Owner`s manual

You can think of the PRESENCE as a control that allows you to either clamp the power amp down, compressing it and darkening things,
or open it up and let the full spectrum of upper harmonics come blazing through. It also has a great deal to do with how dynamic the
signal is and how a sound will cut through the mix in an ensemble environment.
At low settings (7:30–10:30) the sound will be warm and round with a more compressed feel and dynamic fluctuation will be somewhat
limited. As the PRESENCE is increased (11:00–2:30), the top end starts to become more dominant and the compression gives way
to “cut” and dynamic peaks jump out with startling speed and accuracy. At the top end of the control (2:30–5:30), a super aggressive
blend of upper harmonics dominate the sound and this region can be somewhat dangerous if it’s not applied in small measures. Higher
notes will slice and dice even the bravest of ears and we suggest using this region mostly in the studio for recording heavy crunch
rhythm parts and even then, mostly on parts that feature the lower strings. This region, especially when coupled with the inherent
curve of many of the microphones typically used in P.A. (sound reinforcement) applications, can be truly punishing.
We suggest using the lower to middle range of the PRESENCE (9:00–12:30) for the best (most balanced) sound in all of the Modes
and venturing outside this only for specific applications... perhaps where you need real extremes... like an aggressive top-end peak
or a really dark, highly-compressed sound.
Clean sounds in Channel 1 can often benefit from a bit higher settings (10:30–12:00) than sounds that have overdrive involved in their
makeup. Once saturation begins, the frequencies carried in the PRESENCE control can make things edgy or brittle… even buzzy, real
fast if you aren’t careful. Overdriven chording sounds can tolerate higher settings (10:30–12:30) better than can single note sounds,
which usually want to roam the zone below 11:00 to stay round, focused and vocal.
NOTE: The XTREME Mode in Channel 2 radically re-voices the negative feedback in the power section and inherently contains much
more of this upper harmonic region than any of the other Modes. This increase in top-end cut and aggression renders the PRESENCE
control less active than in the other Modes because there is so little negative feedback for the PRESENCE to work on and so much
“bite” there already in the XTREME Mode’s character.
NOTE: Repeated Here For Awareness; High settings of the PRESENCE (2:30–5:30) can put extra stress on even borderline microphonic
preamp tubes (ones that are susceptible to high pitched ringing and noise) and cause them to begin ringing or show other signs of
instability. Many tests were run on the set of tubes that shipped in your MARK FIVE: 25 to ensure they were stable at the time of con-
struction. However, tubes are not perfect devices—much like light bulbs—and can change over time and become more microphonic.
Luckily you can remedy most tube problems with a simple tube swap. Avoiding extremely high PRESENCE settings can be one way
of decreasing the likelihood of encountering these annoying microphonic tube problems.
MASTER
This control determines the overall output (volume) level of each Channel and is located at the very end of the preamp.
By using it in combination with the GAIN control, any amount of preamp signal strength (within a Modes’ parameters) can be achieved
at any playing volume. Once you have dedicated the Channels to their respective sounds with the Modes and Controls,
you can then balance the volume levels of the Channels using the MASTER controls.
The MASTER controls also serve as the FX Loop SEND Level controls and determine the output signal strength at the
Rear Panel SEND jack. Balance the preamp Channels signal strength at the SEND with the MASTER Controls as well,
keeping in mind that clean sounds are more dynamic and produce quicker dynamic peaks than more compressed high
gain sounds. So use your ears as well as any INPUT LEDs on your processors for balancing SEND Levels, as the lights may not tell
the whole story. If you don’t hear any clipping on your clean sounds, the levels are likely fine even though the LEDs may show more
signal strength in on the clean sounds.
For general applications and to get the best performance out of all the Modes we recommend MASTER settings in the 9:00–12:00
range with most people settling in around 10:30 or so for average playing volumes.
Some purists like to run the MASTER all the way up and raise the GAIN until they reach their desired sound—thinking that this
achieves the purest sound. In theory, they believe this resembles removing the control altogether from the signal path, and in a way
it does. However, most all the vintage “non-master” amplifiers they are seeking to emulate have resistors in that place in the circuit
anyway to adjust or “tune” the output of the preamp to the power section sensitivity.
PAGE 21
CLEAN
CRUNCH
FS
MK IIC+
MK
IV
XTREME
GAIN TREBLE
MID BOOST
MID PRESENCE
MASTER
BASS
EQ ON
EQ
O
O
EQ FS
SPKR
ON
CLOSED
BACK
OPEN
BACK
CabClone™
D.I.
SPKR
OFF
LIFT
GROUND
EQ ON
EQ FS
CAUTION: Unplug
power before
servicing
120 V~
60 Hz
1 A
1.25 A
SLO
BLO
AMPLIFIER
44YV
HEADPHONERETURNSEND
4 OHM 8 OHM
4 OHM
REVERB
CH 2 CH 1
MARK FIVE: 25™
VACUUM TUBE
AMPLIFIER
HANDCRAFTED
IN PETALUMA,
CALIFORNIA
80Hz 240 750 2200 6600
25 W
10 W
25 W
10 W
TUBE GUIDE
6 x 12AX7
2 x EL 84
PATENTED
7,602,927
(USE WITH TWO 8 OHM SPKRS)
FX
SPEAKERS
INPUT
FT SW
POWER
STANDBY
MARK
5
TWENTY-FIVE
™