Marshall Amplification JVM 2 Stereo Amplifier User Manual


 
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Overview
I. Channels, Modes & Memory
Presenting the 2-channel, 100W and 50W
all-valve JVM amplifiers. Their 2 channels boast
3 modes, giving you a total of 6 different modes
to choose from - each with its own unique gain
structure. Even though their front panel contains
a total of 16 control knobs and 6 LED switches,
the JVM is simple to understand and operate
thanks to its extremely logical front and rear
panel layouts.
The front panel contains dedicated sets of
controls for each of their 2 channels -
CLEAN / CRUNCH and OVERDRIVE - plus
MASTER and REVERB sections. Each channel
contains the familiar controls, Volume, Bass,
Middle, Treble and Gain. The REVERB section
consists of 2 Reverb level controls, one for each
channel while the MASTER section is comprised
of 2 footswitchable Master Volumes, plus master
RESONANCE and PRESENCE controls that
work universally on both channels.
Each of the 2 channels has 3 switchable modes.
These are selected by the MODE switch
dedicated to each channel. To select a channel
press its respective MODE switch (or step on
the relevant button on the supplied 4-way
footswitch - see section II. Footswitch). To
scroll through the selected channel's 3 modes
keep pressing the said button and the colour of
the LED in the switch will change from green to
orange to red and then back to green. Doing this
steps-up the gain level each time (red being the
highest and green the lowest for each channel)
and changes the channel's tonal voicing to suit.
When you leave and then reselect a channel, it
will automatically recall the last active mode as
both channels remember the last mode they
were in until a change is made. For instance, if
you select the Overdrive channel's orange mode
and then go to the Clean channel, when you
reselect the Overdrive channel it will still be
orange.
In addition to channel and Mode selection, other
features switchable via the front panel and the
supplied 4-way footswitch are Reverb (on/off)
Master Volume selection (1 or 2), and
Series/Parallel effects loop (on/off). All 3 of
these options are also remembered by each
Mode.
To sum up, each of the JVMs 6 Modes will
remember its most recent Reverb, FX loop and
Master Volume selection. Additionally mode
setups can also be saved and recalled to one of
128 locations via MIDI.
II. Footswitch (UK patent pending)
The JVM come supplied with a 4-way
programmable footswitch which can be
connected to the amp via any standard guitar
cable.
*Please note that the supplied Footswitch lead is
unscreened and not suitable for guitar.
The 4-button footswitch features 5 LEDS
marked CLEAN / CRUNCH, OD, MASTER,
REVERB & FX. The LEDs for each of the 2
channels are 3-coloured Green, Orange and
Red, visually telling you which channel and
mode is selected alongside the status of Master,
Reverb and FX loop.
The footswitch enables you to assign any of its
4 switches to instantly recall any front panel
function (Switch Store Mode) or complete
channel setup (Preset Store Mode) in any order
and combination.
For example, you could program it so that:
Switch Store Mode
Any footswitch is assigned to act as any one of
your amp’s front panel switches:
Channel/Mode; Reverb on/off; Master Volume
1/2 and FX Loop on/off.
If a switch is assigned to select a particular
channel once is has been activated, it can be
used to scroll through the three modes, just like
its respective front panel switch.
Or…
Preset Store Mode
Each switch can be programmed to instantly call
up a combination of JVM button options to form
a Preset.
ENGLISH
ENGLISH
For example, you could program a mixture of
switching functions (in our example switches #1
and #2 work in Preset Store mode, and #3 plus
#4 work in Switch Store mode), so that:
Footswitch #1 = Overdrive channel, green mode
with Master Volume ‘1’, Reverb ‘on’ and FX loop
‘off’.
Footswitch #2 = Clean channel, red mode with
Master Volume ‘2’, Reverb ‘off’ and FX loop on.
Footswitch #3 = FX loop on/off
Footswitch #4 = Master 1/2
All the settings are stored within your footswitch;
this means it can be plugged into any JVM
amplifier and all your footswitch settings can be
instantly recalled.
Details on how to program your footswitch can
be found later in this manual.
III. Power Amp
The power amp stage of the JVMs is based on
the same as the one found in the JCM800 2203
and 1959 Superlead amplifiers and their 50W
cousins, responsible for the legendary Marshall
roar it has been adjusted to suit the variety of
tones found in the JVM. This section features
Presence and Resonance control to help shape
the overall tone of your JVM amplifier.
Your JVM is also equipped with a Silent
Recording mode. When the STANDBY switch is
OFF the power amplifier section is disabled but
the rest of the amplifier remains fully
operational.
IV. Studio Quality Reverb
The Marshall JVM is equipped with a studio
quality digital reverb routed in parallel to the
main signal and mixed by means of a valve.
When the reverb is engaged no degradation of
the direct signal occurs and when off it is
effectively removed from the circuit. Each of the
JVM’s channels also has its own dedicated
Reverb level control.
The Reverb switching has been designed to
avoid abrupt cut offs in the reverb tail so when
changing from channel to channel or switching
the reverb off, its tail naturally decays.
MODEL: PEDL-00045
4321