Owner’s Manual
Hello from the Tone Farm ...You, smart player and intuitive human, have put your trust in us to be your amplifier company. This is something we do not take lightly. By choosing this instrument to be a part of your musical voice, you have become part of the Mesa family...WELCOME! Our goal is to never let you down. Your reward is that you are the new owner of an amp, bred of fine all tube heritage...benefiting from the many pioneering and patented Mesa circuits that led to the refinement of your new model.
ROADSTER Table of Contents Precautions____________________________________________________________________________________ 0 Overview_____________________________________________________________________________________ 1-2 Getting Started_________________________________________________________________________________ 3 Helpful Hints_________________________________________________________________________________ 3-4 FRONT PANEL: MODES: Ch 1 & 2 CLEAN_______________________________________________________
IMPORTANT SAFETY INSTRUCTIONS Read these instructions. Keep these instructions. Heed all warnings. Follow all instructions. Do not use this apparatus near water. Clean only with dry cloth. Do not block any ventilation openings. Install in accordance with the manufacturer’s instructions. Do not install near any heat sources such as radiators, heat registers, stoves, or other apparatus (including amplifiers) that produce heat. Do not defeat the safety purpose of the polarized or grounding-type plug.
Operating Instructions Overview: Congratulations on choosing the Mesa Dual Rectifier Roadster as your amplifier and welcome to the Mesa/Boogie Family! By choosing this all-tube hand-built instrument you have taken a step into the future of guitar amplification, for as you can see at a glance, the Roadster is more than just an amp. It’s a collection of amps housed in one chassis.
Overview: (Continued) This allows the Roadster to be many amps to many players and roam confidently between extremely different musical styles while retaining the ability to focus in on any one and offer a multitude of great sounds for a specific genre. For example, a Blues player might dial up 1 & 2 for different clean sounds using the same mode for both chording and solo fills, while 3 4 provide different levels of the same lower gain solo sound.
Getting Started: 1.) After unpacking the amplifier remove the plastic webbing from all of the tubes (including the preamp tubes behind the row of power and rectifier tubes) and make sure all tubes are seated firmly in their sockets. 2.) Install the 5U4 Rectifier tubes (if they are not already in place) by bending back the spring steel tube clamps just enough so that the base of the tube will have to barely push the clamps out of the way as they go in.
Helpful Hints: (Continued) 7.) The PRESENCE control determines a lot about the voicing of gain sounds. Set lower it will fatten and compress single note sounds and lend a liquid feeling to the strings in the 3 modes of Channels 3 & 4. Set higher it will add cut and brightness to the sound and can be useful in keeping Bass response tight, especially at high GAIN settings when searching for crunch rhythm sounds. 8.
CHANNEL MODES: CHANNELS 1 & 2: CLEAN This is the lowest gain circuit of the Roadster’s twelve modes and is optimized for producing balanced pristine clean sounds. This mode is duplicated in CHANNEL 2 as it is extremely useful for many different CLEAN applications. For the best understanding of how to achieve a great sound in this mode, please refer back to the GAIN control section of this manual.
CHANNEL MODES: (Continued) CHANNEL 2: BRIT This mode appears in CHANNEL 2 only and, as the name implies, was inspired by the great sounding amps of the 50s’ & 60s’ that were built in Great Britain. These classic amplifiers were basically “upside down Leo circuits” but none the less had a signature sound all their own, due largely to the fact that they were powered by the pentode available to them at the time…the Euro style EL 34.
CHANNEL MODES: (Continued) CHANNEL 3 & 4: MODERN Aggressive. This is the word that best describes the menacing power of the Roadster’s most rebellious of all modes and appears in its original form in CHANNELS 3 & 4. A take no prisoners, crushing assault of top end cut and lightning fast response creates a sound of unparalleled aggression that has set a new standard for hard core sounds.
CONTROLS: (Continued) NOTE: Due to the Roadster’s extreme gain potential, the highest regions of the GAIN control may possibly push the pre-amp tubes past what they can handle, producing microphonic squealing. While we screen and test the tubes your amplifier was shipped with and the tubes in your amp passed our rigourous test, we can’t predict how the tubes will respond over time exposed to extreme gain settings.
CONTROLS: (Continued) MID: (Continued) filled-in with a focused mid attack appearing rather quickly. As you would guess, the feel starts to change - becoming more resistant. Above this region the MIDDLE control could be used to compensate for either weaker pick-ups or for times when a specific deficiency is produced by either an extremely high setting of other tone controls, or a physical anomaly in the room.
CONTROLS: (Continued) MASTER: This control is the master feed from the end of the pre-amp to the driver stage and the Effects Loop. As you can see each Channel is fitted with its own MASTER control, enabling the four channels relative volumes to be matched regardless of their extremely different sound styles and gain signatures.
CONTROLS: (Continued) SOLO: This control is an additional output control wired in parallel with the main OUTPUT that you can pre-set to a higher level and then switch to during performances. A simple idea that adds amazing potential to virtually any sound in the amplifier. Like the OUTPUT control, SOLO gets its signal from the EFFECTS RETURN jack and therefore it is only in the signal path and active when the EFFECTS LOOP is set to LOOP SYSTEM IN.
REAR PANEL CONTROLS & FEATURES REAR VIEW : COMBO Roadster REAR VIEW: Roadster Combo POWER FUSE 120 V~ 4 A 60 Hz SLO 4A BLO CH 2 CH 1 CH 3 FT SW CH3 CH2 SEND EXT.
REAR PANEL CONTROLS & FEATURES (Continued) CHANNEL STRIPS: These 4 clusters of switches and controls house the specific features that can be pre-assigned per individual channel. Once you have deciphered one, you have learned the Roadster’s secret and are ready to roll, for they are simply repeated for the 4 channels. CH 4 This section is where you choose the status of the LOOP, your power setting (50/100 watts), the type of Rectifier you wish to use and your Reverb Mix Level.
REAR PANEL CONTROLS & FEATURES (Continued) FX ON / FX OFF SWITCH: This mini toggle switch in each Channel Strip assigns the Series EFFECTS LOOP and determines its status in the signal path. Once the LOOP has been engaged, its Channel specific status is sent to the Front Panel FX LOOP LED indicator that sits between the pairs of Channels for at-a-glance monitoring of its status. See the DIODE 100 WATTS FX ON EFFECTS LOOP section for more information on the LOOP.
REAR PANEL CONTROLS & FEATURES (Continued) PATCHING EFFECTS: (Continued) You will find the FX LOOP a welcome feature for all rack type processing and when good quality cables are used and kept to a length of 3 feet or less, you will notice very little if any degradation in the sound of your Roadster. NOTE: Because the FX LOOP is wired in series with the main signal, it is very important that you choose processing devices that are of professional grade quality from reputable manufacturers.
REAR PANEL CONTROLS & FEATURES (Continued) USING THE FX RETURN AS A POWER AMP INPUT: (Continued) NOTE: When using the Roadster’s EFFECTS RETURN jack as a Power Amp Input, the input sensitivity will be most “normal” in CHANNELS 1 and 2. For increased power sensitivity you may choose the incredibly sensitive CHANNEL 3 or 4 MODERN mode. This will increase the power section input sensitivity by an order of ten.
REAR PANEL CONTROLS & FEATURES (Continued) FUSE: This is the A.C.’s (Alternating Current) main fuse and provides protection from outside A .C. fluctuations as well as power tube failure damage. Should the FUSE blow, replace it with the same rating in a Slo-Blo type package. The domestic U.S. version requires a 4 amp Slo-Blo fuse. A power tube short or failure is often the cause of a blown fuse...
FACTORY SAMPLE SETTINGS: CHANNEL 1 SETTING #1 Versa Clean CLEAN FAT TWEED GAIN TREBLE MID BASS DIODE 100 WATTS FX ON RECTO TRACKING 50 WATTS FX OFF DIODE 100 WATTS FX ON RECTO TRACKING 50 WATTS FX OFF DIODE 100 WATTS FX ON RECTO TRACKING 50 WATTS FX OFF DIODE 100 WATTS FX ON RECTO TRACKING 50 WATTS FX OFF PRESENCE MASTER CLEAN FAT BRIT CHANNEL 1 SETTING #2 Spank CLEAN FAT TWEED GAIN TREBLE MID BASS PRESENCE MASTER CLEAN FAT BRIT CHANNEL 1 SETTING #3 Tweed Howl CLEAN FAT
FACTORY SAMPLE SETTINGS: CHANNEL 2 SETTING #1 Skinny Skank CLEAN FAT TWEED GAIN TREBLE MID BASS DIODE 100 WATTS FX ON RECTO TRACKING 50 WATTS FX OFF DIODE 100 WATTS FX ON RECTO TRACKING 50 WATTS FX OFF DIODE 100 WATTS FX ON RECTO TRACKING 50 WATTS FX OFF DIODE 100 WATTS FX ON RECTO TRACKING 50 WATTS FX OFF PRESENCE MASTER CLEAN FAT BRIT CHANNEL 2 SETTING #2 Rhythm Mix CLEAN FAT TWEED GAIN TREBLE MID BASS PRESENCE MASTER CLEAN FAT BRIT CHANNEL 2 SETTING #3 Power Rhythm C
FACTORY SAMPLE SETTINGS: CHANNEL 3 SETTING #1 Purring Blues RAW VINTAGE GAIN TREBLE MID BASS PRESENCE MASTER MODERN DIODE 100 WATTS FX ON RECTO TRACKING 50 WATTS FX OFF DIODE 100 WATTS FX ON RECTO TRACKING 50 WATTS FX OFF DIODE 100 WATTS FX ON RECTO TRACKING 50 WATTS FX OFF DIODE 100 WATTS FX ON RECTO TRACKING 50 WATTS FX OFF RAW VINTAGE MODERN CHANNEL 3 SETTING #2 Smooth Grind RAW VINTAGE GAIN TREBLE MID BASS PRESENCE MASTER MODERN RAW VINTAGE MODERN CHANNEL 3 SETTING
FACTORY SAMPLE SETTINGS: CHANNEL 4 SETTING #1 Atlantic Blues RAW VINTAGE GAIN TREBLE MID BASS PRESENCE MASTER MODERN DIODE 100 WATTS FX ON RECTO TRACKING 50 WATTS FX OFF DIODE 100 WATTS FX ON RECTO TRACKING 50 WATTS FX OFF DIODE 100 WATTS FX ON RECTO TRACKING 50 WATTS FX OFF DIODE 100 WATTS FX ON RECTO TRACKING 50 WATTS FX OFF RAW VINTAGE MODERN CHANNEL 4 SETTING #2 Stripped Grind RAW VINTAGE GAIN TREBLE MID BASS PRESENCE MASTER MODERN RAW VINTAGE MODERN CHANNEL 4 SETT
TUBE NOISE & MICROPHONICS: You may occasionally experience some form of tube noise or microphonics. Certainly no cause for alarm, this quirky behavior comes with the territory and the Tone. Much like changing a light bulb, you don’t need a technician to cure these types of minor user serviceable annoyances and in fact, you’ll be amazed at how easy it is to cure tube problems...
DIAGNOSING PRE-AMP TUBE PROBLEMS: Because your amplifier is an all tube design, it is quite possible that you will at some point experience minor pre-amp tube noise. Rest assured - this is no cause for alarm and you can take care of the problem yourself in a matter of minutes by simply swapping tubes. Let us begin by saying; It is a “very good” idea to keep at least a couple of spare pre-amp tubes on hand at all times to insure uninterrupted performance.
BIAS ADJUSTMENT: (Part of a continuing series) An Article written by Randall Smith that we thought you might find interesting. CATHODE ( ) , ) GRID ( SCREEN GRID ( ) Here’s a question we often hear: “Why doesn’t Mesa put bias adjustments in their amplifiers?” Well, there’s a short answer and a long answer to this question. BEAMCONFINING ELECTRODE ( ) .. ..... . ... . ... .. ... PLATE ( , ) Structure of a 6L6 / 5881 Beam Power Pentode.
BIAS ADJUSTMENT: (Continued) control grids. Voltage and current are NOT the same. Current is the AMOUNT of electricity, the “quantity” — and is measured in amperes. Voltage is the degree of electric charge — like the “pressure” to use the old water analogy. Let me illustrate how different voltage and current are: When you scrape your feet across a carpeted floor in dry, wintery conditions, your body can become charged with 50,000 to 100,000 volts of static electricity.
BIAS ADJUSTMENT: (Continued) Again, this has some merit .. but it’s still not as good as using tubes that are matched in the first place because compensating for the mis-match causes the push-pull circuit itself to become unbalanced. Two wrongs don’t really make a right. Some of the other recommended biasing, “methods” — such as -”.. tubes running red hot, increase the bias .. sounds harsh and runs too cool, turn it down ...” are guesswork at best.
SPEAKER IMPEDANCE MATCHING & HOOK-UP GUIDE: IMPEDANCE: Wiring up speakers to provide the most effective load and making sure that all of them are in phase will help in creating the best sound possible. This is not too difficult, as long as you understand a few things about loading and how to connect your speakers to provide an optimal resistive load. MESA/Boogie amplifiers can handle 4 and 8 ohms effectively.
SPEAKER IMPEDANCE MATCHING & HOOK-UP GUIDE: (Continued) PARALLEL: When wiring in parallel, the resistance of the speakers decreases. Two 8 ohm speakers wired in ( hooked-up ) Parallel results in a 4 ohm load. It’s easy to calculate the effect of a resistive load when all the speakers are all the same resistance. It is really not suggested to wire different resistive load values in Parallel ( 8 and 4, 16 and 8 etc.
WIRING SCHEMES...
6 WIRING SCHEMES...
WIRING SCHEMES...
WIRING SCHEMES...
ON TRIODES, PENTODES & IRISHMEN: With apologies to Friends and Relatives from the Emerald Isle - who will make their appearance soon enough - the humor which follows is dedicated to the memories of Spec McAuliff and Fae (Rafael) McNally, two of the True Greats. As their numerical references suggest, the terms Diode, Triode and Pentode indicate the number of elements within the vacuum tube i.e. two, three or five. All tubes also require a filament or heater which is not included in the count.
ON TRIODES, PENTODES & IRISHMEN: (Continued) Thus a diode tube - one with a cathode and an anode - is mostly used to rectify alternating current into direct current by passing it without restriction, but in one direction only. This also explains why closing time is strictly enforced at Irish pubs: During normal operation, the traffic flow is similarly unimpeded and uni-directional toward the bar and this process rectifies the work-day negativity.
PENTODES: (Continued) Thus the proper cocktail waitress - visible through the louvers - is scantily clad so as to be all the more effective at reinforcing the attractive influence of her bar and by being located in between the door and the bar, she serves as bait to lure customers past the door’s negative influence.
12AX7 V2 12AX7 V3 12AX7 V5 6L6 V10 FRONT OF CHASSIS 12AX7 V4 Matched Pair Matched Pair 6L6 V8 12AX7 V6 5U4G 5U4G POWER TUBES 50 Watts = V9, V10 100 Watts = V7, V8, V9, V10 Roadster HEAD TUBE REPLACEMENT PAGE 36 INPUT JACK 12AX7 V1 6L6 V7 V4A- Reverb Return V4B- Reverb Driver 6L6 V9 V1A- Input Stage V1B- Second Gain Stage V5A- FX Loop Send V5B- FX Loop Return PREAMP TUBES V2A-3rd Gain Stage CH1/CH 2 V2B- 3rd Gain Stage CH3/CH 4 V6A&B- Phase Inverter/Driver TO MAINTAIN WARRANTY, USE
Roadster COMBO TUBE REPLACEMENT 12AX7 V6 6L6 V10 12AX7 V5 6L6 V8 12AX7 V4 Matched Pair Matched Pair 12AX7 V3 6L6 V7 6L6 V9 POWER TUBES 50 Watts = V9, V10 12AX7 V2 100 Watts = V7, V8, V9, V10 INPUT JACK 12AX7 V1 PAGE 37 FRONT OF CHASSIS 5U4G V4A- Reverb Return V4B- Reverb Driver 5U4G V1A- Input Stage V1B- Second Gain Stage V5A- FX Loop Send V5B- FX Loop Return PREAMP TUBES V2A-3rd Gain Stage CH1/CH 2 V2B- 3rd Gain Stage CH3/CH 4 V6A&B- Phase Inverter/Driver TO MAINTAIN WARRANTY, USE
590739 590148 590378 590150 590150 BASS 590378 MID 590148 TREBLE 590739 GAIN FRONT PANEL: ROADSTER SWITCH pt# 607313 CLEAN PUSHED CLEAN PUSHED FAT FAT SWITCH pt# 607313 INSTRUMENT INPUT JACK pt# 610120 CH3 CH2 LOOP EXT.
MESA BOOGIE The Spirit of Art in Technology Thank you for trusting MESA/Boogie to be your amplifier company and we wish you many years of toneful enjoyment from this handbuilt all tube instrument.
The Spirit of Art in Technology (707) 778-6565 FAX NO.
