Mesa Boogie Express Plus 525 User Manual

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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. We feel confident, this amp will
inspire many hours of musical satisfaction and lasting enjoyment. It was built with you in
mind, by players who know the value of a fine musical instrument and the commitment it
takes to make great music. The same commitment to quality, value and support we make

to you...our new friend.

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. A polarized plug has two blades with one wider than the other. A grounding type plug
has two blades and a third grounding prong. The wide blade or the third prong are provided for your safety. If the provided plug does not fit into your outlet,
consult an electrician for replacement of the obsolete outlet.

Protect the power cord from being walked on or pinched particularly at plugs, convenience receptacles, and the point where they exit from the apparatus.

Only use attachments/accessories specified by the manufacturer.

Unplug this apparatus during lightning storms or when unused for long periods of time.

Refer all servicing to qualified service personnel. Servicing is required when the apparatus has been damaged in any way, such as power-supply cord or plug
is damaged, liquid has been spilled or objects have fallen into the apparatus, the apparatus has been exposed to rain or moisture, does not operate normally,
or has been dropped.

To insure proper ventilation always make sure there is at minimum four inches (101.6mm) of space behind the rear of the apparatus. The ventilation should not
be impeded by covering the ventilation openings with items, such as newspapers, tablecloths, curtains, etc. Do not impede ventilation by placing objects on top
of the apparatus which extend past the rear edge of its cabinet.

No naked flame sources, such as lighted candles, should be placed on the apparatus.

The apparatus shall not be exposed to dripping or splashing and no objects filled with liquids, such as vases, shall be placed on the apparatus.

WARNING: To reduce the risk of fire or electric shock, do not expose this apparatus to rain or moisture.

The AC plug is the mains disconnect. The plug should remain accessible after installation.

WARNING: EU: permission from the Supply Authority is needed before connection.

WARNING: Always make sure proper load is connected before operating the amplifier. Failure to do so could pose a shock hazard and may result in damage

to the amplifier.

Do not expose amplifier to direct sunlight or extremely high temperatures.

Always insure the amplifier is properly grounded. Always unplug AC power cord before changing fuse, tubes or removing chassis. Use only same type and
rating when replacing fuse.

Avoid direct contact with heated tubes. Keep amplifier away from children.

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 when handling buttons, switches and controls. Do not use solvents such as benzene or paint thinner to clean the unit.

Always connect to an AC power supply that meets the power supply specifications listed on the rear of the unit. Export models: always insure unit is wired for
proper voltage. Make certain grounding conforms with local standards.

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

Your Mesa/Boogie Amplifier is a professional instrument. Please treat it with respect and operate it properly.

READ AND FOLLOW INSTRUCTIONS OF PROPER USAGE.

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Table of Contents

Precautions _______________________________________________________________________________ 0
Overview ________________________________________________________________________________ 1-2

FRONT PANEL CONTROLS & FEATURES

MODES: CLEAN, CRUNCH, BLUES, BURN ____________________________________________________ 3-4
INSTANT GRATIFICATION, HELPFUL HINTS _____________________________________________________ 5
GAIN _____________________________________________________________________________________ 6
TREBLE __________________________________________________________________________________ 6
MID ______________________________________________________________________________________ 7
BASS _____________________________________________________________________________________ 7
REVERB __________________________________________________________________________________ 7
MASTER __________________________________________________________________________________ 8
EQUALIZER SECTION _____________________________________________________________________ 8-9
PRESET DEPTH CONTROL __________________________________________________________________ 9
CHANNEL POWER SELECT ______________________________________________________________ 10-11
SOLO CONTROL __________________________________________________________________________ 11
CHANNEL SELECT ________________________________________________________________________ 11
POWER __________________________________________________________________________________ 12
STANDBY ________________________________________________________________________________ 12

REAR PANEL CONTROLS, SWITCHES & JACKS

FUSE ____________________________________________________________________________________ 13
FOOTSWITCH JACK _______________________________________________________________________ 13
EXTERNAL SWITCHING ____________________________________________________________________ 13
EFFECTS LOOP ___________________________________________________________________________ 14
SPEAKERS ____________________________________________________________________________ 14-15

FACTORY SAMPLE SETTINGS _______________________________________________________________ 16
PERSONAL SETTINGS _____________________________________________________________________ 17
DIAGNOSING TUBE PROBLEMS __________________________________________________________ 18-19
BIAS ADJUSTMENT ARTICLE ____________________________________________________________ 20-22
SPEAKER IMPEDANCE MATCHING AND HOOKUP GUIDE _____________________________________ 23-28
FEATURE ARTICLE: ON PENTODES, TRIODES & IRISHMEN by Randall Smith ____________________ 29-31
TUBE TASK CHARTS: 5:25+ & 5:50+ _______________________________________________________ 32-33
PART SHEETS: 5:25+ & 5:50+ _____________________________________________________________ 34-35

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Operating Instructions

Overview:

Congratulations on choosing one of the Express Plus models as your amplifier and welcome to the MESA Family! These amplifiers
represent the latest generation of a time-proven circuit that has been evolving over the last 27 years. With inspiring Tone and a layout
that’s intuitive and easy to navigate, it’s no wonder this model has become one of our most popular line of instruments.

We use the term instrument literally because you will quickly come to rely on the myriad of truly Expressive sounds in your amp as it
becomes an integral part of your tone and your individual voice. Feel confident that, just like a fine musical instrument, we handcrafted
your all-tube amplifier here in Petaluma, California adhering to a code that is centuries old…where patience and scrutiny are guiding
every step on the way to excellence.

Both Express Plus models use the same super versatile, tone-packed preamp featuring two fully independent Channels, each of
which contain two style enhanced modes to choose from when creating your footswitching preferences. Channel 1 hosts the bloom­ing low-gain sweetness of CLEAN or the snarling mid-gain percussiveness of CRUNCH and covers the rhythm territories. Channel 2
offers a different face to mid-gain with the howling honesty of BLUES or a high-gain adventure through the searing layers of molten
harmonics in BURN. Together these two inspiring modes invite years of solo exploration.

These stylistically opposing modes in the two Channels enable your Express Plus to roam many different genres of music with com-
plete legitimacy. The R&B, Roots or Blues minded player would find themselves at home with Channel 1 set to CLEAN and Channel
2 set to BLUES, while the Rock, Metal or Punk influenced guitarist would likely prefer switching between CRUNCH and BURN. This
ability to reconfigure the Channels and morph personalities creates a Jekyll/Hyde platform from where any classic or modern tone
you are aiming at can be found in seconds. The ability to adapt is part of what defines a classic instrument.

Now the Express Plus features a dramatic enhancement in the EQ department with the inclusion of our time-honored 5 Band Graphic
Equalizer! The SLIDERS are added in addition to the original Channel Assignable PRESET contour controls and you can now choose
whether you want to use the SLIDERS or the PRESET in each Channel with the EQ Assign mini toggle. The EQ, whether set to call up
the SLIDERS or the PRESET controls, is also footswitchable as well and can be called up at any time via the Express Plus Footswitch.

FRONT VIEW: Express 5:25+

REAR VIEW: Express 5:25+

™

EQ ON

O

1

FT SW

EQ

SLIDERS

EQ ON

O

2

FT SW

80Hz 240 750 2200 6600

™

5:25+

SLIDERS

PRESET

PRESET

SLIDERS

PRESET

1

EQ

PRESET

DEPTH

2

SOLO

25 W

CH 1 CH 2

15

5 W

120V~

60 Hz

SOLOEQ

FOOTSW.

1 A

6,724,897

7,602,927

PAGE 1

Overview: (Continued)

FRONT VIEW: Express 5:50+

REAR VIEW: Express 5:50+

SOLOEQ

FOOTSW.

120V~

3 A

60 Hz

3 A

™

EQ ON

O

1

FT SW

EQ

SLIDERS

EQ ON

O

2

FT SW

80Hz 240 750 2200 6600

™

5:50+

SLIDERS

PRESET

PRESET

SLIDERS

PRESET

1

EQ

PRESET

DEPTH

2

SOLO

50 W

CH 1 CH 2

25

5 W

6,724,897

7,602,927

Rich all-tube REVERB enhances the spatial quality of your Express Plus and each Channel provides an independent Reverb Mix
control so you can get the perfect blend of this beautiful effect for each of your footswitchable sounds. The Reverb effect can be trig­gered on and off via the included Footswitch.

Outboard Processing is handled by the series EFFECTS LOOP, keeping patching to a minimum and protecting tonal integrity a priority.
The Express Plus amplifiers are compatible with most good quality processors and using this feature for all of your rack-type effects
will produce gratifying results.

Both Express Plus models, the bouncy 25 watt 5:25+ with its 2xEL84 9-pin power tubes and the bolder 50 watt 5:50+ running 2x6L6
octal-base pentodes, feature our patented Multi-Watt™ power switching. This valuable feature allows you to run the output tubes in
three different wattage ratings per Channel – very cool right? But what’s amazing is this – each power mode has it’s own tone-spawning
operating class and wiring configuration! Choose the full power mode of either amp (25W in 5:25+ or 50W in 5:50+) for Class AB
running in a Push-Pull configuration for punch, authority and headroom. Or, kick down to 15 watts (25 watts on the 5:50+) for Class
A Pentode for a more silky, vintage voice with enhanced clip potential. And for the ultimate in low wattage power expression knock
it down to the 5 watt mode… now you’re running one tube in Class A Pentode wired in a Single-Ended configuration. Obviously we
were thankful the patent office saw the possibilities and rewarded our efforts with a patent, but what excites us is the look on players
faces when they hear and feel this power section magic for the first time. The Express 5:25+ also features our patented Dyna-Watt™
Power that creates a time-specific burst of headroom at the initial attack of the notes that far exceeds the rated power of the circuit
and gives the 5:25+ an incredible sound and feel all its own.

Now that you have an overall picture of the features in your new Express Plus, let’s move on to the specific modes and features.

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FrONT PANeL: CONTrOLS & FeATureS

THe MODeS

CHANNEL 1

CLEAN:

clean chording sounds. The CLEAN mode has the greatest dynamic range of all the modes as the signal here is not compressed
with any additional gain as are the other three sequentially. Because of this more traditional gain structure, many players that are

the 2:30 – 4:30 range a soft fur will begin giving way to a vintage style break-up and finally at its maximum setting (5:30) the signal
will be fairly pushed and overdriven. Keep in mind that these are approximate descriptions of the sound and that your own personal
playing style, guitar, pickups and most of all touch, will determine how this mode reacts at specific settings.

CRUNCH:

retain as much dynamic range as possible. It cleans up nicely at the lower end of the GAIN control (9:00 – 12:00) and therefore can
be used as an alternate type of clean sound, though it will always retain a bit more aggressive midrange and will not have as much
top end sparkle as CLEAN.

This is the lowest gain of the four modes in your Express Plus and it is voiced to deliver beautiful sparkling and warm

looking for a vintage style response from the Express Plus should be at home here. At higher GAIN settings
this mode delivers great old school lead sounds and if you are a player that is reliant on overdrive pedals for a
certain sound (although we greatly encourage you to explore the other three modes – especially BLUES - for
overdriven applications), CLEAN will likely be the best match for retaining more dynamic range.

The taper of the GAIN control is calibrated such that at the lower settings 9:30 - 11:00 the sound will be very bright
and skinny “and” as you approach 12:00 – 2:00 warmth and richness appears and the signal stays clean. From

This mode excels at higher gain rhythm sounds and though it is quite a bit gainier than the CLEAN mode, it’s voiced to

Between 12:00 – 2:30 is where the classic rock rhythm sounds live, especially with humbucking pickups and
mahogany guitars. This is a sound that is overdriven, crisp and urgent, but not overly saturated. From 2:30 on
up to the maximum GAIN setting (5:30), the sound becomes more saturated and begins to get a bit thicker and
creamier. This region is great for solo sounds where more urgency is needed, as it has ample gain but is still
tight tracking and responsive.

Be sure to experiment with the Graphic EQ (try the classic “V” setting) and The PRESET feature in the CRUNCH mode as some
amazing sounds appear as a result of this combination. We tend to like the PRESET set at 12:00 with the GAIN at around 4:00 for
a great rock rhythm sound. Again, these are approximate settings as everyone will have different styles, guitars, pickups and touch.

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FrONT PANeL: CONTrOLS & FeATureS (Continued)

CHANNEL 2

BLUES:

playing as well if the GAIN controls are set in their lower regions. BLUES is the lower gain of the two modes in this Channel and owns
the zone between the CLEAN and CRUNCH modes. It delivers a classic, old-school voice that can be set to achieve anything from
a warmer clean sound, through a purring, soft-clip break-up on up to a mournful, howling lead sound.

When using the PRESET feature with the BLUES mode, you will likely find the best results in the lower range of the control (9:30 –
1:00). Above this region the mid-dip EQ curve of the PRESET can get a little too extreme for most players searching for bluesy solo
sounds. However, this same curve can be a benefit to creating sweeter, more sparkling clean sounds as its mid-dip scoops some of
the heavier mids that are needed for a fat single note sound, but can be a bit clunky for a great clean.

Also be sure to check out combining the BLUES mode with the 5 Watt Power setting to explore some really cool low-volume Blues
magic. The single-ended wiring scheme utilized here produces a sweetness that enhances the BLUES mode perfectly… not to men­tion that your roommates will love you for it.

Channel 2 is aimed more at single note soloing, although both of the modes contained in this channel work well for rhythm

Because it derives its architecture more from a medium gain lead circuit, it will always be a little warmer and
thicker than the CLEAN mode even at the lowest regions of the GAIN control. Therefore, if you wish to use
BLUES as an alternate clean sound or, you prefer to use Channel 1 set to CRUNCH for an urgent lead sound
and BLUES as your main clean, you will need to run the GAIN very low (9:30), the TREBLE higher (1:30 – 2:00)
and the MID low (8:00 – 9:30). Following this scheme will give you the closest approximation of the scoop and
sparkle present in the CLEAN mode.

BURN:

Channel. As mentioned in the Overview, this circuit has been evolving over the last 27 years and after you’ve dipped your guitar into
this river of undulating harmonics, you’ll come away a new soloist…baptized by gain that’s inseparable from the notes. Tight and

(2:15 – 5:30) the smoldering intensity of this channel is unleashed to produce a sound that is pure molten MESA. Legato and fluid, yet
with beam-like clarity and sustain, BURN is testimony that 42 years ago on a mountainside in Marin County…we invented high gain.

Perhaps no other mode in your Express Plus showcases the power and sonic potential of the GRAPHIC EQ and the PRESET feature
like BURN. Here, the entire range of the PRESET control produces useful and in fact, phenomenal high gain sounds. The lower
(8:30 – 11:00) range combined with lower GAIN settings works great for widening mid-gain single note solo sounds, while higher
settings (11:30 – 5:30) combined with more GAIN unveil a wall of crushing aggression that can be similar to our own Dual Rectifier™
line. Once you’ve auditioned the curve of the PRESET control, you can engage the EQ SLIDERS and begin shaping your own custom
curve. Be sure to explore this hellacious realm of sounds when you’re ready for some really big guitar sounds.

This is the highest gain of all the modes in your Express Plus and it is BURN that characterizes Channel 2 as the Lead

focused, searing yet vocal, BURN delivers the ultimate in Expressive high-gain.

At the lower end (8:30 – 9:30) of the gain range you will find a small overlap with the top zone of the BLUES
mode, although a bit fatter and more saturated, that offers some cool Blues or Roots melody line possibilities.
The similarities end abruptly here and a wide region of amazing Rock sounds appear in the middle range (9:45
– 2:00) of the GAIN control. This is where you will likely find the most musical and versatile of your high-gain
sounds…small adjustments here can make big changes in the attack and the body of the notes. From there on up

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FrONT PANeL: CONTrOLS & FeATureS (Continued)

INSTANT GRATIFICATION

Sweet Clean / Howling Blues

EQ ON

O

1

FT SW

EQ

SLIDERS

EQ ON

O

2

FT SW

80Hz 240 750 2200 6600

SLIDERS

PRESET

PRESET

SLIDERS

PRESET

1

EQ

PRESET

DEPTH

2

SOLO

25 W

CH 1 CH 2

15

5 W

Big Crunch / Burning Lead

EQ ON

O

1

FT SW

EQ

SLIDERS

EQ ON

O

2

FT SW

80Hz 240 750 2200 6600

SLIDERS

PRESET

PRESET

SLIDERS

PRESET

1

EQ

PRESET

DEPTH

2

SOLO

25 W

CH 1 CH 2

15

5 W

HELPFUL HINTS

1. The Controls are powerful. You will find great performance using most of the Controls set in their middle ranges and not in the
extreme regions of their sweep. Try this approach first and venture beyond for specific needs.

2. As you increase the GAIN control – decrease the BASS control. This is a good practice throughout the Modes as it helps keep
the sounds tracking accurately and helps avoid a loose, flubby attack. It is also advisable when searching for the maximum
headroom for rhythm playing in the CLEAN mode.

3. Use the EQ Section as a seasoning element and not the main course. Dial in your sounds in the Modes with the rotary Tone
Controls first and then engage the EQ for fine-tuning. (Exception: High Gain Crunch or Metal sounds – Use Sliders set to “V”
curve or PRESET around 2:00.

4. Single 12” speaker should be connected to the 8 Ohm SPEAKER OUTPUT. Two 8 Ohm speakers should be connected to the 2
x 4 Ohm jacks (or one 4 Ohm jack if using a 2x12 wired to 4 Ohms.)

5. When using the EFFECTS LOOP, Delay, Reverb, Chorus, Flange, Harmonizers (virtually all “time-based” processors) and outboard
Equalizers work well at this point in your signal path. When using Overdrive pedals, Wah-Wah, Envelope Filters and most other
processors that affect the “guitar’s signal” and aren’t among those mentioned above, it is best to use them on the “front end” of
the amplifier – between the instrument and the INPUT jack. This is not a hard and fast rule and deviating will not damage the
amplifier, but the above wiring scheme will deliver the best tonal results and signal to noise ratio.

6. It is always preferable to have the combo - or extension cabinet if using a head - on the floor. This helps couple the low end and
improves both the Tone you hear and the tactile sense you feel when playing. If you need the controls up higher to more easily
reach them or want the sound to be aimed higher for projection on low stages, you might try adding an extension cabinet to your
setup. However you achieve it, your amp will sound bigger and wider with at least one cabinet in contact with the floor.

Now let’s move to the individual controls and go over how they interact to achieve the sound you’re looking for.

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FrONT PANeL: CONTrOLS & FeATureS (Continued)

EQ ON

FT SW

O

O

EQ

SLIDERS

EQ

PRESET

EQ ON

PRESET

DEPTH

FT SW

SLIDERS

PRESET

SLIDERS

PRESET

5 W

15

CH 1 CH 2

25 W

SOLO

80Hz 240 750 2200 6600

1

2

1

2

GAIN:

As with all tube amplifiers, especially those with higher GAIN circuits, the GAIN control is by far the most powerful control

in the amplifier. It determines the overall GAIN amount you will be working with (how clean or saturated the signal is) in any given

channel or mode by metering the signal in the beginning stages (first tubes) of the preamp. It is also a very
important Tone control as well.

Generally speaking, lower the settings of the GAIN control (below 12:00 in all modes) produce sounds that
are less saturated, cleaner, brighter and more dynamic. As the GAIN control is increased the sound begins to
get thicker and warmer and the dynamic peaks get softened by natural, sweet tube compression as the signal
moves toward saturation. This is pretty much an across the board (or Channels) response, as these global
behavior traits remain constant regardless of the individual architecture of the modes themselves.

Another simple guideline to follow that might make dialing for your sounds easier is this; as the GAIN goes up…the BASS should
come down. Following this scheme will help you avoid flub and retain a tight, focused attack.

So for example, if you are in Channel 1 CRUNCH and you want to max the GAIN (5:30) for a rhythm sound, you would want to run
the BASS control somewhere around 10:30 or lower to keep the sound tracking tight. In the BLUES mode of Channel 2, things would
be a bit more flexible. If you wanted to run the GAIN just high enough to have a nice fury break-up when you lean into it (1:00 – 2:00),
you will be able to run the BASS a little higher (11:00 – 12:00) because there is less GAIN in the mode to begin with and you are not
using an extreme setting of the GAIN control.

NOTE: If you need very high GAIN settings to achieve the type of sound you are after, try looking to the CONTOUR for any added
low-end enhancement as this circuit comes later in the preamp and is less likely to “bloat” the sound. If the top-end enhancement is
unwanted, reduce the TREBLE.

Just remember that as the internal gain structure of the Modes gets increased across the Channels, so does the need to carefully
blend the GAIN and BASS, and in fact all the controls, to keep balance and cohesiveness in your Tone.

NOTE: Avoid extreme settings of both GAIN and TREBLE at the same time as the likelihood of annoying microphonic tube problems
increases. If you need one set high to achieve the sound you are after, reduce the other to ensure uninterrupted performance.

TREBLE:

As in most tube guitar amplifiers, the TREBLE control (in both channels of your Express Plus) is the most powerful of the

rotary controls and is next in line only to the GAIN control as a shaping tool. Because it is first in the signal path of the tone controls

- and from here the Middle and Bass receive their signal - it is by far the dominant tone control. For this reason the
setting of the TREBLE control is very important for equal representation of the three frequency regions to appear at
their respective controls. Like most of the controls on your Express Plus, there is an optimum region of the TREBLE
control where ample top end is mixed in and yet enough signal is still passed on to the MIDDLE and BASS controls.

As you might surmise, here is the sweet spot. There are definitely great sounds above and below this middle region
(11:00 - 1:30), but the balance between the TREBLE control and the other two tone controls is compromised.

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FrONT PANeL: CONTrOLS & FeATureS (Continued)

EQ ON

FT SW

O

O

EQ

SLIDERS

EQ

PRESET

EQ ON

PRESET

DEPTH

FT SW

SLIDERS

PRESET

SLIDERS

PRESET

5 W

15

CH 1 CH 2

25 W

SOLO

80Hz 240 750 2200 6600

1

2

1

2

EQ ON

FT SW

O

O

EQ

SLIDERS

EQ

PRESET

EQ ON

PRESET

DEPTH

FT SW

SLIDERS

PRESET

SLIDERS

PRESET

5 W

15

CH 1 CH 2

25 W

SOLO

80Hz 240 750 2200 6600

1

2

1

2

EQ ON

FT SW

O

O

EQ

SLIDERS

EQ

PRESET

EQ ON

PRESET

DEPTH

FT SW

SLIDERS

PRESET

SLIDERS

PRESET

5 W

15

CH 1 CH 2

25 W

SOLO

80Hz 240 750 2200 6600

1

2

1

2

MID:

The MID control is responsible for the blend of midrange frequencies in the mix and though its effect is not as dramatic as

that of the TREBLE control, it plays an integral part in achieving any sound in your Express Plus. It is capable of changing the feel

dramatically as it blends in a group of frequencies that tend to soften or stiffen the way a sound feels to play.

Most players tend to lean in the direction of lower MID control settings (7:00 - 11:00) where a scoop in this region pro­duces girth (by letting the Bass become a little more dominant) and a lack of punch lends a more compressed, even
feel to the strings and therefore less apparent resistance to the pick. As the MID control is increased, (11:30 - 1:30) the
sound is rounded-out and 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 MID 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. While these MID control settings (2:00 - 5:00) can introduce added gain and create enhanced focus,
the trade-off will be a stiffer, more forward, less compressed feel.

BASS:

The BASS control in your new Express Plus works similarly in both channels in that it determines the amount of low fre-

quencies present in a sound. However, the style of lows it mixes in changes from channel to channel. Like the MID control, it falls in line

signal-wise after the TREBLE control and the same scheme applies. When the TREBLE control is set high, the effective­ness of the BASS and MID controls is reduced. If the TREBLE control is set low these two controls become dominant.

For the most balanced sound and a balance of power between the three rotary tone controls, try to use the TREBLE
control in its middle ranges. This scenario produces nearly equal representation of all the frequencies on the tone controls
and provides a great neutral starting point for further tweaking.

Note: The BASS control in both channels of your Express Plus is very powerful and though we have taken steps to ensure

a balanced tone is easy to achieve, it is wise to blend with subtle nuance in mind. A good rule to follow is this; as you increase the
GAIN reduce the BASS. Following this scheme will retain balance and keep the attack of the notes tight, dynamic and touch sensitive.

REVERB:

Your new Express Plus amplifier is equipped with a rich, natural sounding all-tube Reverb circuit. The REVERB control

enables you to dial-in just the right amount of Reverb to be mixed with the dry signal. It is normal for extreme settings of the REVERB
control to slightly alter the character of the amplifier as the voicing of the Reverb circuit becomes more dominant in the mix.

NOTE: Avoid using high setting the REVERB control when High Gain and Treble settings are in use. This reduces the

likelihood of annoying microphonic problems occurring.

PAGE 7

FrONT PANeL: CONTrOLS & FeATureS (Continued)

EQ ON

FT SW

O

O

EQ

SLIDERS

EQ

PRESET

EQ ON

PRESET

DEPTH

FT SW

SLIDERS

PRESET

SLIDERS

PRESET

5 W

15

CH 1 CH 2

25 W

SOLO

80Hz 240 750 2200 6600

1

2

EQ

PRESET

PRESET

DEPTH

SLIDERS

PRESET

SLIDERS

PRESET

5 W

15

CH 1 CH 2

25 W

SOLO

240 750 2200 6600

1

2

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 both channels relative volumes to be matched regardless of their

extremely different sound styles and gain signatures. The MASTER control makes possible a wide range of sounds
through its ability to use very low Gain sounds at high volumes and conversely, high Gain sounds at low volumes

1

and everywhere between.

Again, we suggest using the MASTER control in its sensible ranges (9:00 - 2:00). Here, the channels will be easier

2

to match with each other and the Effects Loop will see more reasonable signal levels.

NOTE: Because the MASTER control creates the send to the Effects Loop, extreme settings will cause a large
signal to be sent to the Loop for that Channel. Not only may this cause possible overloading of the processors Input stage, but will
make balancing both channel’s Effect Send level difficult.

EQUALIZER SECTION:

This section of the Express Plus offers two additional ways to further shape your sound beyond

what the standard array of rotary Tone Controls can do. The choices are either the classic Boogie 5 Band Graphic EQ or our PRESET
DEPTH Control - which uses the same EQ circuitry to create a dial-able EQ version on one control that is pre-shaped to the iconic
mid-dipped “V” slider setting. These choices are channel specific so that you can use either SLIDERS or PRESET for each Chan­nel. Once you’ve chosen which option you want to use for each Channel, they can be auto-engaged when the Channel is selected,
brought in and out via the Footswitch or Bypassed altogether.

Here are the switches, controls and the functions they perform to control the EQ section.

EQ CONTROL: Toggle

These two stacked 3-position mini-toggles to the Left of the SLIDERS (one for each Channel) in the

EQ Window selects if and how you wish to engage the EQ Section – EQ ON, OFF or FT SW. Between the two mini-toggles in the

centerline between the Channels, is an Orange LED that indicates when the EQ SLIDERS are engaged. When this

EQ ON

O

1

FT SW

EQ

SLIDERS

EQ ON

O

2

FT SW

light is illuminated, the EQ circuit is Active and you may use the SLIDERS to shape your sound (to use the PRESET

Control, select PRESET with the EQ Style switch to the Right of the SLIDERS).

The Middle position of each switch (O) Bypasses the EQ section altogether and both SLIDERS and PRESET will

not have any effect on the signal.

80Hz

The Upper position of each switch (EQ ON) engages the EQ section in that Channel. Whatever is selected on the
EQ STYLE mini- toggle (to the right of the SLIDERS) will determine the type of interface that is active in that Channel… SLIDERS
or PRESET.

The Lower position of each switch (FT SW) allows you to engage the EQ section from the Express Plus Footswitch. The Footswitch
EQ button may not turn the EQ on or off if the EQ Control switch is set to either EQ ON or O (switch up or switch middle) as these
positions override the Footswitch EQ button.

PAGE 8

FrONT PANeL: CONTrOLS & FeATureS (Continued)

PRESET

DEPTH

5 W

15

CH 1 CH 2

25 W

SOLO

PRESET

DEPTH

5 W

15

CH 1 CH 2

25 W

SOLO

1

2

5 W

15

CH 1 CH 2

25 W

SOLO

EQ STYLE - Toggle:

These two stacked 2-position mini-toggles to the Right of the SLIDERS (one for each Channel) determine

the style of interface you wish to utilize to control the EQ circuit. As mentioned earlier, there are two ways to use the EQ circuit – the

traditional Graphic EQ SLIDERS and the PRESET DEPTH Rotary Control. Just between these switches (on the centerline
between the Channels) is located a Red LED that indicates the PRESET circuit and Rotary Control are active. When this

SLIDERS

1

LED is illuminated, the PRESET control is engaged and the 5 SLIDERS have no effect on the signal.

PRESET

EQ

PRESET

SLIDERS

The SLIDERS position allow you to dial in specific curves on the “graph” to suit your individual needs for different instru-

2

ments, playing styles and room variations.

PRESET

The PRESET circuit does the work for you and puts the shaping power of the EQ under one simple rotary control that you
can turn up and down quickly. The PRESET uses the same circuit as the SLIDERS and sets the “EQ Curve” internally to the classic
“huge-approved” mid-dipped “V” setting.

NOTE: The indicator LED above the EQ button on the Footswitch is a dual-color type that tracks the colors on the Front Panel EQ
LED indicators. It will appear orange for SLIDERS and change to green when PRESET is activated.

GRAPHIC SLIDERS:

These are the five fader style potentiometers for the Graphic EQ. They are centered on the five frequency

points we’ve found most effective for shaping guitar sounds quickly and accurately. So that they are “less tweaky” and interact smoothly.

They incorporate a fairly wide “Q” and are each capable of 12db of cut or boost.

EQ ON

O

FT SW

EQ

SLIDERS

EQ ON

O

FT SW

80Hz 240 750 2200 6600

SLIDERS

By far the most widely used is the 750Hz, which is used most often to cut midrange and create a

PRESET

EQ

scoop that makes the sound wider and more three-dimensional. Usually this mid cut is combined

PRESET

SLIDERS

with a boosting of the 80 and 240 Hz as well as the 2200 and 6600 bands as well. This creates

PRESET

the classic “V” setting that so many Rock and Metal players rely upon for their huge crunch sound.
While this is the most popular setting, there are many uses for the Graphic EQ from subtle enhance­ment to wild alteration of the signal and your own imagination is the only limit to the possibilities.

PRESET DEPTH CONTROL:

The PRESET DEPTH control takes the place of the 5 EQ Sliders as the interface to the EQ

Circuit when you’ve selected PRESET on the EQ STYLE switch. As you increase the PRESET DEPTH Control from 7:00 / Off (a flat

setting equivalent to all 5 SLIDERS set on the Center Graph Line) through its range, the mids start to dip and both low

SLIDERS

PRESET

PRESET

SLIDERS

PRESET

1

EQ

2

and high end are slowly boosted - until at 5:30 (maxed out) - you have an extreme mid-dipped “V” setting. This dial-able
enhancement allows for some subtle applications of the EQ circuit at the low end of the control that can be superior to

PRESET

the SLIDERS for certain sounds because it acts as an EQ “mix” control at these lower settings.

DEPTH

For example, apply a slight bit of the PRESET to make chording sounds blossom in CLEAN - or turn it up just a bit
more to add bounce and girth to rhythmic parts in the BLUES Mode. This PRESET EQ treatment works well for all the

MODES, but showcases its true power most in the CRUNCH and BURN MODES - where this “V” curve produces some
radical and now iconic Rock and Metal Crunch chording sounds. This sound has been a live power-tool as well as a much-recorded
staple of Rock and Metal guitarists that have played our MARK Series models for decades. Now this dual-option EQ comes straight
from our Flagship MARK FIVE to greatly enhance the flexibility of the Express Plus.

PAGE 9