Mesa Boogie Rosette 300 / Two:Eight Acoustic Combo

Mesa Boogie Rosette 300 / Two:Eight Acoustic Guitar Amplifier Combo

Few can deny the intrinsic beauty of the Acoustic Instrument, especially the Acoustic Guitar. The visual beauty of the Tonewoods, the curvaceous shapes and elegant lines of body styles, and the delicate artwork of inlay all coalesce in harmonious interplay with tensioned strings to produce musical promise.

So when MESA® turned their eyes and ears toward amplifying these sounds, one thing more than any other stood out as an objective; Do No Harm. In its sincerity and perfection, there is no reason to “enhance” the sound of the acoustic guitar, or any other acoustic instrument for that matter, but rather… just reproduce it.

Unlike electric guitar amplifiers that offer myriad enhancements and often complete re-voicings, the acoustic instrument has all the complex harmonic content it could ever need, on-board. All that is required is the accurate reproduction of that beauty.

While staying true to the concept of Do No Harm, few products or companies seem to share this perspective for Acoustic Amplification. And when it comes to the electronic and mechanical components and design needed to fulfill that order, it’s easier said than done. It requires a commitment to using the absolute best components and circuit design dedicated to uncompromising accuracy, purity of sound and the lowest possible extraneous noise.

The ROSETTE line is a dedicated acoustic instrument platform designed not just for acoustic guitars, but also for mandolin, ukulele, violin/fiddle, dulcimer, cello, upright bass and other uniquely acoustic instruments.

Mesa's reverence and appreciation for acoustic instruments guides the designs of the Rosette Series products. Their commitment to produce innovative, reliable and inspiring musical instrument amplification for nearly 50 years, finally includes the incredible world of acoustic instruments.

OVERVIEW: FRONT PANEL

In Rosette, they opted for architecture straight from high-end recording console designs. They developed Input stages that were not the typical, compromised dual-purpose circuits fed by universal XLR+1/4” combo jacks found on many acoustic amplifiers in the marketplace. Instead, they chose dedicated, time-tested designs, proven over decades of great recordings, to deliver the uncompromised, accurate truth.

In the MIC Input of Channel 1, a rugged, professional XLR jack uses a dual discrete transistor pair for the trans-conductance Input stage. Because microphones are low impedance transducers, the noise current specification must be at the top of the design list for the best noise performance and Tone.

Rosette Inputs
Professional features include optimized channel specific XLR and ¼” inputs. Optimized input circuitry addresses common tone degradation issues associated with compromised dual-purpose circuits fed by universal combo jacks, standard on many acoustic amplifiers today

Channels 1 and 2 feature duplicate ¼” mono PICKUP Inputs with input stage circuitry optimized for the impedance requirements of today’s (and yesterday’s) popular acoustic guitar pickups. A current source biased FET input stage was selected for this application as high impedance transducers require the noise voltage specification be the first consideration for optimal performance and Tone.

This purpose-built, no-compromise approach to the connection of your instrument pickup to the Input stage of the amp clearly states Mesa's mission with the Rosette Series. While it may look different from the crowded field of less sophisticated offerings in the marketplace, it is by far the proper and professional way to get the absolute best from the all-important instrument/pickup/amp input connection. Tone begins, and can end, at the Input Stage.

MUTE and PHASE switches accompany each channel’s Input features. Channel 1’s Input options are selected by the MIC/LINE switch, which determines the Input architecture.

LEDs provide clear indication of the status of MUTE and PHASE selections. A RED pair indicates Channel MUTE, while an additional RED LED below the MIC Input indicates the default Phantom Power ON status (harmless to non-phantom-powered mics). The BLUE LEDs being ON indicate the Phase being 180 Degrees flipped in relation to the INPUT signal.

Rosette Parametric EQ
4-Band EQ Section provides the same degree of shaping power found in upscale recording or live sound consoles. Separate LOW and HIGH semi-parametric MID Bands allow specific control over a wide range of frequencies.

Next up on the Front Panel are the GAIN and FX SEND level controls. GAIN adjusts the input gain level for each channel and the FX SEND determines the amount of that signal to be routed to the internal Effects Processor or the SEND of the EXTERNAL EFFECTS LOOP.

The HI-PASS Filter can reduce or eliminate low-end feedback and tone issues before they can arise or be exacerbated with unintentional overuse of the EQ section. HI-PASS allows you to dial out the over-resonant, tubby frequencies that often create unwanted feedback, especially in bigger, more resonant guitars and acoustic instruments.

The fully professional 4-Band EQ Section provides the same degree of shaping power found in upscale recording or live sound consoles and together with the optimized INPUT circuitry, creates two impressive Channel Strips for amplifying acoustic instruments. The separate LOW and HIGH semi-parametric MID Bands allow specific control over a wide range of frequencies and can easily overlap if needed. This professional level Tone and Frequency control places the Rosette in a category beyond standard acoustic amps and in with the best of high-end Pro Audio gear.

Rosette FX
On-board Effects Suite includes three effects choices: ROOM REVERB, HALL REVERB and REVERB AND CHORUS. PARAMETER Controls provide unique adjustment of specific effect functions in each of the three modes.

Mini LED Indicators in the upper right corner of the Front Panel alert you to: 1) clipping the power section and the LIMIT circuit is being activated (YELLOW). 2) the amp overheating due to excessive Output or settings for prolonged periods (RED). 3) the amp’s Pilot light indicating the AC MAINS Power has been switched on (BLUE).

The on-board Effects Suite includes three effects choices: ROOM REVERB, HALL REVERB and REVERB AND CHORUS. These effects programs create many ways to add spatial enhancement to the sound of your instrument while the PARAMETER Controls provide unique adjustment of specific effect functions in each of the three modes. The FX MASTER control determines the overall mix of the effects to the dry signal to achieve the desired dry/wet blend.

Finally, The MASTER control at the far right bottom of the Front Panel provides volume adjustment of the amplifier and controls the overall output from the 300 watt power section that drives the Rosette’s two 8” custom neodymium speakers.

REAR PANEL

From Left you can first see the AC MAINS power switch and the industry standard IEC AC MAINS removable Power Cord Socket. Never Alter the Power Cord in any way to reduce the risk of electrical shock. Be sure the Power Cable is seated firmly and completely in its receptacle.

The Rosette 2x8 Combo utilizes a single SPEAKER OUTPUT to ensure the maximum 300 watt output power is provided via the optimized internal 4 Ohm speaker load..

Rosette Rear Jacks
HEADPHONE Output is provided for personal monitoring, with or without the combo speakers connected. A Channel MUTE FTSW Jack allows remote control muting of the Channels and Full FX LOOP and BYPASS add to a full suite of pro features.

A HEADPHONE Output is provided for personal monitoring, with or without the combo speakers connected. If you wish to play with headphones ONLY (not using the Rosette’s internal speakers), simply unplug the Speaker Cord from the SPEAKER OUTPUT jack. Operating the Rosette’s Class D amplifier without