MESA BOOGIE Owner's Manual
Hello from the Tone Farm... YOU, the smart player and all around intuitive human, have put your trust in us to be your amplifier company. This is something we do not take lightly. Our reward is that we've made a classic amplifier and by choosing this amplifier, you have become part of the MESA family...Welcome! Our goal is to never let you down. Your reward is that you are now the owner of our most popular selling power amp, the 2:100. Bred of fine all tube amp heritage...
TABLE OF CONTENTS Precautions OVERVIEW 1/2 FRONT PANEL CONTROLS & SWITCHES LEVEL CONTROLS PRESENCE POWER ON 2 2 3 STANDBY MODERN 3 3 REAR PANEL - SWITCHES & JACKS INPUTS A / B BIAS SWITCH GROUND LIFT SPEAKER JACKS TUBE BAY DRIVER TUBES 12AX7A AC RECEPTACLE LINE FUSE TUBE MAINTENANCE DIAGNOSING POWER TUBE FAILURE 4 4 5 5 6 6/7 7 7 8 DIAGNOSING PRE-AMP TUBE FAILURES & PROBLEMS Feature Article by Randall Smith On Bias Adjustment SPEAKER HOOK-UP GUIDE & IMPEDANCE MATCHING 9 10/12 13/14 POSSIBLE HOOK-
PRECAUTIONS & WARNINGS Your MESA/Boogie Amplifier is a professional instrument. Please treat it with respect and operate it properly. USE COMMON SENSE AND ALWAYS OBSERVE THESE PRECAUTIONS: WARNING: EU: permission from the Supply Authority is needed before connection. WARNING: Vacuum tube amplifiers generate heat. To insure proper ventilation always make certain there is at least four inches (100mm) of space behind the rear of the amplifier cabinet. Keep away from curtains or any flammable objects.
Operating Instructions Overview: Congratulations on your choice of the RECTIFIER STEREO 2:100 as your power amplifier and welcome to the MESA/Boogie Family. This 2 rack space unit is born of legendary stock and traces its lineage to the mighty Dual Rectifier Solo Head. Here the stunning performance of the Dual is faithfully recreated in a stereo format that duplicates the power section exactly when the Dual is set to its Silicon Diode rectifier setting.
Overview: (Continued) Without further delay, connect up your favorite preamp and get ready to experience one of the most commanding sounds in rack-mount history as Recto power goes stereo for the first time in this amazing package. NOTE: BEFORE YOU MOUNT THE 2:100 IN YOUR RACK! This is an extremely aggressive and powerful amplifier intended for use with one of the above mentioned MESA preamplifiers in large venues.
FRONT PANEL CONTROLS: (Continued) POWER SWITCH & POWER UP: First remove the protective covers from the tubes (plastic webbing) before connecting the A.C. cord to a power receptacle. ENGINEERING VEL A LEV MODERN ON ON Make all necessary connections including pre-amp, effects, speakers and instrument before you flip the STANDBY switch to its ON position. AC power is turned on via the POWER switch and indicated by the pilot lamp.
REAR PANEL FEATURES: REAR VIEW: 2:100 WARNING: To reduce risk of fire or WARNING: To reduce risk of fire or electric shock, Do not remove cover. No userserviceable parts inside. Refer servicing to qualified personnel. ENGINEERING GROUND BIAS SWITCH SWITCH LIFT 6L6 POWER FUSE NORMAL EL34 RECTO INPUTS 120 V~ 60 Hz 6A 6A SLO BLO GROUND MUST MATCH TUBES CHAN. B NORMAL SEE OWNERS BOOK FUSE RECTO INPUTS CHAN.
REAR PANEL (Continued) TUBE BIAS: (Continued) We recommend the 6L6 for reliability: In our many tests and continued use of the currently available EL34 type power tubes on the market today, we regret to say that they do not appear to be as rugged in construction as the available 6L6. This is another reason why your 2:100 was shipped with 6L6 power tubes.
REAR PANEL (Continued) SPEAKER OUTPUTS: (Continued) NOTE: If you opt to use only one channel of the 2:100 with speakers connected to that channel’s output only, you must turn the unused channel’s level control to zero! Otherwise the channel will be operating without a load, and damage to the tubes and/or the transformer will result. COOLING FAN TUBE BAY: The power tubes used in the 2:100 are MESA/Boogie STR-430 type 6L6 GC’s.
REAR PANEL (Continued) DRIVER TUBES: 3 x 12AX7A to grab hold of the particular pre-amp tube when replacement is required. Do not allow your fingers, hands or rings/jewelry to come into contact with any other part (s) of the amplifier’s internal circuitry. No other user serviceable parts exist in side. Refer service to qualified personnel. Always unplug AC power before removing the top cover of the amplifier. AC RECEPTACLE: The total power consumption for the 2:100 is 6Amps @ 120 Volts.
You may occasionally experience some form of tube noise or microphonics. Certainly no TUBE NOISE & MICROPHONICS 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 CATHODE ( ) GRID ( , ) SCREEN GRID ( ) Here’s a question we often hear: “Why doesn’t MESA put bias adjustments in their amplifiers?” BEAMCONFINING ELECTRODE ( ) .. ..... .. .. .. ... . .... PLATE ( , ) Structure of a 6L6 / 5881 Beam Power Pentode. Well, there’s a short answer and a long answer to this question.
BIAS ADJUSTMENT: (Continued) 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 carpetted 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...
WIRING EXAMPLE #1 117 V~ 1 AMP 60 HZ. Mesa/Boogie all tube Formula Pre-Amplifier ESA BOOGIE M CIRCUIT PATENTS PENDING LIFT 100% 10% GROUND RETURN - L LD1 - LD2 FX SEND RHY - LD RETURN - R EQ LEFT EXT SW EXT SW FX MIX REC OUT TIP RING SLEEVE RIGHT MAIN OUT HANDMADE IN CALIFORNIA SHIELDED CABLE 2:100 ALL TUBE STEREO POWER AMPLIFIER WARNING: To reduce risk of fire or electric shock, replace fuse with same type and rating only. Do not expose this unit to rain or moisture.
SUGGESTED WIRING #2 CLEAN ON ON FAT BRIGHT BRIT STANDBY INPUT FT.SW. GAIN TREBLE MID BASS PRESENCE MASTER OUTPUT LIVE BRIGHT CHAN 1 WARM RECORD 2 CHAN RAW CH 2 VOICING -3DB VINT MODERN OUTPUT POWER LIVE SOLO FOOT SWITCH WARNING: To reduce risk of fire or electric shock, replace fuse with same type and rating only. Do not expose this unit to rain or moisture. RECTO~PREAMP RECORD OUT ALL TUBE RECORDING AMPLIFIER 10% RETURN - L RETURN - R MODERN CH1 - CH2 SOLO EXT.
ON TRIODES, PENTODES & IRISHMEN: A look into the inner workings of the Vacumm Tube 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.
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 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.
ON TRIODES, PENTODES & IRISHMEN: ( Continued ) PENTODES: (Continued) stopping them. The influence of the plate takes over and - being solid metal and of the highest positive attraction - it is at this final destination that the electrons congregate.
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.
