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Channel switching on an external
preamp using Relay 1 & 2
G-Major 2 has two built-in switching relays that
allow you to switch the channels of analog
preamps – either when changing presets or
when triggering this function by means of a
MIDI CC message coming from your MIDI
pedal. In other words:
• With each preset, you can decide whether
your preamp or combo should use the clean
or overdriven channel.
• Or you could switch the relays/preamp-
channels by sending a MIDI CC message to
G-Major 2 from your MIDI board.
Depending on the channel switching connection
on your preamp/combo, you must use either
• a “Y-Splitter” cable for splitting a stereo ¼"
jack to two mono jacks (tip-to-tip and tip-to-
ring) or
• a standard “Stereo jack to Stereo jack” cable.
– Relay 1 shorts the tip of the switching ¼" jack
with the sleeve/GND when set to “On”. “Off”
means that the relay is open.
– Relay 2 shorts the ring of the switching ¼"
jack with the sleeve/GND when set to “On”.
“Off” means that the relay is open.
Depending on the complexity of the
channel switching system on your
guitar amp, you may need to contact
the manufacturer of your guitar amp
and/or a technician to get soldering
advice for the optimum channel
switching setup. In the “Support”
section of www.tcelectronic.com, you
will find various channel switching
schematics for some of the most
common amplifiers on the market. If
you are not sure how to setup your
system, consult this section of our web
site first.
These parameters can be remotely controlled
via MIDI or using the SWITCH OUT jack on G-
Major 2. This is set up in the MOD menu.
You configure the Relays in the
Levels/Routing menu.
• Press the LEVELS/ROUTING key and select
Relay 1 or Relay 2 using the UP/DOWN
keys.
• Turn the ADJUST wheel to select
open/closed position.
Example
Let us assume you have hooked G-Major 2 up
with either a three-channel combo or preamp.
• First of all, check whether your amp uses two
mono connectors or one stereo connector for
channel switching. Use a matching cable.
• Connect the stereo jack of your cable to the
SWITCH OUT jack on G-Major 2 rear panel.
• Connect the two mono jacks (or the stereo
jack, depending on the cable used) to the
channel switching connectors on the combo
or preamp.
• Recall G-Major 2 preset that you want to use
for channel switching.
• Press the LEVELS/ROUTING key.
• Now select Relay 1 (“Rly1”) or Relay 2
(“Rly2”) using the UP/DOWN keys and use
the ADJUST wheel to open or close the two
relays.
By doing this, you are switching the channels
on your preamp. Exactly which setting will
activate the Clean, Crunch and Distorted
channels we can not tell as this varies from amp
RELAYS
TIP
RING
GND
GND
TIP
TIP
RING
GND
GND
RING
TIP
Y-Splitter
Cable
Stereo to Stereo
Jack Cable
