoverb and Rectoverb models.

The Single Rectifier amplifiers are rated at 50 watts and use a silicon diode rectifier, as opposed to tube rectification. Currently in production are the Single Rectifier Solo Head 50, the Rect-o-Verb 50 head, and the Rect-o-Verb 50 combo, which is fitted with a single 12″ Celestion Black Shadow speaker.