Up for sale, a 1990s Mesa Boogie Mark IV Revision A head in excellent condition and in perfect working order, complete with its multi-button footswitch and paired with a custom ported 1x12 speaker cabinet. Handcrafted in Petaluma, CA, from 1991-94, the Mark IV Rev A was easily one of the most sonically flexible and feature-rich tube amps on the market at the time of its production, still considered a high water mark among Mesa Boogie fans and tone tweakers alike. It has a huge array of tonal sculpting controls, with a footswitchable three-channel design, spring reverb, and a very efficient 85 watt output, channeled through an Electro Voice SRO 12” speaker.
The three channels all have distinct tones: the Rhythm 1 channel feels bouncy and pristine with a sparkling cut, the multi-stage “Cascading Gain” Lead channel is all blistering high gain focus and bite, and the Rhythm 2 channel offers a perfect middle ground between these two extremes. Regardless of which channel is engaged, the sheer scope of the tonal sculpting controls and five-band graphic EQ mean that the perfect tone for any stage or studio setting can be dialed in. Some unique features of note include the Silent Recording pull/push control, which mutes the signal at the power section; the push/pull Presence controls, which allow harmonic sizzle and edge to be adjusted; the Pull Fat and Pull Bright switches, offering midrange punch and additional high treble detail, respectively; and the two-way Full Power/Tweed Power switch, which works like a built-in Variac and lowers the power to create a spongier vintage feel.
The tube complement consists of a matched quad of Mesa 6L6 power tubes with a preamp section of three Mesa 12AX7s and two Mesa 12AT7s. The Mark IV Rev A can also operate with EL34s or 6V6s tubes. The Simul-Class power section essentially functions as two different power amps working simultaneously; one extracts Class A sweetness, while the other delivers the high-power punch of Pentode Class A/B. The Simul-Class can also be toggled to straight Class A. Other features include a Slave Out with Level control, Output Level control over all Channels, Pentode/Triode Switch, Record Out with a Level control, fan cooling, and lush onboard spring reverb.
The 1x12” closed back, ported cabinet is loaded with an Electro Voice SRO 12L speaker, rated at 8 ohms and 200 watts, with ceramic magnet construction. This speaker is extremely efficient and bold, with a focused, punchy low end, and immediate, hyper clear trebles.
Cosmetic touches on the amp head include a Boogie badge, black grillcloth, and silver corners. The custom-made speaker cabinet is similarly appointed, and both the head and cabinet are in fantastic shape, with cosmetic wear limited to a scant few tiny marks and scuffs on the enclosures as a whole. All of the original knobs are present, and the original graphics are pristine.
The original control diagram is included, specifically enumerating the vast array of controls and sitting helpfully atop the amp. The original six-button footswitch is also included, enabling on-the-fly toggling of the three channels, Lead EQ, graphic EQ, and Loops.