The Rectifier Recording Preamp is a guitar preamplifier that emulates a combination of a Mesa/Boogie Dual Recitifer amp head and a 4x12 Rectifier speaker cabinet.

Mesa/Boogie's new Rectifier Recording Preamp is an all-tube (six 12AX7A dual-triode) DI recording solution for electric guitar, designed to emulate the sound of the company's Dual Rectifier Solo Head blowing through a 4×12 Rectifier cabinet. Although the “Recto” is first and foremost a direct-recording device, the 2U rackmountable unit also provides outputs to feed your guitar amp.


Most of the Recto's action takes place on its front panel, where you'll find an unbalanced, transformerless instrument input and control knobs for two discrete channels (see Fig. 1). You can sculpt a clean tone suitable for chording on channel 1, for example, and a more aggressive timbre for soloing on channel 2, which offers hotter gain. Then you can switch back and forth between the two channels and sounds by manually flipping a front-panel switch or by stomping on the supplied footswitch's Channel button. A green or red LED lights to alert you that channel 1 or channel 2 is selected, respectively.

Each channel is served by a three-way Mode switch that gives you a starting point for fashioning your guitar tone. Channel 1 modes are labeled Clean, Fat, and Brit, while channel 2 modes are called Raw, Vintage, and Modern. The two channels each provide a row of gain- and tone-control knobs that further sculpt your timbre. Those knobs span the left and center portions of the faceplate and are labeled Gain, Treble, Mid, Bass, Presence, and Master. The Master control sets the relative volume of each channel, allowing you to set solo levels hotter than chording levels, for example. That scheme also lets you crank any channel's Gain knob to get more tube saturation without committing to higher-volume output.

You can further modify channel 1 tones by kicking in the Bright switch or -3 dB pad (which have no effect on channel 2). Activating the Bright switch boosts the highs above the band affected by the Presence control; it's mostly useful for recording applications, as it provides a little sparkle and air that you probably wouldn't notice when playing through a cabinet in a nightclub. The -3 dB switch (which pads the grid of the input tube) works best in situations where a cleaner tone is desired.

The Rectifier provides separate stereo pairs of balanced outputs (dubbed Record Out and Live Out) on its rear panel for direct-recording and externally amplified applications, respectively. You control their levels with two ganged-element potentiometer knobs (that is, one knob adjusts left and right levels equally for a given output) on the front panel. A third knob, labeled Live-Solo, provides an additional boost to the active channel at the Live Outs when you select the Solo function on the Recto's footswitch.

The Rectifier's sturdy, compact footswitch features LEDs that show the status of its Solo and Channel buttons — the only controls the footswitch offers. The footswitch connects to a front-panel jack on the Recto by way of a supplied cable that measures roughly five meters long and is fitted on both ends with ¼-inch TRS plugs.

Also on the Rectifier's front panel are a large, red power-status lamp and power and standby switches. Powering up in standby mode will extend the life of the Recto's tubes.


As mentioned earlier, the Rectifier provides separate left and right Record and Live outputs on its rear panel (see Fig. 2). The outputs are all on balanced TRS jacks but will accommodate unbalanced lines as well. The frequency responses of lead-guitar (channel 2) tones from those two pairs of jacks are simultaneously affected by a front-panel switch that toggles between Live Bright and Warm Record settings. (The Live Bright/Warm Record switch has no effect on output signals derived from channel 1, however.) As you would expect, the Live Bright setting produces a brighter timbre most suited for playing through a guitar amp and cabinet, whereas the Warm Record setting produces a less edgy tone that's best used for routing directly to a recording console.

The Live Bright/Warm Record switch setting affects both the Record and Live outputs simultaneously, so the sound at one pair of outputs will always be inherently different. If you want to record direct and with a mic on your cabinet at the same time, you can choose the Warm Record setting and boost the treble band at your guitar amp to brighten your cab's sound.

An effects loop is located on the Rectifier's rear panel. The effects loop comprises a single send and separate left and right returns on electronically balanced TRS jacks and a wet/dry FX Mix rotary control. The loop is placed in the audio path just before the Record and Live outputs. For the highest fidelity, though, you'll want to forgo the effects loop and patch outboard gear in to your signal chain somewhere downstream from the Recto's Record or Live outputs.

The Rectifier's rear panel provides two additional ¼-inch jacks; one is an input for an external device to switch the unit's two channels, and the other activates the Solo function. The owner's manual is vague about how these jacks work except to say that any MIDI switcher that uses “tip-to-ground, latching type logic” (such as the Digital Music Corporation Ground Control) will do the job.

Yet another ¼-inch jack (labeled Modern) provides an external trigger for Mesa/Boogie's Rectifier Stereo 2:100 power amp. The Rectifier's manual states that this jack accepts an “unshielded cable and any tip-to-ground latch type switching logic.” When you patch this jack to the 2:100, the Recto's footswitch Solo button becomes a toggle for switching between channel 2's Modern and Vintage modes in live applications. With this setup, the channel 2 Master knob controls the level for Modern mode, and the Solo knob controls the level for Vintage mode. Because the footswitch's Channel button still toggles between channels 1 and 2, you gain footswitch access to three different modes (Channel 1, Modern, and Vintage) when you patch the Recto's Modern trigger jack to a 2:100 amp.

Also on the Rectifier's rear panel are a redundant instrument input, a ground-lift switch, and an IEC receptacle that accepts the supplied detachable AC cord.


I first tested the Rectifier Recording Preamp with my '62 Fender Strat, patching the Recto's Record Outs to my Yamaha 02RV2's A/D converters. The Recto's wide-ranging controls make it easy to set optimal levels and attain a variety of guitar tones. The Recto can deliver everything from jazz to blues to hard-rock timbres. The Record Out control offers enough gain to easily attain 0 dBfs levels at the 02RV2's insert-return jacks. The Gain and Record Out controls can attenuate down to minus infinity (no sound). Unfortunately, it is very difficult to ascertain the position of any of the Recto's chrome knobs at an angle or in low light, as the hash marks on the knobs are not colored.

In a session with Portland, Oregon-based jazz guitarist Andy Guzie, the Rectifier's clean (channel 1) tones lacked the pristine sparkle and depth we were shooting for. Channel 1 delivers tones that sound very similar to what a high-quality live rig puts out when its tubes are driven lightly. If you're looking for a good emulation of a clean guitar tone produced by an amp cab — that is, a sound with a little bit of grit and slightly muted highs — you'll probably love the Recto's channel 1 tones.

The Rectifier's channel 2 sounds great. Crank its gain to the max and the Recto rocks hard, dishing out plenty of smooth, warm sustain. With the Presence control set to about the 10 o'clock position (in Modern mode, with all other tone controls set to about the 1 o'clock position), the Recto lent my vintage Strat a warm, “brown” tone (borrowing from Eddie Van Halen's lexicon) that made me want to play for hours. And as every guitarist knows, a smooth, sustained tone can psychologically make your guitar strings feel silkier and help you play better. The Rectifier's smooth saturation characteristics are arguably the unit's greatest attributes.


Because the Rectifier's owner's manual was written from a musician's perspective, recording engineers will find that it lacks important documentation. Electronic specifications are almost totally absent.

The unit is less versatile than some competing products that cost less and also offer effects and compression. That said, the Recto's value lies in its uncanny ability to reproduce the authentic timbres of a tube-based guitar amp in a direct-recording environment. If that's the sound you want, the Rectifier Recording Preamp delivers in spades.

EMcontributing editorMichael Cooperis the owner of Michael Cooper Recording, located in beautiful Sisters, Oregon.


Rectifier Recording Preamp
guitar preamplifier


PROS: Authentic, smooth tube timbres. Wide-ranging gain and tone controls. Two discrete channels. Separate pairs of outputs allow simultaneously recording direct and playing live through an amp and cabinet. Rugged construction. Supplied footswitch.

CONS: Knob positions are very difficult to see. Frequency response can be optimized for direct recording or externally amplified applications, but not for both simultaneously. Loading the unbuffered Live Outs causes a significant drop in signal level at the Record Outs. Spotty documentation. Relatively pricey.


tel. (707) 778-6565

Rectifier Recording Preamp Specifications

Inputs(2) unbalanced ¼" TS, high impedance; (2) balanced ¼" TRS (effects returns)Outputs(2) balanced ¼" TRS (Record Outs); (2) balanced ¼" TRS (Live Outs); (1) balanced ¼" TRS (effects send)Switch Inputs(1) ¼" TRS; (3) ¼" TSPower Supplyinternal; IEC connectorDimensions2U × 12" (D)Weight16 lb.