Page 2
Greetings from the Home of Tone Congratulations on your choice of the Rectifier Pre as your Guitar amplifier and welcome to the MESA/Boogie family! As a discriminating player you probably know that you have purchased the most comprehensive instrument for amplifying Guitar that is available.
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.
OVERVIEW: Congratulations on your choice of the Rectifier Recording Preamp and welcome to the Mesa/Boogie Family! This all-tube, two rack space instrument is the latest in the legendary Rectifier line of amplifiers and after two years of intense R & D, is ready to wear the logo that signifies its status as a full blown Recto.
Rectifier Recording Preamp REAR VIEW : WARNING To reduce risk of fire or WARNING To reduce risk of fire or electric electric shock, replace fuse with shock, Do not remove cover. No user- same type and rating only. Do not serviceable parts inside.
Helpful Hints: Continued If you have less than satisfactory results with this instrument after reading the manual and believe it to be operating normally; we suggest either trying some different playback monitors or, taking it to you nearest dealer to try it through a different setup. In our tests we have found the playback monitors to be a huge part of the equation and that some are not very friendly to overdriven guitar sounds.
FRONT PANEL CONTROLS: INPUT / FT.SW. First remove the protective covers from the tubes (plastic webbing) before connecting the A.C. cord to a power receptacle. INPUT: Connect your favorite guitar to the instrument INPUT jack. Flip the POWER switch to the ON position while leaving the STANDBY switch set to STANDBY.”...
FRONT PANEL CONTROLS: (Continued) CHANNEL 2 MODES: RAW: This Recto mode is the lowest gain of the three in CHANNEL 2 s’ high gain lead channels. Its less saturated nature greatly enhances the already versatile bevy of sounds the two original lead channels offered. The range of gain available covers an extremely wide spectrum and it can be set to double as a formidable alternate clean mode, a low gain purring blues sound and beyond, all the way up to a grinding crunch or searing solo sound.
FRONT PANEL CONTROLS: (Continued) GAIN: (Continued) As a general guideline, the lower regions of this control produce brighter, tighter, faster sounds with enhanced dynamics...the higher the GAIN Control setting - the warmer, fuller, more saturated and more compressed ( less dynamic ) the sound becomes.
FRONT PANEL CONTROLS: (Continued) TREBLE: As with most guitar amplifiers, the TREBLE Control is the strongest of the three rotary tone controls. Its setting on the Recto Recording Preamp determines the blend and strength of the MIDDLE and BASS Controls. Set high, it is the dominant control, thus minimizing the amount of Mid and Bass that would be possible in the mix.
FRONT PANEL CONTROLS: (Continued) PRESENCE CONTROL: (Continued) CHANNEL 2 PRESENCE is extremely important in achieving the desired lead and crunch rhythm sounds. It responds like a focus or spread control for high gain chording sounds and for solo sounds it does a great job of compressing or putting the sound forward.
FRONT PANEL CONTROLS: (Continued) CHANNEL SELECT: This three position mini toggle selects which of the two channels is active when the footswitch is not in use. It is located in a convenient Front Panel location to make channel selection easy in the studio where it might likely be hardwired in to a system or patch bay. Set in its center FOOTSWITCH position with the footswitch connected via a stereo cable, the channels may be accessed remotely by toggling between them with the FOOTSWITCH CHANNEL button.
FRONT PANEL CONTROLS: (Continued) LIVE - SOLO: (Continued) Channel format. The controls will affect both sounds, so you will not be able to dial up independent Channels, but when used with the companion power amp (Rectifier Stereo 2:100) this little trick can be quite effective. This “smart power” amp tracks the preamp mode and switches the negative feedback circuit to match the Mode in use on the Recto Pre.
This style of power cord will make tear-downs and cable routing a lot easier and save you time as well. If you should ever need a replacement, just call and we’ll be happy to send you another one for a nominal charge or visit your nearest Mesa/Boogie Pro Center. LIFT...
REAR PANEL CONTROLS: (Continued) FX MIX CONTROL & EFFECTS LOOP: (Continued) The MIX Control has a range that roams between 10% and 100% of the wet blend. It is not possible to completely remove the parallel signal from the EFFECTS LOOP path with the FX MIX Control (this is due to a decision made by us to preserve the maximum tonal performance while the LOOP is in use).
SAMPLE HOOK-UP CLEAN BRIGHT BRIT STANDBY POWER INPUT GAIN TREBLE BASS PRESENCE MASTER FT.SW. OUTPUT OUTPUT LIVE SOLO LIVE CHAN BRIGHT CH 2 FOOT VINT -3DB VOICING SWITCH WARM MODERN RECORD CHAN WARNING To reduce risk of fire or electric shock, replace fuse with same type and rating only.
REAR PANEL CONTROLS: (Continued) EXTERNAL SWITCHING JACKS: These three 1/4” jacks make it possible to trigger the two channels of the Recto Pre with an external switching device so that it can be used in a midi controlled rack system. In this scheme the channels can be called up under midi programs. The jacks respond to any tip-to-ground latching type switch logic.
REAR PANEL CONTROLS: (Continued) LIVE OUT: To Power Amp The Recto Pre provides two output channels for feeding signal to either stereo power amplifiers, effects processors (see EFFECTS LOOP - presented earlier in the Rear Panel section of this manual) or even the effects return or power-in stages of self contained amplifiers.
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...by simply swapping out a pre-amp or power tube! First may we suggest that you set the amplifier up on something so that you can get to the tubes comfortably without having to bend down.
Page 23
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;...
BIAS ADJUSTMENT: (part of a continuous series) BEAM- CONFINING An Article written by Randall Smith that ELECTRODE CATHODE we thought you might find interesting. GRID ..SCREEN ..GRID PLATE .
Page 25
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.
Page 26
Mesa/Boogie players you couldn’t estimate. Our rigorously tested and hand selected tubes are available at your nearest Mesa/Boogie Pro Center or from us directly. Nobody offers better price, quality or warranty than we do ... so why swerve? Next time we’ll talk about our part in developing the great Sylvania STR 415 type 6 6 and how we’re on the verge of seeing something fairly...
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.
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.
Page 29
WIRING SCHEMES...Amplifier to Speaker Cabinets Partial back view of amplifier Partial back view of amplifier 8 OHM 4 OHM 4 OHM 8 OHM 4 OHM 4 OHM 8 Ohm Cabinet Partial back view of some Mesa amp 8 OHM 4 OHM 4 OHM 4 Ohm Cabinet 8 Ohm Cabinet...
Page 30
WIRING SCHEMES...Amplifier to Speaker Cabinets Partial back view of amplifier Partial back view of amplifier 4 OHM 4 OHM 8 OHM 8 OHM 4 OHM 4 OHM 16 Ohm Cabinet 8 Ohm Cabinet 8 Ohm Cabinet 8 Ohm Cabinet SAFE MISMATCH CORRECT MATCH Partial back view of amplifier Partial back view of amplifier...
Page 31
WIRING SCHEMES...Amplifier to Speaker Cabinets Partial back view of amplifier 16 Ohm 4 OHM 4 OHM 8 OHM SERIES BOX 8 Ohm 8 Ohm 8 Ohm Cabinet 8 Ohm Cabinet 8 Ohm Cabinet SAFE MISMATCH Partial back view of amp Partial back view of amplifier CORRECT MATCH 8 OHM...
Page 32
WIRING SCHEMES...Amplifier to Speaker Cabinets Partial back view of amplifier 16 Ohm 4 OHM 4 OHM 8 OHM SERIES BOX 8 Ohm 8 Ohm 8 Ohm Cabinet 8 Ohm Cabinet 16 Ohm Cabinet SAFE MISMATCH Partial back view of amplifier 8 OHM 4 OHM 4 OHM...
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.
Page 34
ON TRIODES, PENTODES & IRISHMENT: (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 stricly enforced at Irish pubs: During normal operation, the traffic flow is similarily unimpeded and uni-directional toward the bar and this process rectifies the work-day negativity.
Page 35
ON TRIODES, PENTODES & IRISHMEN: (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.
Rectifier Recording Preamp 602112 SWITCH pt# 607101 SWITCH pt# SWITCH pt# 607303 602112 SWITCH pt# CLEAN POT# POT# POT# POT# POT# POT# BRIGHT 592792 592148 BRIT 592379 592148 592148 592792 STANDBY POWER INPUT GAIN TREBLE BASS PRESENCE MASTER FT.SW. OUTPUT LIVE SOLO OUTPUT...
Page 37
OOGIE 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.
Page 38
The Spirit of Art in Technology (707) 778-6565 FAX NO. (707) 765-1503 1317 Ross Street Petaluma, CA 94954...
Need help?
Do you have a question about the Preamp Rectifier Recording and is the answer not in the manual?
Questions and answers