The Mesa Boogie .50 Caliber+ has always lived in the shadow of the Mark series, which is a shame because these amps are absolute monsters.

Built in the late 1980s and early 1990s, the .50 Caliber+ packs 50 all-tube watts through a pair of 6L6 power tubes. And before anyone says, "It's only 50 watts," let me assure you that Mesa apparently measures wattage differently than the rest of the world. This amp is LOUD.

This is the original combo version and still carries its original speaker, giving you the complete Mesa package the way it left the factory. Cosmetically, this amp has aged as gracefully as its tone. The tolex and grill cloth are both in excellent condition, making for a vintage Mesa that looks every bit as good as it sounds.

The clean channel has tremendous headroom and can stay sparkling clean at volumes where many amps are already waving a white flag. Push it a little harder, though, and it starts to break up with a beautiful vintage-Fender-like growl that blues and classic rock players love.

Step over to the lead channel and the personality changes completely. Thick, saturated Mesa gain is on tap, with enough sustain to make you forget where the note started. The gain structure is a little different from the Mark series, with the tone controls placed after the gain stages, resulting in an amp that stays tight and focused while delivering plenty of punch.

One of the best features is Mesa's legendary 5-band graphic EQ. You can use it to sculpt your lead sound, kick in a solo boost, or dial in that classic "V" curve that helped define an entire generation of rock guitar.

Features include:

• 50 watts of all-tube power
• Original combo cabinet with original speaker
• 2 x 6L6 power tubes
• 5 x 12AX7 preamp tubes
• Two footswitchable channels
• Mesa 5-band graphic EQ
• Built-in spring reverb
• Effects loop

This amp has been thoroughly played through and tested here in our shop and has earned the coveted Wendell Walker Seal of Approval.

The .50 Caliber+ may be the best Mesa nobody talks about until they actually play one.

If you've been looking for a hand-built American tube amp with classic Mesa attitude, this one deserves a serious look.