Mesa Boogie Formula Pre User Manual

M

ESA

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OOGIE

Owner's Manual

The Spirit of Art in Technology

1317 Ross Street Petaluma, CA 94954

USA

Hello from the Tone Farm...

Congratulations on your choice of the Formula Pre-Amp and welcome to the Mesa/Boogie
family! We salute your obviously discerning taste in tone and feel sure that this instrument
will exceed your expectations and provide you with years of inspiration and service.

The latest in a long line of Mesa all-tube multi-channel pre-amps, the Formula shares
common roots with all these earlier rack classics and then goes beyond to capture the best
qualities of the Heartbreaker...our roots oriented tribute to the original Mark I. The first
amplifier ever to offer guitarists a high gain lead channel that could produce singing sus­tain at any volume. Thus the little Mark I Boogie earned its place in history as the crucial
link between vintage and modern guitar amplification.

TABLE OF CONTENTS

REAR PANEL:

Precautions _________________________________________________________________________ 0
Overview ___________________________________________________________________________ 1
Important Note About Power ___________________________________________________________ 2
Hook-Up ____________________________________________________________________________ 3

FRONT PANEL:

Instrument Input _____________________________________________________________________ 4
Footswitch DIN Jack _________________________________________________________________ 4
Record Voicing ______________________________________________________________________ 4

CONTROLS: (Controls)

Gain ___________________________________________________________________________ 4 & 5
Treble ______________________________________________________________________________ 5
Mid ________________________________________________________________________________ 6
Bass _______________________________________________________________________________ 6
Master _____________________________________________________________________________ 6
5 Band Graphic EQ __________________________________________________________________ 7
Output _____________________________________________________________________________ 7
Channel Select ______________________________________________________________________ 8
Power ______________________________________________________________________________ 8

A.C. Power Cord Receptacle ___________________________________________________________ 9
Fuse _______________________________________________________________________________ 9
Ground Lift _________________________________________________________________________9
Effects Loop & Mix Control ______________________________________________________ 10 & 11
External Switch Jacks _______________________________________________________________ 11
Record Outputs_____________________________________________________________________ 11
Signal Levels__________________________________________________________________ 11 & 12
Main Outputs_______________________________________________________________________ 12
Tube Bay _____________________________________________________________________ 12 & 13
Tube Task Chart ____________________________________________________________________14
Factory Sample Settings ________________________________________________________ 15 & 16
Personal Settings Page _________________________________________________________ 17 & 18
Parts Sheet ________________________________________________________________________ 19

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 A.C. power cord before changing fuse or any tubes

When replacing fuse, use only same type and rating

Avoid direct contact with heated tubes.

Insure adequate air circulation around amplfier.

Keep amplifier away from children.

Be sure to connect to an A.C. power supply that meets the power suplly specifications listed on the
rear panel of the unit.

If there is any danger of lighting occurring nearby, remove the power plug from the wall socket in
advance.

To avoid damaging your speakers and other playback equipment, turn off the power of all related
equipment before making the connections.

Do not use excessive force in handling buttons, switches and controls.

Remove the power plug from the A.C. mains socket if the unit is to be stored for an extended
period of time.

Do not use solvents such as benzene or paint thinner to clean the unit. Wipe off exterior with soft
cloth.

Be sure to have the warranty card for this product filled out by the store at which it was purchased
and return to Mesa Engineering promptly.

YOUR AMPLIFIER IS LOUD! EXPOSURE TO HIGH SOUND VOLUMES MAY CAUSE

PERMANENT HEARING DAMAGE!

No user serviceable parts inside. Refer service to qualified personnel.

EXPORT MODELS: Always insure that unit is wired for proper voltage. Make certain grounding

conforms with local standards.

READ AND FOLLOW INSTRUCTIONS OF PROPER USAGE.

Operating Instructions

OVERVIEW:

The Formulas’ one space chassis is power packed with features and as you can see, available real estate is used
carefully in an effort to retain a clean, simple layout. Three incredible channels reward you with some of the most soulful sounds ever
to come out of Mesa/Boogie, let alone in a rack format!

The top Channel 1 (Green/Rhythm) is a lower gain circuit that is undeniably black face in lineage and is capable of pristine clean
sounds, full of warmth and character in its lower region of settings. As gain is increased this channel finesses the precarious crossing
between clean and pushed with a realm of languid gain that is subserviant to expression...served up by subtle changes in pick attack.
For more agressive rhythm work there is a Pull Boost function fitted to the Gain control that increases saturation and this range of
sounds allow Channel 1 to grind away for crunch rhythm, or double as a valuable solo channel.

The bottom channel is actually two channels in one, as the rotary controls are shared between Lead 1 (Orange/Vintage) and Lead
2 (Red/Modern). Each of these two channels has its own independant Gain/Master harness - Lead 1 in the same bottom row of
controls - and Lead 2s’ Gain and Master in a stacked format over to the right of the 5 Band Graphic EQ. Internal changes occur when
switching between them which produces a wonderful difference in personality and readjustment of the tone controls is not necessary
to achieve two amazing and different lead sounds.

Lead 1 is the more creamy of the two sounds and could best be described as Brown in nature. Set low it purrs, quite capable of furry
chording and as the gain is increased a violin-inspired liquid gain voice emerges that soars with emotion. Lead 2 is more urgent and
focused by nature and roams defiantly from a stinging low-gain bluesy region on up to a blistering high-gain frontier. Although Lead 2
undergoes internal re-voicing that makes the shared rotary controls work well in both channels with the same settings, we know some
players will need extreme differences in these two sounds. Therefore, the 5 Band Graphic EQ may be assigned to Lead 2 automati­cally every time it is called up via the front panel mini toggle or footswitched at will via the Foot Controller EQ switch.

What really sets the Formula apart from other Mesa Pre-Amps before it, is not the amazing tone and versatility for live applications,
but rather that it was - from the inception - a recording pre-amp. A new type of direct RECORD circuit that responds in frequency to
dynamic fluctuations in signal strength the same way a power amp and speakers do, proved to be one of the Formula’s strongest

FRONT VIEW: Formula Pre

IN FT.SW.

ESA

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B

RECORD

LO GAIN

HI GAIN

REAR VIEW: Formula Pre

OOGIE

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117 V~

CIRCUIT PATENTS PENDING

1 AMP
60 HZ.

LIFT

10%

GROUND

HANDMADE IN CALIFORNIA

FX MIX

100%

FX SEND
RHY - LD

GAIN

EXT
SW

RETURN - L

LD1 - LD2

TREBLE

EXT
SW

RETURN - R

EQ

RHYTHM

EQ IN

MASTER

FT

SW

EQ LD2

LEAD 1

60Hz 240 750 2200 6600

LEFT

REC
OUT

TIP

RING

SLEEVE

MAIN

OUT

BASS

RIGHT

MID

PAGE 1

GAIN

O
U

EQ

T

LD2

P

IN

U
T

MASTER

RHYTHM

LD

1

FT
SW

LEAD 2

Formula Pre

ON

AC

attributes. Directing the emphasis early on in the R & D process toward the recording environment, this new reactive circuit captures
the sound - but even more importantly the feel - of a great head and cab set-up.

To assist in seamless interfacing of outboard signal processing for either live or recording applications we have included a Stereo
Parallel Effects Loop with a Mix control. The Send is mono and the Returns appear as Left and Right 1/4” phone jacks. The loop
handles both line and instrument level signals depending on the settings of the channel Masters, as they control the Sends’ level
strength, with line level being the preferred choice. Both the Main and Recording Outputs are fed by the effects loop so that when
recording direct with your live effects set-up you will retain the processing you are familiar with in the signal sent to the console.

IMPORTANT NOTE: Before we go much further, we would like to take a minute to talk about power. Your new Formula Pre-Amp was
designed with the utmost consideration given to ensuring that, while it delivers the versatility of three distinct channels, it retains all the
warmth and expressiveness of its tube heritage. Rack separates have been criticized in the past as not having the same vibe or soul
as self-contained guitar amplifiers. While we view this as a gross generalization, we do subscribe to the idea that any system is only
as strong as its weakest link. Many players accidentally get into rack guitar with products that concentrate on effects, processing and
programmability, leaving the actual sound of the amplified guitar itself as an afterthought. Usually these stories end with the sale of
said gear at a considerable loss and a lingering bad taste for rack gear.

Most likely this is how the separate component world got its negative reputation among some players. Those of us who have used
tube rack gear for years know that just as much tone and far more versatility is available with these separate component systems...as
long as you follow the golden rule of rack mount guitar. Thou shalt use tube power and tube power only! This is the secret. A great pre­amp is essential, but it is only half of the equation. The expressive nature of an all-tube power section is crucial to achieving the
amazing tone and feel, and when comparing separates to self-contained amplifiers this is often overlooked.

For this reason, we strongly recommend that you use your new Formula with one of our four Mesa/Boogie all-tube stereo rack
mount power amplifiers. These handbuilt rack classics have been the power behind most touring and recording artists for the last
decade - and in fact it was the ancestors of these amps, that first introduced guitarists to rack mount power back in 1982 with the M-
180 and M-190 mono blocks. These beasts were the power behind L.A.’s first big session rigs in the early 80’s.

Since then, Mesa has led the rack guitar revolution by going stereo, incorporating switchable voicing options and steadily shrinking
the packages from four to three to two and finally now, down to an unbelievable one space for the spicy little Stereo 20/20. All these
power amplifiers have been designed to give the rack player every measure of tone and nuance found in a self-contained amplifier
and more. So save yourself the time and aggravation and try one of these companion instruments first and you’ll never miss that
combo again.

The choices are (In order of popularity);

STEREO SIMUL-CLASS 2:NINETY - 2 Space / 90 Watts per channel / 8 x 6L6
FIFTY/FIFTY STEREO - 2 Space / 50 Watts per channel / 4 x 6L6

20/20 STEREO - 1 Space / 20 Watts per channel / 4 x EL84

COLISEUM 300 STEREO - 4 Space / 150 Watts per channel / 12 x 6L6

All these power amps are a perfect match for the Formula and each one of them was designed with a style of player and venue
combination in mind. Obviously the two more extreme wattage arenas found in the lower power 20/20 and the higher power Coli-
seum 300 have a slightly narrower window of appeal. The 20/20 finds its home in the studio, small clubs and as a slave to bigger set­ups while the Coliseum is the big guns for the larger venues or heavier styles. The two middleweight amps, Simul-2/90 and Stereo
50/50 are the most popular, versatile and economical pound-for-watt. Therefore we will use these as the reference when we speak
of tone and settings throughout this manual. While we used all of the above amplifiers during the R & D process, our favorite amp has
always been the Simul-Class 2:Ninety for its silky warmth for solo sounds and sparkling scoop for clean playing.

Now that we have that bit of important info out of the way, let’s hook up the Formula to the power amp and run through some possible
sounds in the three channels.

PAGE 2

HOOK-UP DIAGRAM:

Run through the three channels with these settings to get familiar with the character of each channel. For
this exercise we have not auto-inserted the 5 Band Graphic EQ to LEAD 2 so that you may hear it unaltered first. Use the EQ switch
on the Foot Controller to add and delete the EQ on any of the three channels for now.

IN FT.SW.

OOGIE

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M

117 V~
1 AMP
60 HZ.

RECORD

LO GAIN

GAIN

HI GAIN

OOGIE

ESA

B

M

CIRCUIT PATENTS PENDING

LIFT

10%

GROUND

HANDMADE IN CALIFORNIA

FX MIX

IN

100%

MIDI

TREBLE

FX SEND
RHY - LD

OUT

RHYTHM

EQ IN

MASTER

REC
OUT

TIP

RING

SLEEVE

MAIN

OUT

FT

SW

LEAD 1

RIGHT

EQ LD2

60Hz 240 750 2200 6600

RETURN - R

EQ

BASS

LEFT

MID

RETURN - L

LD1 - LD2

EXT

SW

EXT
SW

GAIN

O
U

EQ

T

LD2

P

IN

U
T

MASTER

RHYTHM

LD

1

FT
SW

LEAD 2

Formula Pre

ON

AC

SHIELDED CABLE

STEREO (MONO) EFFECTS

LEFT

OUTPUT

RIGHT

LEFT

INPUTS

RIGHT

(MON0)

AC POWER

SHIELDED CABLE

STEREO SIMUL - CLASS 2: NINETY

B A

INPUTS

L
I

INPUT LEVEL

N
E

MODERN

DEEP

EXTEND

HALF

DRIVE

UNSHIELDED CABLE

B

SPEAKERS

B

I
N
S
T

8 OHMS

A

4 OHMS

4 OHMS

UNSHIELDED CABLE

A

PAGE 3

Now that you have a better understanding of the layout and features of your new Formula, we can move on to the individual controls

INPUT:

FOOTSWITCH:

RECORD VOICING:

GAIN:

and take a look at their role in obtaining the sounds you want to dial.

FRONT PANEL:

This 1/4” jack is the instrument Input for the Formula. The input impedance is 1 meg ohm which should be optimum for

most all applications where your instrument is feeding only one source. When connecting your instrument to multiple sources you may

need to buffer the signal. If you plan to use the Formula in this type of set-up at all times, call us and we

IN FT.SW.

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This is the 5-pin DIN input for the Formula’s 4 button Footcontroller. The Front panel Channel Select toggle (next
to Power - left side of chassis) must be in the center position for the Footcontroller to operate. The Footcontrollers’ power-up default
will be Lead 1 (Orange) before any choices are made. If you ever misplace the cable, most 5-pin DIN or standard midi cables available

IN FT.SW.

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can explain how to change the input impedance to better fit your particular application.

at most music stores will work fine.

Early on in the development process we realized that there was no way to treat the clean direct sounds and

the high gain direct sounds the same. In the end we arrived at the conclusion that for each sound to be the real thing, two complete

circuits were needed. This mini toggle lets you choose between a circuit voiced specifically for low

IN

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FT.SW.

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RECORD

LO GAIN

HI GAIN

gain clean sounds and one tailored for high gain lead work.

LO GAIN (up) should be used for clean rhythm playing in the top Rhythm channel. It is voiced so that
all the sparkling high end harmonics are retained and a fast dynamic attack is preserved - as well as

allowing the sub-lows to pass sounding breathy and warm. You may also prefer the LO GAIN setting
for certain lower gain sounds in the two lead channels to keep the top end a little more up front and attack oriented...this setting works
real well for blues type styles.

HI GAIN (down position) is optimized for gain sounds. The right high frequencies are rolled back substantially - to avoid the dreaded
buzzy quality that can so often dominate direct guitar sounds - while at the same time the lower attack region is relatively untouched.
(Extreme settings at the front end GAIN control will produce natural tube saturation which will affect the attack characteristics substan­tially.) HI GAIN may also be used to shape the sound when you are using the PULL SHIFT function of the Rhythm (top) channels’
GAIN control for either crunch or gainier single note sounds. In this application the EQ and feel will be much better suited than that of
the LO GAIN position. The HI GAIN circuit is tranformer coupled much like a power amp and therefore reacts similarly in terms of
response to the dynamic changes in your playing.

The two circuits provide you with the ability to zero-in on just the right sound and feel for each style of playing. You may feel free to
experiment as to the best way to use them for your recording techniques and music. Though they are labeled specifically, many great
sounds may be found by cross applying them. Thus the Formula is a dedicated recording pre-amp.

CONTROLS:

This is probably the most powerful control on your Formula. There are three of these riding on the front panel: two heading

IN FT.SW.

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RECORD

LO GAIN

HI GAIN

GAIN

up the two stacked rows of rotary controls and another
just to the right of the Graphic EQ. In all three channels,
the setting of the GAIN control determines the sensitivity

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GAIN

O
U

EQ

T

LD2

P

IN

U
T

MASTER

RHYTHM

LD

1

FT
SW

LEAD 2

Formula Pre

ON

AC

TREBLE:

GAIN:

CONTROLS:

(Continued)

(Continued)

of the front ends’ first tube stage and therefore, the overall character of the given channels’ sound style. Set
low, it allows more of the natural sound of the instrument to come through. Set higher, an increasing amount of natural tube saturation
occurs. Run all the way up, it produces overdrive saturation in all channels...with the two LEAD channels being obviously capable of
significantly more of this saturation. The amount of saturation is accompanied by tonal coloration as this control is turned upward and
the result is a perfect enhancement to the gain. Top end harmonics become more and more recessive as the GAIN is increased and
a warmer, more singing nature takes over. This is perfect for liquid high gain solo work in LEAD 1 and the added focus also lends
authority and urgency to LEAD 2 for more aggressive rock or metal styles. The lower regions of the GAIN control are perfectly mated
to clean sounds in Channel 1 and pushed or bluesy styles in the two LEAD channels.

As the GAIN and inherent saturation are reduced, the high harmonic content returns to its original balance. This is where the Formula
shines for bubbly, sparkling clean chording in Channel 1 or less overdriven single note work in LEAD 1 & 2. You will find all three
channels’ GAIN controls use pots that support a touch sensitive relationship between input signal strength - and gain saturation.
These pots were custom built for us with tapers capable of delivering the maximum usable range of musical gain in all ranges. This
elusive trait is crucial to a great amps’ expressive nature and you will come to love the Formulas’ responsiveness in this dynamic
dance. We suggest spending some time really exploring the subtleties of this most powerful control. The Rhythm (top) channel of your
Formula has a Gain control pot that is fitted with a “Pull Boost”. This enables you to restructure the response of the channel for either
higher gain rhythm work or single note solo sounds that are in between the regular Rhythm and Lead channels gain-wise.

NOTE: This added gain is achieved in part by allowing the full signal strength to pass the tone control network, rendering them
virtually ineffective. Because of additional shaping that takes place elsewhere in the circuit, this is not a problem and the result is a
smooth warm medium gain response. If you need more critical shaping power in the “Boost” mode than that of the bypassed tone
control string, select the 5 Band Graphic Equalizer and shape your sound there.

Learn the regions of GAIN and the tonal colors they enhance. Slight adjustments make huge differences in the sound. In all of the
channels you will find sweet spots on the GAIN control that work with your technique, your guitar and your pick-ups to compliment,
embelish and finally define a sound that is all you.

As with most guitar amplifiers, the TREBLE control is the strongest of the three rotary tone controls. Because signal

enters the tone control string here, its setting determines the strength of the signal sent to the BASS and MID, greatly affecting their

role in the tonal blend. Set high, the TREBLE is the dominant force and the effectiveness

IN FT.SW.

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RECORD

LO GAIN

HI GAIN

GAIN

TREBLE

of the BASS and MID are substantially reduced.

Set low, the opposite occurs and the BASS and MID become dominant, producing a
warmer, darker personality. This interaction holds true for all the channels. For this rea-

son we strongly suggest using the TREBLE control with care as it can produce some
unwanted qualities in the sound when used without moderation. This especially holds true for clean sounds in Channel 1, where the
most beautiful and balanced sounds are found with the TREBLE set somewhere in the middle ranges. This way the BASS control can
produce enough lows for a breathier quality and the TREBLE is more sparkling instead of sticking out and becoming harsh.

There are occasions where you might deviate from this scheme and set the TREBLE control in the higher ranges. Because this
control is the first in the signal path and is responsible for the amount of GAIN that is fed to the other tone controls, it can be used to
further saturate the signal. For extremely high GAIN solo sounds in the two LEAD channels, you may want to experiment with setting
the TREBLE pretty high - not maxed - but higher to achieve a more blistering quality for single note work.

In this scenario it is usually helpful to reduce the PRESENCE control setting on the power amp to avoid a buzzy or shrill sound. The
top slider of the EQ also helps if the PRESENCE on the power amp is not quite the right frequency, or you are using the DIRECT
Output straight into a mixing console and there is no power amp. This added gain can also be used to push the envelope in Channel
1 for overdrive sounds, but you will have to again use care, as it is easy to go over the edge fast.

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