Up for sale, a 1989 Mesa Boogie .50 Caliber+ 1x12” combo amplifier in excellent condition and in perfect working order. This classic Mesa amp is a fantastically versatile combo with the classic compact Boogie-size footprint, delivering a huge array of tonalities, a mainstay of countless studios and on stages since its introduction in ‘88 (discontinued ‘93) thanks to its reliability and premium sound.

A dual-channel, single-input design, this Plus version of the .50 Cal features a pair of 6L6 power tubes, with a power rating of 50 watts, and this combo throws a surprising amount of sound, but can easily be reigned in for lower volume applications without losing any of the robust, full-bodied tone. A big part of that ability stems from the five-band graphic EQ, and the Gain knob contains a push/pull control to toggle between the Clean and Lead (High Gain) channels, with extremely different tonal profiles between the robust, natural warmth of the former and the higher gain crunch of the latter. The channel switch is also footswitchable for on-the-fly rhythm to solo transitions while playing, and the spring reverb is lush and splashy.

This combo is loaded with a matched pair of Mesa’s own 6L6GC power tubes, with four 12AX7 valves in the preamp. The output transformer dates to the 41st week of 1989, and this .50 Cal+ has been upgraded with a Mercury Magnetics Axiom power transformer. Originally sold within the Japanese market (with a corresponding 100v power transformer), this Mesa has now been fully serviced for use in the USA. This amp is loaded with a Celestion Black Shadow Custom 90 12” speaker, produced exclusively for Mesa with tight, controlled lows, plenty of low-mid authority, and an assertive-yet-composed top end, perfect for cutting through a mix without any harshness while retaining excellent headroom.

The cabinet is crafted from marine-grade Baltic birch, and cosmetic touches include Black Bronco tolex, black grillcloth, and a MESA/Boogie badge. There are a few minor tears on the tolex, the graphics are very clean, and all of the original knobs are present.