Glab M4L User manual
Instrukcja obsługi
User Manual
Bedienungsanleitung
Midi 4 x Loop
M4L
4
1
Version 1.0
Table of contents
Structure ___________________________________________________ 2
Scheme and signal path description ____________________________ 4
Manual loops switching_______________________________________ 4
MIDI channel setting _________________________________________ 4
Controlling via MIDI commands ________________________________ 4
DS1 micro switch ____________________________________________ 6
DS2 micro switch ____________________________________________ 6
Power supply _______________________________________________ 6
Parameters _________________________________________________ 7
Possible using of the M4L_____________________________________ 7
MIDI implementation chart ____________________________________ 9
EMC/EMI & Certificate of conformity ___________________________ 11
2
Dear Customer,
Congratulations for choosing our G LAB product!
MIDI 4 x LOOP (M4L) is a loops’ switcher controlled by MIDI interface
(by Program Change or Control Change commands) or manually, by using
the buttons. Using the MIDI commands it is also possible to mute the signal
(e.g. for silent tuning). M4L can be controlled by every MIDI controller and it
is particularly recommended as an extension of the G LAB guitar system
controllers GSC.
Basic characteristics:
- four bypassed (by electro mechanic relay) loops to connect the pedal
effects or serially connected sets of effects,
- muting circuit based on opto elements,
- MIDI THRU connector to connect other MIDI devices,
- power supply and active loop indicators,
- four buttons for loops’ manual on/off switching,
- power supply 9V DC (direct current).
Structure
1 - Signal output connector 13 - Signal input connector
2 - LOOP 4 signal input (RETURN) 14 - MIDI input
3 - Power supply connector 15 - MIDI copy (THRU)
4 - LOOP 4 signal output (SEND) 16 - Loop 4 status indicator
5 - LOOP 3 signal input (RETURN) 17 - Loop 4 on/off button
6 - MIDI channel settings switcher 18 - Loop 3 status indicator
7 - LOOP 3 signal output (SEND) 19 - Loop 3 on/off button
8 - LOOP 2 signal input (RETURN) 20 - Loop 2 on/off button
9 - LOOP 2 signal output (SEND) 21 - Loop 2 status indicator
10 - DS1 and DS2 micro switch 22 - Loop 1 on/off button
11 - LOOP 1 signal input (RETURN) 23 - Loop 1 status indicator
12 - LOOP 1 signal output (SEND) 24 - Power supply indicator
3
4
Scheme and signal path description
M4L has true passive signal path (without signal boosting and buffering
elements). Due to this the M4L doesn’t influence the guitar tone (doesn’t
change the tone and doesn’t cut the signal). It is recommended to use the
M4L to “exclude” from the effects’ signal path the effects without true bypass
function. Controlling by MIDI provide galvanic separation from controlling
device. Every time after switching on the power supply four effect loops are
switched off and the signal path is “opened”.
Manual loops switching
For manual loops switching there are used four buttons signed LOOP1,
LOOP2, LOOP3 and LOOP4. To switch on/off the loop press corresponding
button.
MIDI channel setting
To set the MIDI channel use the rotatable knob signed as MIDI
CHANNEL. To switch the channel use the small screwdriver to turn smoothly
central part of the switcher to the right or to the left. The arrow-head indicates
set channel (letter A, B, C, D, E, F correspond successively with the channel
numbers 10, 11, 12, 13, 14, 15, and number 0 indicates channel 16).
Controlling via MIDI commands
M4L can by controlled by Program Change commands. The table below
shows the Program Change command functionality.
LOOP
PROG. CH. 12
MUTE
1X OFF OFF OFF
2X ON OFF OFF
3X OFF ON OFF
4X ON ON OFF
5
LOOP
PROG. CH. 34
MUTE
X1 OFF OFF OFF
X2 ON OFF OFF
X3 OFF ON OFF
X4 ON ON OFF
LOOP
PROG. CH. 1234 MUTE
100 ON ON ON ON ON
101 RESTORE OFF
X – every value from 0 to 9 range
The units’ digit of program number defines the state of LOOP3 and LOOP4,
the decimal digit of program number defines the state of LOOP1 and LOOP2.
Receiving of the command which units’ digit or decimal digit has out of range
value causes ignoring that digit(s) and considering the digit with correct value.
M4L can be controlled by individual Control Change type command or
individual controllers of particular functions. The table below shows the
Control Change commands functionality.
CONTROL CHANGE
NUMBER VALUE
0 - 63 LOOP1 OFF
80 64 - 127 LOOP1 ON
0 - 63 LOOP2 OFF
81 64 - 127 LOOP2 ON
0 - 63 LOOP3 OFF
82 64 - 127 LOOP3 ON
0 - 63 LOOP4 OFF
83 64 - 127 LOOP4 ON
0MUTEON
71-127 MUTE OFF
CONTROL CHANGE LOOP
NUMBER VALUE 12
MUTE
1X OFF OFF OFF
2X ON OFF OFF
3X OFF ON OFF
89
4X ON ON OFF
6
CONTROL CHANGE LOOP
NUMBER VALUE 34
MUTE
X1 OFF OFF OFF
X2 ON OFF OFF
X3 OFF ON OFF
89
X4 ON ON OFF
X – every value from 0 to 9 range
CONTROL CHANGE LOOP
NUMBER VALUE 1234MUTE
100 ON ON ON ON ON
89 101 RESTORE OFF
DS1 micro switch
DS1 micro switch connects controlling circuit ground to main signal
ground. If the M4L’s 9V power supply circuit is fully separated from ground
(isn’t connected with any ground) the DS1 switch should be switched to ON
position.
DS2 micro switch
DS2 micro switch enables/disables the silent switching function. In order
to activate the function that mutes the loops switching clicks the DS2 switch
should be switched to ON position. The DS2 switch should be switched to
OFF position when in the signal path after the M4L there is another device
muting the switching clicks.
Power supply
M4L should be supplied from 9V (DC) external adaptor (efficiency 100 mA
or more). Before plugging the power supply check the pin polarisation. M4L is
protected against opposite polarity (minus as center).
If this protection switches on it is needed to disconnect the power supply and
wait few minutes before reactivation of the device.
ATTANTION!: Damage of the M4L caused by improper power supply causes
the loss of the warranty.
7
Parameters
Dimensions (depth x width x height) 270 x 70 x 38 mm
Weight 620 g
Maximal input signal 30 dBu
Power supply 9V DC (8,7 to 9,4V)
Power consumption 0,1 A
Possible using of the M4L
Below are shown the possible schemes of M4L connection with the guitar
system.
Scheme of M4L connection to the amp’s effects loop
8
Scheme of adding four effects loops to the GSC controller
Scheme of the system with the M4L connected to the amp input and the GSC
in the effects loop
Table of contents
