Little Lehle II
Operating instructions
www.lehle.com
Lehle GmbH • Grenzstr. 153 • D-46562 Voerde • Germany • Tel +49 (0) 2855 850070
Dear Musician!
Thank you for purchasing the Little Lehle II!
I have been building units that switch, split and route signals with
no technical compromises and with maximum musical fidelity since
1999. Your new Little Lehle II comprises only the very best compo-
nents.
Every assembly of your Little Lehle II has been made and tested in
Germany.
Your Little Lehle II is of extremely robust design and construction,
to make sure that you get absolutely years and years of enjoyment
from it. If you should nonetheless have a problem, or simply a question, just mail me or a member of the Lehle team at:
support@lehle.com
I wish you the very greatest pleasure and success using your
Little Lehle II!
Burkhard Georg Lehle
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Contents
Introduction ............................................................................................................................... 2
Technical data ........................................................................................................................... 3
General description ................................................................................................................... 4
Typical uses
- Little Lehle II as an effects loop switcher .......................................................................... 8
- Little Lehle II as an effects loop switcher for Inserts between Send and Return of an amplifier .. 9
- Little Lehle II as an A/B switcher between two amplifiers ................................................ 10
- Little Lehle II as an A/B switcher between two instruments .............................................. 12
- Little Lehle II as a tuner-mute switcher ...........................................................................13
- Little Lehle II as an effects loop switcher for microphones ............................................... 14
Troubleshooting ....................................................................................................................... 15
Little Lehle II signal flow diagram .......................................................................................... 18
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The Little Lehle II - the universal Lehle switching and looping tool.
The Little Lehle II removes effects pedals from
the signal path at the press of its button. A signal
can be picked off at any point in the signal chain,
to switch to an instrument tuner, for example.
The Little Lehle II can also be used to switch between two instruments on one amp or, vice versa,
between two amps with one instrument. Extremely
diverse sound sources are possible - signals from
pickups, microphones and keyboard line-out
sockets are routed loss-free to the target amplifier or recorders, and all jack plugs are stereo.
Switches with gold-plated contacts assure True
Bypass. As on this unit’s “big brother”, the Lehle
D.Loop SGoS, not only the stereo signal, but also
the signal ground, is switched – so hum loops just
can’t happen any more when switching between
two amps or looping effects.
The easy-action mushroom-shaped button characteristic of Lehle products is mounted in the cover,
so that your foot pressure is transmitted indirectly,
via only a spring, to the slide switch with its gold-
plated contacts. The printed circuit board with the
electronics on it is thus not exposed to mechanical
loads, making the Little Lehle II virtually indestructible and guaranteeing years of trouble-free
switching.
Technical data
Weight: 360 g
Length: 9 cm (3.5”)
Width: 9.2 cm (3.6”)
Overall height: 5 cm (2”)
Voltage range: 8 - 20V DC or AC
Max. power take-up: 20 mA
Max. level: 36 dBU (40 mA)
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4
General description
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1. Input socket
Connect your instrument to this socket.
The input signal enters via this socket. Like all the
jack plugs on the Little Lehle II, the socket is
of stereo type. The Little Lehle II thus switches
stereo signals (such as stereo effects or keyboards)
and balanced signals (like those from microphones, for instance) and, of course, simple mono
signals, like that of an electric guitar.
The LED (6) shows green when the signal is present on the output (4) together with the ground
(earth) connection. Press the True Bypass switch
(7) and the stereo signal and ground connection
are routed to the S socket (2). The LED (6) will now
show red. Switching of the ground connections
eliminates the possibility of hum loops.
2. Send socket
Connect the input of your effects unit or amplifier
to this socket.
Depending on the mode selected, this socket is
either connected to the input of one or more effects units, to a second amplifier or, for example,
to a tuner.
3. Return socket
Connect the output of your effects unit or a
second instrument to this socket.
This socket can be used for connection to the
output of an effects unit, to the last output of a
complete effect chain or, for example, can also be
used for a second instrument. It has no function
if the Little Lehle II is used as an A/B box for
operation with two amplifiers.
4. Output socket
Connect your amplifier to this socket.
The output signal is routed out of the Little Lehle
II via this socket. The LED (6) shows green when
the input signal together with the ground connection is directly present here. Pressing the True
Bypass switch (7) routes the R(eturn) socket signal
(3) together with the ground connection to the
output socket.
5. External power supply
Connect a power pack for a voltage of 8 to 20 V
to this socket, when needed.
The Little Lehle II switches all audio signals
completely without electricity. To detect the switch-
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ing status, it requires an 8 to 20V power supply for
operation of the LEDs. Polarity is of no importance. The supply voltage is internally rectified
and stabilized in order to guarantee trouble-free
operation. A thermal cut-out automatically trips
and switches the unit off if a short circuit occurs.
A correctly fitting plug connector for the powersupply socket is supplied with the Little Lehle II.
This can be soldered to the required power unit if
necessary. It is advisable to use a separate power
adapter or an outlet on a multiple outlet power
adapter with electrically isolated outlets for the
Little Lehle II, but with no other loads connected
to it, to avoid interference noise during operation
or when switching.
6. LEDs for switching status
If the LED shows green, the Input (1) is directly
connected to the Output (4).
The high-intensity LEDs clearly indicate the current
switching status - even under bright spotlights.
When you use the Little Lehle II as an effects
loop switcher and the LED shows green, the effects
are in Bypass, when red they are in the signal
path.
7. True Bypass switch
Here you can switch.
Two parallel slide switches with gold-plated contacts, which switch the stereo signal together with
the ground connections, are actuated inside the
switcher by means of a practically indestructible
switching mechanism. The slide switches switch
virtually silently, since they function completely
bounce-free. Do you hear nevertheless unpleasant
sounds like a loud cracking while switching, please
read chapter “Troubleshooting” on page 15.
8. Base and fixing
You can use the fixing screws supplied with the
Little Lehle II to fix it to a base plate (or a pedal
board, for example).
Tip: in case you prefer a velcro solution for your
pedalboard we recommend to write down the
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serial number of the pedal before covering it for
eventual support matters.
Thanks to its ready-to-go fixing system, the Little
Lehle II can be mounted without difficulty on
a base plate. To do this, undo the four housing
screws and detach the cover. Then fix the device
base to a base plate using the two screws, the
washers and the spacers supplied. Replace the
cover and tighten the four housing screws - done!
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Typical uses
The Little Lehle II as an effects loop switcher
You can use the Little Lehle II as a loop switcher
for individual effects units, and also for complete
pedal boards. Not all effects pedals feature True
Bypass, and those that don’t can cause signal losses when deactivated. The Little Lehle II makes
it possible to eliminate them from the signal path
completely in just one step.
9
What to do:
1. Connect your instrument to the Input socket (1)
of the Little Lehle II.
2. Connect the input of the effects unit with the
Send (2) of the Little Lehle II.
3. Connect the output socket of the effects unit
with the Return socket (3) of the Little Lehle II.
4. Connect the amplifier with the Output socket
(4).
5. There you go!
Note:
This works equally well with both mono and stereo
effects. If you are using stereo effects via a mono
input, make sure that all the jack plugs connected
to the Little Lehle II are stereo. Where a mono
signal is present, the mono-signal conductor must
be soldered to both the tip and the ring of the
plug, since the signal on the ring of the jack plug
would be muted by a mono jack plug.
The Little Lehle II as an effects loop switcher
for Inserts between Send and Return of an
amplifier
The Little Lehle II can also be excellently used
in FX loops of amplifiers to loop in 19”-effects or
even pedals. Low-impedance signals with high
level the Little Lehle II easily switches without
loss of signal.
Device connection
Input (1) Instrument
Send (2) Input effects unit(s)
Return (3) Output effects unit(s)
Output (4) Amp
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What to do:
1. Connect the Send of your amplifier to the Input
socket (1) of the Little Lehle II.
2. Connect the input of the effects unit with the
Send socket (2) of the Little Lehle II.
3. Connect the output socket of the effects unit
with the Return socket (3) of the Little Lehle II.
4. Connect the Return of your amplifier with the
Output socket (4).
5. There you go!
The Little Lehle II as an A/B switcher between two amplifiers
The Little Lehle II can be extremely useful for
switching, when playing live with two amps, for
instance, between the clean sound of amp A and
the distorted sound of amp B. It also enables you
to switch quickly between familiar sounds, or to
Device connection
Input (1) Amp Send
Send (2) Input effects unit(s)
Return (3) Output effects unit(s)
Output (4) Amp Return
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compare A and B, when you are in the studio or
the rehearsal room.
What to do:
1. Connect your instrument to the Input socket (1)
of the Little Lehle II.
2. Connect the first amplifier to the Send socket (2)
of the Little Lehle II.
3. Do not use socket R (3).
4. Connect the second amplifier to the Output
socket (4) of the Little Lehle II.
5. There you go!
Note:
Most amplifiers are connected to a power supply using a three-core cable: two cores supply
the power, while the third core is the equipment
grounding conductor which grounds the amplifier.
If this ground core is installed, it must, for safety
reasons, never be removed, taped off or disconnected! Because of the grounding and the signal
ground of the guitar, two amplifiers connected to
one guitar can generate background noise. This
background noise is called “ground loop”. You are
guaranteed not to have ground loops when you
use the Little Lehle II, because it switches not
only the signal back and forth between the amplifiers, but also, simultaneously, the signal ground.
Device connection
Input (1) Instrument
Send (2) Amp 1
Return (3) -
Output (4) Amp 2
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The Little Lehle II as an A/B switcher between
two instruments
In order to swap between two instruments quickly
and easily, you can install the Little Lehle II between the instruments and the rest of your setup. It
is not always possible to mute your amplifier or PA
channel, and just pulling out the plug can cause
nasty popping from the speakers. To do it in just
one step:
What to do:
1. Connect your first instrument to the Input socket
(1) of the Little Lehle II.
2. Do not use socket S (2).
3. Connect your second instrument to the Return
socket (3) of the Little Lehle II.
4. Connect the amplifier to the Output socket (4)
of the Little Lehle II.
5. There you go!
Device connection
Input (1) Instrument 1
Send (2) -
Return (3) Instrument 2
Output (4) Amp
13
The Little Lehle II as a tuner-mute switcher
Even in smaller setups with only one guitar and
one amplifier, the Little Lehle II can help by
muting the signal while you are tuning up, so that
your audience and your bandmates do not hear
you.
What to do:
1. Connect your instrument to the Input socket (1)
of the Little Lehle II.
2. Connect your tuner to the Send socket (2) of the
Little Lehle II.
3. Do not use the R socket (3).
4. Connect your amplifier to the Output socket (4)
of the Little Lehle II.
5. There you go!
Device connection
Input (1) Instrument
Send (2) Tuner
Return (3) -
Output (4) Amp
14
The Little Lehle II as an effects loop switcher
for microphones
More and more vocalists are using effects units to
modify the sound of their voices. The Little Lehle II
is optimally suitable for this function, too, since it can
also switch balanced signals. It does not have to be
a microphone, of course - the Little Lehle II also
switches other balanced signal sources.
What to do:
1. Connect your microphone to the Input socket
(1) of the Little Lehle II.
2. Connect the input of the effects unit to the Send
socket (2) of the Little Lehle II.
3. Connect the output of the effects unit to the
Return socket (3) of the Little Lehle II.
4. Connect the input of your mixer to the Output
socket (4) of the Little Lehle II.
5. There you go!
Balanced signal lines are fitted with XLR
connectors or TRS (Tip Ring Sleeve) jack plugs. In a
balanced signal line, the signal is present in phase
at the tip, as in the case of an unbalanced signal
line (XLR Pin 2). The second signal conductor
carries the same signal, but with the opposite
polarity or mirror-image phase (Ring, XLR Pin 3).
Device connection
Input (1) Microphone (balanced)
Send (2) Input effects unit (balanced)
Return (3) Output effects unit (balanced)
Output (4) Input mixer (balanced)
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The third conductor is the screening, and again
constitutes the signal ground (Sleeve, XLR Pin 1).
Note:
Signals from microphones that require phantom
power cannot be switched this way, since this would
mean that the phantom power would be switched
off and on. Switching phantom power off and on
generally causes a loud noise!
Troubleshooting
Something is rattling inside my unit
If you should happen to shake the Little Lehle II,
you will hear a slight metallic rattling from inside.
This is a mechanical noise caused by a flat spring
which diverts the force of the True Bypass switch
button on to the horizontal slide switch inside
the Little Lehle II. So it is not a defect, not a
problem, just a healthy indication that the spring is
not jammed.
Audible clicking during switching
Two things, generally, can cause switching noise:
the power supply unit used, or a DC voltage
component in the audio signal, a so-called “DC
offset”.
The first thing to do, in order to determine whether
the switching noise is caused by the Little Lehle II
itself, is to remove all other factors, if possible, from
the signal path. To do this, remove the Little Lehle
II’s power supply (5), then connect the instrument
to the input (1) and the amplifier to the output (4)
of the Little Lehle II. Use a patch cable and plug
it into the Send (2) and the Return socket (3), Send
Jack XLR
Ground Sleeve Pin 1
Signal in mirrored phase Ring Pin 3
Signal in phase Tip Pin 2
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and Return are now bridged. The switching noise
should now be significantly less, or have disappeared completely; if not, test out other instruments
and/or other amplifier combinations. If, contrary
to expectations, the switching noise does not
disappear, then please contact our support team at
support@lehle.com.
Power supply unit
Switching noise is frequently the result of using
non-electrically isolated or severely interferencegenerating digital / switched-mode power supply
units. The only solution here is to use a better
power supply unit.
DC offset
So-called DC offset, i.e., a DC voltage component
in the audio signal, is a frequent problem, and
causes loud switching noises which are heard as
popping or clicking. The Lehle DC Filter is useful
in filtering out this DC voltage from the signal,
and should be connected as shown in the following example.
Filtering of the DC voltage component at
the output of an effects unit
The Lehle DC Filter can be used behind the output of the final effects unit to minimize switching
noise if you use one or more effects units in the
signal path with an effects loop switcher.
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What to do:
1. Connect the output of the effects unit to the DC
socket of the Lehle DC Filter.
2. Connect the 0DC socket of the Lehle DC Filter
to the return of the effects loop switcher.
3. There you go!
Filtering the DC voltage component at the
input of an amp
Many amplifiers, and older models, in particular including the appreciated vintage amps, of course
- also feature DC voltage at the input, which can
become noticeable in the form of an unpleasant switching noise. The Lehle DC Filter also
provides a remedy here!
What to do:
1. Connect the DC socket of the Lehle DC Filter
to the input of the amplifier.
2. Connect the output of the amp switcher to the
0DC socket of the Lehle DC Filter.
3. There you go!
Device connection
DC socket Output effects unit(s)
0DC socket Return effects loop switcher
Device connection
DC socket Input amp
0DC socket Output amp switcher
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Little Lehle II signal flow diagram
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