ROSETTE® 300

ACCURACY FIRST, EMBELLISHMENT WHEN DESIRED

Our goal with the Rosette Series was clear from the start and our commitment to excellence has guided us to what we feel is the FIRST ACCURATE Acoustic Instrument Combo Amplifier and DI Preamp/Pedal.

OVERVIEW: FRONT PANEL

In Rosette, we opted for architecture straight from high-end recording console designs. We 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, we 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.

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 our 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. We’re not about to let the latter happen on our watch.

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.

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.

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 we 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..

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 its speakers connected is 100% safe and allows you to play through and/or record silently with the amp with headphones (or the amp’s DI Outputs – or both). The HEADPHONE OUTPUT will efficiently drive any headphones with an impedance between 8 to 32 Ohms. We suggest researching and auditioning headphones before you buy as the performance can vary substantially between manufacturers and impedances.

A Channel MUTE FTSW Jack is provided to allow remotely controlled muting of the Channels. The MUTE FTSW Input is fitted with a stereo (Tip / Ring / Sleeve) jack with the Tip controlling Channel 1 MUTE and the Ring controlling Channel 2 MUTE. MESA sells Rosette specific Mute footswitches separately through our Authorized Dealers and Distributors, our Parts & Accessories Online Store, or by contacting our Customer Service department.

The FX BYPASS FTSW Jack accepts a mono ¼” cable and Tip to Ground ON/OFF footswitch to bypass the internal Effects and/or any external effects that may be inserted in the FX Loop. MESA sells FX bypass footswitches separately through our Authorized Dealers and Distributors, our Parts & Accessories Online Store, or by contacting our Customer Service department.

Next up are the FX LOOP SEND & RETURN Jacks. These mono jacks are provided as a Parallel Loop interface for connecting external effects processors and pedal effects between the amp’s preamp and power section. Both the SEND (Output) and RETURN (Input) are optimized for a Line Level signal, so external processors should have their Input and Output configured for the same signal level whenever possible. The FX SEND level is controlled by each channel’s Front Panel FX SEND control. The FX SEND can also be used as an additional ¼” Line Level Output when nothing is connected to the FX RETURN Jack.

Comprehensive, studio-quality DIRECT OUTPUT features dedicated XLR Outputs with PRE/POST EQ, MIC or LINE LEVEL and GROUND or PIN 1 LIFT switches. Additionally, a third XLR Jack, with Ground or Pin 1 Lift Switch, delivers a properly summed output of both channels preset to POST EQ & POST FX and switchable between MIC & LINE level, and a

The AUX INPUT is provided to allow connection of external music sources through your Rosette amplifier such as a CD player, mobile device, drum machine, and computers or DAWs used for audio playback and accompaniment. Use the device’s volume control to achieve its desired listening level in balance with your instrument as all controls except the MASTER are inactive in this signal path.

Finally, the Rosette features a comprehensive, studio-quality DIRECT OUTPUT Section. Channel 1 & 2 have dedicated XLR Outputs with PRE/POST EQ, MIC or LINE LEVEL and GROUND or PIN 1 LIFT switches. Additionally, a third XLR Jack, with Ground or Pin 1 Lift Switch, delivers a properly summed output of both channels preset to POST EQ & POST FX and switchable between MIC & LINE level. Beyond its thorough features and thoughtful layout, it’s the great TONE and exceptional low noise of Rosette’s DI Outputs that sets it apart from the competition. For live and recording, Monitor, Front of House and Recording engineers will thank you when they hear the clean, quiet and accurate signal the Rosette DI delivers. This comprehensive, Toneful DI is nearly worth the price of admission alone, especially as the signal that feeds your acoustic voice to live venues and recording applications with something as important as your music.