Mesa/Boogie Mark IV Amplifier User Manual

This control along with RHYTHM 2’s PRESENCE control should be worked with together to produce the desired gain and brightness
of the mode. Setting the TREBLE higher, as always, increases the gain of the mode and allows increased distortion and sustain.
Lower settings allow the MID and BASS controls to become more dominant adding warmth to the
sound.
RHYTHM 2’s PRESENCE control also works on higher frequencies than the TREBLE, so by working with both controls, you can
produce any sound from fat and thick to searing and shredding. Don’t be surprised if loud group playing requires higher PRESENCE
control settings to cut through...this is why we’ve provided the three modes with their separate Presence
controls.
The RHYTHM 2 (and LEAD) PRESENCE control also has a PULL SHIFT feature. This Shift normalizes
the amount of high frequencies produced in the power section. With the PULL SHIFTS engaged, the
Presence controls will be more effective and will act on a higher frequency range. When the SHIFTS are pushed in, a punchier, more
aggressive tone is produced and the PRESENCE controls effectiveness is reduced.
This MASTER control is used to balance playing loudness in RHYTHM 2 and also determines the amount of RHYTHM 2 signal at the
Effects Send jack.
This control sets up the input sensitivity for the LEAD mode. The more signal strength dialed in here, early in the preamp, the more
distortion will be available at the LEAD DRIVE control. Yet it is not necessary or recommended to turn the LEAD GAIN fully up.
Best results will occur with settings in the
8
range. As you approach a Gain of
7
the Lead sound will
become extremely focused, rich and smooth; above
8
, total saturation occurs, reducing the effectiveness
of the tone controls and causing increased “microphonics” and noise in the preamp tubes. You’ll notice
subtle shifts in distortion tonality by trying different mixes of LEAD GAIN and LEAD DRIVE. The LEAD
GAIN control incorporates a PULL FAT for thickening the sound and saturating the signal further. This pull
shift lowers the frequency of the Treble, adding a boost in the lower midrange. Try this shift for beefing up
the sound of weaker, stock pick-ups or simply for adding focus at virtually any setting of the GAIN control.
CONTROLS: (Continued)
RHYTHM 2 TREBLE:
R2 TREBLE
R1 +R2 BASS
R1 +R2 MID
6
2
3
4
5
7
8
9
1
0
10
6
2
3
4
5
7
8
9
1
0
10
6
2
3
4
5
7
8
9
1
0
10
R2 PRESENCE:
R2 MASTER:
PAGE 5
SETTING THE LEAD MODE:
LEAD GAIN:
PULL SHIFT
TREBLE
PRESENCE
CONTROLS
R 1
6
2
3
4
5
7
8
9
1
0
10
6
2
3
4
5
7
8
9
1
0
10
6
2
3
4
5
1
0
R 2
2
3
9
1
0
10
PULL BRIGHT
MASTERS
LEAD DRIVE
R2 TREBLE
PULL
R 2
R 1
5
2
3
4
6
7
8
9
1
0
10
6
2
3
4
5
7
8
9
1
0
10
6
2
3
4
5
7
8
9
1
0
10
PRES
CONT
2
3
9
1
0
10
2
3
9
1
0
10
INPUT
PULL BRIGHT
INSTRUMENT
RHY2 GAIN
RHY1 GAIN
PULL FAT
PULL FAT
LEAD GAIN
5
2
3
4
6
7
8
9
1
0
10
6
2
3
4
5
7
8
9
1
0
10
6
2
3
4
5
7
8
9
1
0
10

Mesa/Boogie Mark IV Amplifier Specifications

General

Brand	Mesa/Boogie
Model	Mark IV Amplifier
Category	Musical Instrument Amplifier
Language	English

Summary

Safety Precautions

General Safety Guidelines

Essential precautions for safe operation, handling, and electrical safety.

Amplifier Overview and Layout

MARK IV Introduction

Introduction to the amplifier's design, heritage, and capabilities.

Front Panel Layout

Visual identification of all front panel controls and their locations.

Rear Panel Layout

Visual identification of all rear panel connections and switches.

Front Panel Controls

Power-Up Procedure

Step-by-step guide for safely powering on the amplifier.

Rhythm Mode Controls

Detailed explanation of controls for Rhythm 1 and Rhythm 2 channels.

Lead Mode Controls

Detailed explanation of controls for the Lead channel.

Master, EQ, and Power Controls

Explanation of Master Volume, Graphic EQ, Output Level, Standby, and Power modes.

Rear Panel Connections and Configuration

Power and Output Jacks

Details on AC receptacle, fuse, speaker jacks, and recording/slave outputs.

Switching and Connectivity

Explanation of effects loop, satellite connections, mode selector, and external jacks.

Power Amp Modes

Information on Triode/Pentode and Simul-Class/Class A power amp selections.

Tube Substitution

Guide for replacing and substituting power tubes.

Troubleshooting and Maintenance

Tube Noise and Microphonics

Diagnosing and resolving issues related to tube noise.

Power Tube Failures

Identifying and addressing problems with power tubes.

Pre-Amp Tube Issues

Diagnosing and resolving minor pre-amp tube noise problems.

Bias Adjustment Explained

Detailed explanation of bias adjustment concepts and procedures.