Rear Panel Operation - Marshall JVM2 Serie Mode D'emploi

Rear Panel Operation

SERIAL / PARALLEL FX LOOP (12)
The JVM is equipped with a series / parallel FX
loop. Connect your external FX equipment input
to the JVM SEND jack, and the FX output to the
JVM RETURN jack. As described previously,
this effects loop can be bypassed from the front
panel and the amount of effect can be dialed in
with the MIX control.
The +4dBu/-10dBV switch allows you to
configure the loop for its use with either
professional equipment (+4dBu setting) or with
guitar level effects like effects pedals (-10dBV
setting).
When MIX is set to WET all the signal goes
through the external loop, adding more direct
(unprocessed) signal as you turn it towards
DRY. This allows you to mix any amount of the
external effect without loosing or degrading the
direct signal quality.
When mixing the WET and DRY signals the
external effects processorʼ s output should be
configured to remove the direct (unprocessed)
signal or unpleasant phasing effects may occur
when mixing it again in the amplifier. If the
amplifier sounds thin after connecting an
external effect check that no direct signal is
being returned from the processorʼ s output.
Note that if the FX loop is ON and the MIX
control is set to WET without an external
processor connected, the amplifier will be
muted.
POWER AMP INSERT / SERIAL LOOP (13)
This is a passive loop connected right before the
master controls. It is a line level loop so it is
recommended to only use high headroom
devices to avoid signal degradation. Plugging
only into the return jack allows the use of the
JVMʼ s power section overriding the preamp.
Master controls and the emulated line out are
located after the serial loop so it is still possible
to take advantage of those features when using
an external preamplifier. The loop can be taken
off the circuit by pressing the BYPASS switch,
but as opposed to the Series / Parallel loop this
switch cannot be programmed.
EMULATED LINE OUT (14)
The pre master volume signal, processed
through a 4x12 speaker cabinet emulator and
electronically balanced is made available at this
connector.
FOOTSWITCH (15)
Connect the supplied footswitch using any
standard 1/4" jack mono lead. Using any other
type of footswitch rather than the supplied will
have no effect and will be ignored by the
amplifier.
MIDI In / Through (16)
Connect any external MIDI equipment to the
MIDI In DIN socket. A copy of the signal in this
connector will be available on the MIDI thru
socket to allow daisy chaining of MIDI
equipment. Note that the JVM only accepts
incoming data and it is not able to send any
MIDI commands.
SPEAKER Outputs (11)
There are 5 speaker outputs available on the
rear panel. They are labelled according to the
intended impedances:
16 Ohm: connect any 16 Ohms guitar cabinet to
this jack.
8 Ohm: connect a single 8 Ohms guitar cabinet
or two 16 Ohms guitar cabinets.
4 Ohm: connect a single 4 Ohms guitar cabinet
or two 8 Ohms guitar cabinets.
WARNING: Although the JVM amplifier has 5
speaker outputs, never attempt to connect more
speakers than rated. The safe combinations are
1x16 Ohm, 1x8 Ohm, 1x4 Ohm, 2x16 Ohm or
2x8 Ohm. Any other speaker configuration may
stress the power amplifier section and in
extreme cases may lead to valve and/or output
transformer failure.
HINTS & TIPS
Factory Reset
This will erase all the MIDI presets and set MIDI
reception channel to #1. Please note that once
the memory is erased it cannot be recovered.
Switch the amplifier off (power switch off, not
standby switch).
Press and hold CLEAN/CRUNCH CHANNEL
switch.
Switch the amplifier on (power switch on, not
standby switch).
The 2 channel LEDs will glow red.
Release the switch.
8