Mesa/Boogie Mark IV Amplifier manual Power Tube Substitution, Speaker Jacks

Page 17

REAR VIEW MKIV (Continued)

POWER TUBE SUBSTITUTION: (Continued)

ohm speaker should be plugged into the 4 ohm jack. However, please note that Mesa/Boogie cannot accept responsibility for any blown 6V6’s incurred during such usage! Proper operation depends totally on the correct setting of the aforementioned switches and this will be impossible to verify for warranty tube coverage. So please exercise caution when using 6V6’s! Incorrect setting of the switches won’t usually cause immediate tube failure, but the strain caused is far in excess of recommended ratings.

OUT

TRIODE SIMUL-CLASS HARMONICS

AMP

 

VOICING

POWER

 

 

LEAD

PENTODE

CLASS A

MID GAIN

SPEAKERS

 

 

8 OHM

4 OHM

4 OHM

 

RHY 2

RHY 1

LEAD

FT SW

EX SW

MODE SELECT

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CLASS A/ SIMUL FX LOOP

EQ

EXTERNAL SWITCHING JACKS

RHYTHM 1 RHYTHM 2

LEAD

 

 

 

 

 

 

These two outer tubes can be substituted with EL-34’s. CAUTION: Place amp in STANDBY mode when changing tubes.

CAUTION: Tubes can become very HOT...they can cause injury. Use care in removing tubes that are warm/hot and never remove a tube by pulling on the glass. Instead, grab the tubes socket or base and rock the tube from side to

WHT NG

44

TWH GN

44

WHT NG

44

WHT NG

44

454 STR

 

454 STR

 

454 STR

 

454 STR

 

GC 6L6

GC 6L6

GC 6L6

GC 6L6

NOTE:

SPEAKER JACKS:

side while pulling gently downward.

Speaker jacks for both 8 ohm and 4 ohm loads are provided. CAUTION: A speaker (or load resistor) must remain connected to a speaker output on your MARK IV to prevent damage to the power tubes and transformer! (For silent recording, merely pull the designated switch on the OUTPUT LEVEL control located on the Front Panel and do not disconnect the speaker.)

 

 

 

 

AMP

 

TRIODE SIMUL-CLASS

HARMONICS

5

 

2

 

 

 

VOICING

6

43

 

 

 

 

 

 

 

1

POWER

 

 

 

 

7

 

 

 

 

 

 

8

 

10

0

 

 

 

 

LEAD

9

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

PENTODE

CLASS A

MID GAIN

LEVEL

OUT

 

 

 

 

5

43

 

SPEAKERS

8 OHM

4 OHM

4 OHM

 

2

 

 

 

 

 

6

 

 

1

 

 

 

 

 

7

 

 

 

 

 

 

 

8

 

10

0

 

 

 

 

 

9

 

 

 

 

 

 

 

 

 

 

 

 

 

MODE SELECTOR SWITCH:

Two 4 ohm jacks are provided and should be used when you wish to run two 8 ohm speakers or cabinets. (This is because two 8 ohm loads connected in parallel present a combined load to the amplifier of 4 ohms.) Speaker mis-matching is not a cause for great concern - unless the combined load is considerably less than the rated impedance. If, for example, you run two 4 ohm cabinets - each plugged into a 4 ohm jack - the amplifier would “see” 2 ohms as the total load. And while this will not cause immediate damage, it will result in shortened power tube life. Mis-matching on the high side is always preferable, if you have no choice.

This switch determines the method of control over your MARK IV’S switching functions. The first position activates the footswitch. The next three positions select the individual modes manually.

SIMUL-CLASS HARMONICS

RHY 1

LEAD

 

 

VOICING

 

 

 

 

 

 

RHY 2

 

 

 

LEAD

 

 

 

EX SW

The last position enables the use of the EXTERNAL SWITCHING jacks. If ever the switching

 

 

 

 

 

FT SW

functions seem to operate incorrectly, always check that the MODE SELECTOR switch is set

CLASS A

MID GAIN

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

MODE SELECT

to the proper position.

 

 

 

 

 

 

 

 

 

4 OHM

 

4 OHM

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PAGE 13

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Image 17
Contents Mark Hello from the Tone Farm Mark IV Table of Contents USE Common Sense and Always Observe These Precautions Markk Front Panel Pull Bright Rhythm 1 GainRhythm 1 Treble R1 + R2 Bass & R1 + R2 MIDRhythm 2 Gain & FAT R1 PresenceR1 Master Rhythm 2 Treble Setting the Lead Mode Lead GainR2 Presence R2 MasterLead Treble Lead GainLead Bass & Lead MID Lead DriveGraphic EQ Lead BrightLead Presence & Lead Master Graphic EQ Silent Recording Pull SwitchOutput Level StandbyFuse ReceptacleInternal circuitry EQ Rocker Switch Reverb & Reverb FootswitchSatellite Control EQ & Send Jack Due to cable length or impedance mismatchingTriode / Pentode Switch Recording OUT when feeding a p.a. boardEffects Loop Section Recording OUTPower Tube Substitution SIMUL-CLASS / Class a SwitchHarmonics / MID Gain Switch Side while pulling gently downward Power Tube SubstitutionSpeaker Jacks Going Stereo External Switching JacksMark Mark IV Personal Settings Power Tube Substitution Tube Noise Diagnosing Power Tube FailuresTube Noise & Microphonics Diagnosing PRE-AMP Tube Problems Here’s a question we often hear Bias Adjustment Cheers Randall Smith Designer & President Front View Mark Mesa Boogie 707 778-6565 FAX no

Mark IV Amplifier specifications

The Mesa/Boogie Mark IV amplifier stands as a landmark in the world of guitar amplification, boasting a rich history that intertwines with the evolution of rock music. Launched in the 1990s, the Mark IV embodies the hallmark traits of Mesa/Boogie’s innovative spirit, delivering versatility, power, and an extensive range of tonal options.

At the core of the Mark IV is its three-channel configuration, which includes Clean, Rhythm, and Lead channels. Each channel offers varying degrees of distortion and gain that can be tailored to the player's distinct preferences. The Clean channel produces a pristine sound, ideal for jazz or blues, while the Rhythm channel steps up with a compelling crunch for rock tones. The Lead channel takes it further, providing a high-gain saturation, perfect for heavier genres. The ability to switch seamlessly between these channels enables musicians to transition effortlessly during performances.

One notable feature of the Mark IV is the onboard graphic equalizer. This 5-band EQ allows guitarists to sculpt their sound intricately, enhancing or attenuating frequencies to achieve a desired tone. Coupled with its patent-pending Gain structure, the amp provides an unparalleled range of tonal shaping ability, making it a favorite among professionals and hobbyists alike.

The Mark IV also benefits from the innovative Dyna-Watt technology. This feature ensures that players can harness full power from the amp, regardless of volume levels. Dyna-Watt adjusts the output stage to produce dynamic responsiveness, allowing for a richness of sound that stands out without needing excessive volume. This feature is particularly useful for studio recording and smaller venues, where loud amplification can be an issue.

Mesa/Boogie amplifiers are renowned for their build quality, and the Mark IV is no exception. Crafted with precision, it features a rugged chassis and high-quality components designed to withstand the rigors of touring. The amp’s tube-driven design, utilizing powerful 6L6 or EL34 tubes, contributes to its warm tone and dynamic response, appealing to a wide array of musicians.

In conclusion, the Mesa/Boogie Mark IV amplifier is a cornerstone piece of gear for guitarists seeking a powerful, versatile, and richly infused tonal experience. With its three-channel architecture, graphic equalizer, Dyna-Watt technology, and robust construction, it meets and exceeds the demands of contemporary musicians across genres. Whether on stage or in the studio, the Mark IV remains a potent tool for expression, earning its place in the pantheon of iconic amplifiers.