MESA BOOGIE 20/20 Owner's Manual The Spirit of Art in Technology 1317 Ross Street Petaluma, CA 94954 USA
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 the all new 20/20 power amp, bred of fine all tube amp heritage...
20/20 TABLE OF CONTENTS Precautions Overview ________________________________________________________________________ 1 Instant Gratification Hook-Up _______________________________________________________ 2 FRONT PANEL CONTROLS: Presence ________________________________________________________________________ Volume __________________________________________________________________________ Power ___________________________________________________________________________ Standby ___________________________
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: Do not expose amplifier to moisture, rain or water, direct sunlight or extremely high temperatures. Always insure that amplifier is properly grounded. Always unplug AC power cord before changing fuse or any tubes. When replacing fuse, use only same type and rating. Avoid direct contact with heated tubes.
20/20 Operating Instructions OVERVIEW: Congratulations ...you have just become the owner of the most “Tone Full” one and three quarters inches of rack guitar power available on todays’s market. Don’t let the one rack space size fool you - this small amp packs a BIGGER than life voice and has been designed to handle all of what you’d expect and probably more from an amp this size.
Instant Gratification Basic Hook-Up Diagram: Front Panel of Mesa/Boogie Formula Pre-Amp IN FT.SW. GAIN RHYTHM RECORD LO GAIN EQ EQ IN GAIN FT MASTER SW BASS MID TREBLE LD2 IN HI GAIN MESA BOOGIE LEAD 1 60Hz 240 750 2200 6600 O U T P U T MASTER RHYTHM ON LEAD 2 AC LD 1 FT SW Formula Pre SHIELDED CABLE Back Panel of Mesa/Boogie Formula Pre-Amp (partial view) 117 V~ 1 AMP 60 HZ.
FRONT PANEL CONTROLS: 2A SB 20/20 DYNA-WATT POWER PATENTED 4,713,624 PRESENCE: POWER PATENTED 4,713,624 PRESENCE FUSE PRESENCE VOLUME POWER 1A SB SB STANDBY VOLUME PRESENCE EL-84 ALL TUBE STEREO HANDBUILT IN USA These controls “open-up” the 20/20 producing brightness and sparkle for clean sounds at higher settings or sizzle and edge when set high for distortion sounds. At lower PRESENCE Control settings you can darken and compress lead sounds making them warmer and fatter.
FRONT PANEL CONTROLS: (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 2 amp Slo-Blo fuse. A power tube short or failure is often the cause of a blown fuse...
REAR PANEL: (Continued) SPEAKERS: (Continued) Speaker cabinets may be 4, 8 or 16 Ohms and can vary from one manufacturer to another. If you are not sure of the impedance rating of your cabinet, you may need to remove the cabinet’s rear panel in order to verify the impedance rating of the speaker (s). Mesa/Boogie 4x12 and 4x10 cabinets come standard wired to 8 Ohms and are wired in series-parallel. No matter how unusual your speaker setup, it is always possible to get good performance from your 20/20.
TUBE LAYOUT and TASKS 20/20 REAR PANEL (cut-a-way view looking down from the top of unit) MESA MESA MESA MESA MESA 12AX7A 12AX7A 12AX7A 12AX7A 12AX7A V7 V5 V6 V4 V3 MESA MESA 12AX7A 12AX7A V2 V1 THESE 4 TUBES LEFT SIDE 12AX7 EL-84 12AX7 RIGHT SIDE TUBE ASSIGNMENT V1 - A = Channel B Input Stage V1 - B = Channel A Input Stage V5 = V6 = V2 - A = V2 - B = V7 - A = V7 - B = V3 = V4 = Phase Inverter for Channel B Power Tubes for Channel A Phase Inverter for Channel A Power Tube
20/20 Personnal Settings Page 2A SB 20/20 DYNA-WATT POWER PATENTED 4,713,624 FUSE PRESENCE VOLUME POWER 1A SB EL-84 ALL TUBE STEREO SB STANDBY VOLUME PRESENCE HANDBUILT IN USA SB STANDBY VOLUME PRESENCE HANDBUILT IN USA SB STANDBY VOLUME PRESENCE HANDBUILT IN USA SB STANDBY VOLUME PRESENCE HANDBUILT IN USA SB STANDBY VOLUME PRESENCE HANDBUILT IN USA SB STANDBY VOLUME PRESENCE HANDBUILT IN USA SB STANDBY VOLUME PRESENCE HANDBUILT IN USA 2A SB 20/20 DYNA-WATT POWE
Parts Sheet - 20 / 20 - Front Panel LIGHT Pt # 395620 20/20 DYNA-WATT POWER PATENTED 4,713,624 KNOBS (BOTH) Pt # 408111 POT Pt# POT Pt# 592151 592151 PRESENCE VOLUME POT Pt# 2A SB POWER SWITCH Pt # 601073 1A SB SB STANDBY POT Pt# 592151 592151 VOLUME PRESENCE FUSE SWITCH Pt # 601073 EL-84 ALL TUBE STEREO HANDBUILT IN USA KNOBS (BOTH) Pt # 408111 PAGE 8 FUSE CAP Pt # 790347 Parts Sheet - 20 / 20 - Rear Panel A INPUT B 8 OHMS 4 OHMS 4 OHMS ALL JACKS Pt# 613111 A SLAVE B
MESA BOOGIE The Spirit of Art in Technology Thank you for trusting MESA/Boogie to be your amplifier company. We wish you many years of toneful enjoyment from this handbuilt all tube instrument.
The Spirit of Art in Technology 1317 Ross Street Petaluma, CA 94954 USA Phone No. 707-778-6565 FAX No.
