Lehle LITTLE LEHLE III User manual

OPERATING INSTRUCTIONS
LITTLE LEHLE III

LEHLE GmbH · Germany · www.lehle.com · [e-mail]
Dear Musician!
Thank you for purchasing the
LITTLE LEHLE III!
I have been building units that switch,
split and route signals with no technical
compromises and with maximum musi-
cal fidelity since 1999. Your new LITTLE
LEHLE III comprises only the very best
components.
Every assembly of your LITTLE LEHLE III
has been made and tested in Germany.
Your LITTLE LEHLE III is of extremely ro-
bust 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:
[e-mail]
I wish you the very greatest pleasure and
success using your LITTLE LEHLE III!

LEHLE GmbH · Germany · www.lehle.com · [e-mail]
CONTENT
Introduction
Technical data
General description
Selecting the operating mode and foot switch mode
Typical uses of the LITTLE LEHLE III as
an eects loop switcher
an eects loop switcher for inserts between send and return of an amplifier
an A/B switcher between two amplifiers
as an A/B switcher between two instruments
a tuner-mute switcher
an eects loop switcher for microphones
LITTLE LEHLE III signal flow diagram
4
6
7
11
12
13
14
15
16
17
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LEHLE GmbH · Germany · www.lehle.com · [e-mail]
The LITTLE LEHLE III - The universal Lehle
switching and looping tool.
The LITTLE LEHLE III allows you to remove
eects pedals from your signal path at
the press of a button.
A signal can be picked o at any point
in the signal chain - for example, allow-
ing you to switch to an instrument tuner.
The LITTLE LEHLE III can also be used to
switch between two instruments with one
amp or, vice versa, between two amps
with one instrument.
Extremely diverse sound sources are no
problem. Signals from pickups, micro-
phones and keyboard line-out sockets
are routed loss-free to a target amplifier
or recorder.
All jack sockets are stereo, so you can re-
route balanced signals too.
With the release of the LITTLE LEHLE III
you can now combine mono and stereo
signals. This will allow you to integrate
an eects pedal with a mono input and
stereo output into the signal path of the
LITTLE LEHLE III without limitations.
The LEHLE-Switch works with a micro-
controller and an intelligent true bypass
relay circuit with an active pop suppres-
sion function, thereby allowing the LITTLE
LEHLE III to switch even faster than me-
chanical switches, noise-free and without
wear.
The easy-action mushroom-shaped but-
ton characteristic of LEHLE products is
mounted in the cover so that your foot
pressure is transmitted indirectly via a
spring. Thus the circuit board is not ex-
posed to mechanical loads, making the
LITTLE LEHLE III virtually indestructible
and guaranteeing years of trouble-free
switching.
Not only is the stereo signal switched, but
also the earth, - so say ‘goodbye’ to hum
when switching between two amps, and
selecting eects loops - it just can’t hap-
pen anymore.
New for the LITTLE LEHLE III are the three
operating modes, making the switch work
as either a latching or momentary switch,
allowing for short or rhythmic stutter-ef-
fects.
INTRODUCTION

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LEHLE GmbH · Germany · www.lehle.com · [e-mail]
The third mode combines a mixture of
operating mode one and two: a short
press engages the latching function and
a long press is momentary. These three
modes can be operated with or without
pop suppression.
Think of the creative potential.
We take care of your signal so that you
can take care of the music.

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LEHLE GmbH · Germany · www.lehle.com · [e-mail]
TECHNICAL DATA
Weight 350 g
3.55“
3.8“
1.85“
9-15 V DC
70 mA
+30 dBu
Length
Width
Overall height
Supply voltage
Current consumption
Max level

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LEHLE GmbH · Germany · www.lehle.com · [e-mail]
GENERAL DESCRIPTION
S
R
LITTLE LEHLE
MADE IN GERMANY
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 III,
the socket is of stereo type.
The LITTLE LEHLE III thus switches stereo
signals (such as stereo eects or key-
boards) and balanced signals (like those
from microphones, for instance) and, of
course, simple mono signals, like that of
an electric guitar.
The LED (7) shows white when the signal
is present on the output (5) together with
the ground (earth) connection.
Press the True-Bypass switch (9) and the
stereo signal and ground connection are
routed to the S socket (3). The LED will
now show blue.
Switching of the ground connections
eliminates the possibility of hum loops.
1
23456
7
8 9

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LEHLE GmbH · Germany · www.lehle.com · [e-mail]
2. MONO-TO-STEREO SWITCH
Activates at the input socket the mono-to-
stereo function.
If this switch is not pressed, the LITTLE
LEHLE III works with either mono or stereo
signals. This means, all sockets should be
occupied with either mono jacks (TS) or
stereo jacks (TRS). By doing this you can
place a mono or stereo eects pedal in
the loop of the LITTLE LEHLE III.
Some eects oer a stereo output, but a
mono input. If the mono-to-stereo switch
is pressed, the input (1) and send (3) can
be occupied with mono jacks (TS), while
the return (4) and output (5) transfer a
stereo signal via stereo jacks (TRS).
If the LITTLE LEHLE III is activated the in-
put signal will be sent in mono to the ef-
fects pedal. The output of the eect can
be returned in stereo to the return (4) and
sent out to the output (5) in stereo. If the
LITTLE LEHLE III is deactivated the mono
signal will be split straight after the input
and sent loss-free to the output (5).
3. SEND SOCKET
Connect the input of your eects unit or
amplifier to this socket.
Depending on the application, this socket
is either connected to the input of one or
more eects units, to a second amplifier
or, for example, to a tuner.
4. RETURN SOCKET
Connect the output of your eects unit or
a second instrument to this socket.
This socket can be used for connection
to the output of an eects unit, to the last
output of a complete eects chain or, for
example, can also be used for a second
instrument. It has no function if the LITTLE
LEHLE III is used as an A/B box for opera-
tion with two amplifiers.
5. OUTPUT SOCKET
Connect your amplifier to this socket.
The output signal is routed out of the LIT-
TLE LEHLE III via this socket. The LED (7)
shows white when the input signal togeth-
er with the ground connection is directly
present here. Pressing the foot switch (9)
routes the R(eturn) socket signal (4) to-
gether with the ground connection to the
output socket.
S
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If you are using the output socket to
send a stereo signal to two amplifiers, a
ground loop occurs which can cause hum
and noise. We recommend galvanically
isolating one amplifier by using the LEHLE
LITTLE DUAL II or the LEHLE P-SPLIT III.
!

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LEHLE GmbH · Germany · www.lehle.com · [e-mail]
6. EXTERNAL POWER SUPPLY
Connect a power supply with a voltage
of 9 – 15 V.
In order that the LITTLE LEHLE III can
work flawlessly, it needs a current sup-
ply. This should supply a minimum of 9
V and a maximum of 15 V. Polarity is of
no importance. The supply voltage is in-
ternally rectified and stabilized in order to
guarantee trouble-free operation. In or-
der to avoid noise it‘s recommendable to
use a single power supply or an output of
a multi power supply oering galvanically
isolated outputs for the LITTLE LEHLE III.
7. LED FOR SWITCHING STATUS
If the LED shows white, the input (1) is di-
rectly connected to the output (5).
The high-intensity LED clearly indicates
the current switching status - even under
bright spotlights.
When you use the LITTLE LEHLE III as an
eects loop switcher and the LED shows
white, the eects are in Bypass, when
blue they are in the signal path.
If you use it as A/B switch between two
amplifiers it means the LED is white for
the amplifier at the output (5) and blue for
the amplifier at the send (3).
Same applies for switching between two
instruments: LED white means that the in-
strument at the input (1) is active, blue ap-
plies for the instrument at the return (4).
8. BASE AND FIXING
If required, mount the LITTLE LEHLE III to
a pedalboard using the mounting kit.
The LITTLE LEHLE III can be mounted to a
plate such as a pedalboard using the two
holes in the bottom of the pedal.
You can find the optional LEHLE Mount-
ing Kit V3 (order number 100981) online
at www.lehle-components.com.
To mount, undo the four housing screws
by using a 2.5 mm Allen Key and detach
the cover.
Then fix the device base to a base plate
using the two screws, the washers and the
spacers of the Mounting Kit.
Attach the cover and tighten the four
housing screws - done!
For flexible solutions we recommend us-
ing 3M Dual Lock™ instead of Velcro for
stability, which you can also find in handy
sizes at www.lehle-components.com
!
Tip: if you are using the Velcro / Dual
Lock™ method, please make a note of
the serial number on the bottom of the
pedal before you cover it, in case you
have a support question for us later and
don‘t fancy dismantling your board!

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LEHLE GmbH · Germany · www.lehle.com · [e-mail]
9. TRUE-BYPASS SWITCH
Here you can switch.
The LITTLE LEHLE III switches all audio
signals controlled by a microcontroller
and an intelligent True-Bypass-Relay-
Circuit with an active pop suppression
function.
Triggered by the easy-action mushroom-
shaped button characteristic of LEHLE
products mounted in the cover so that
your foot pressure is transmitted indirectly
via a spring. Thus the circuit board is not
exposed to mechanical loads, making the
LITTLE LEHLE III virtually indestructible
and guaranteeing years of trouble-free
switching.
According to the foot switch mode follow-
ing configurations are given:
- Latching Mode:
the LEHLE foot switch “latches“ by a press
and release.
- Momentary Mode:
the LEHLE foot switch triggers a contact
and disconnects once released.
- Mixed Mode:
a mix between latching and momentary.
A short press lets the foot switch act as
latching, a longer press is momentary
These three modes can be operated with
or without the pop suppression circuit.
You will find out how to change the oper-
ating mode and the behaviour in chapter
“Selecting the foot switch mode” on page
11.

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LEHLE GmbH · Germany · www.lehle.com · [e-mail]
SELECTING THE FOOT SWITCH MODE AND OPERATING MODE
You can change the behaviour of the foot
switch, so it works latching, momentary or
in a mixed mode.
According to the foot switch mode follow-
ing configurations are given:
• Latching Mode:
The LEHLE foot switch “latches“ by a
press and release.
•• Momentary Mode:
The LEHLE foot switch triggers a contact
and disconnects once released.
••• Mixed M ode:
A mix between latching and momentary.
A short press lets the foot switch act as
latching, a longer press is momentary.
Additionally the three modes can be op-
erated with or without pop suppression. If
the LED flashes white while programming,
the footswitch modes are selected in the
Standard Operating Mode (with pop sup-
pression).
If the LED flashes blue, the footswitch
modes are selected in the Pure Operat-
ing Mode (without pop suppression).
To change the mode please proceed as
follows:
1. Disconnect the power supply.
2. Press and hold the foot switch.
3. Reconnect the power.
4. The white LED starts flashing in follow-
ing order:
• for Latching Mode with pop suppres-
sion circuit
•• for Momentary Mode with pop sup-
pression circuit
••• for Mixed Mode with pop suppres-
sion circuit
5. The blue LED starts flashing in follow-
ing order:
• for Latching Mode without pop sup-
pression circuit
•• for Momentary Mode without pop
suppression circuit
••• for Mixed Mode without pop sup-
pression circuit
6. If you release the foot switch after the
first flash, the Latching Mode is selected.
After 2x flashes you‘re in the Momentary
Mode and after 3x it‘s the Mixed Mode.
After that the blue LED flashes and oers
the same footswitch modes, but without
the pop suppression circuit.
7. The LITTLE LEHLE III turns o and re-
boots.

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LEHLE GmbH · Germany · www.lehle.com · [e-mail]
TYPICAL USES
LITTLE LEHLE III AS AN EFFECTS LOOP SWITCHER
You can use the LITTLE LEHLE III as an
eects loop switcher for individual ef-
fects units, and also for complete pedal
boards.
Not all eects pedals feature True-By-
pass, and those that don’t can cause sig-
nal losses when deactivated.
The LITTLE LEHLE III makes it possible to
eliminate them from the signal path com-
pletely in just one step.
HOW TO DO THIS
1. Connect your instrument to the Input
socket (1) of the LITTLE LEHLE III.
2. Connect the Send (3) of the LITTLE
LEHLE III to the input of the eects unit.
3. Connect the output socket of the ef-
fects unit with the Return socket (4) of the
LITTLE LEHLE III.
4. Connect the Output socket (5) to the
input of your amplifier.
5. There you go!
DEVICE CONNECTION
This works equally well with both mono
and stereo eects. If you are using ste-
reo eects with a mono input, make sure
that the input (1) and send (3) are mono
jacks (TS) and the return (4) and output
(5) are stereo jacks (TRS). Please press
the mono-to-stereo switch (2) too, in or-
der to ensure the mono signal is internally
distributed to stereo correctly.
S
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LITTLE LEHLE
MADE IN GERMANY
Input
Send
Instrument
Input eect(s)
Output Amplifier
Return Output eect(s)
S
R

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LEHLE GmbH · Germany · www.lehle.com · [e-mail]
LITTLE LEHLE III AS AN EFFECTS LOOP SWITCHER FOR INSERTS
BETWEEN SEND AND RETURN OF AN AMPLIFIER
The LITTLE LEHLE III can also be excel-
lently used in FX loops of amplifiers to
loop in pedals or even 19”-eects.
This way a non-switchable amplifier FX
loop can be converted to be switchable
and remote-controlled.
Low-impedance signals with high level
the LITTLE LEHLE III easily switches with-
out loss of signal.
HOW TO DO THIS
1. Connect the send of your amplifier to
the input socket (1) of the LITTLE LEHLE
III.
2. Connect the Send (3) of the LITTLE
LEHLE III to the input of the eects unit.
3. Connect the output socket of the ef-
fects unit with the Return socket (4) of the
LITTLE LEHLE III.
4. Connect the Output socket (5) to the
return of your amplifier.
5. There you go!
DEVICE CONNECTION
S
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LITTLE LEHLE
MADE IN GERMANY
Send
Return Input
Send
Amplifier send
Input eect(s)
Output Amplifier return
Return Output eect(s)
S
R

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LEHLE GmbH · Germany · www.lehle.com · [e-mail]
LITTLE LEHLE III AS AN A/B SWITCHER BETWEEN TWO AMPLIFIERS
The LITTLE LEHLE III 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 compare A and B, when you are in
the studio or the rehearsal room.
HOW TO DO THIS
1. Connect your instrument to the input
socket (1) of the LITTLE LEHLE III.
2. Connect the Send (3) of the LITTLE
LEHLE III to the input of the amplifier 1.
3. Do not use the return socket (4).
4. Connect the Output socket (5) to the
input of your amplifier 2.
5. There you go!
DEVICE CONNECTION
S
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LITTLE LEHLE
MADE IN GERMANY
Input
Send
Instrument
Amplifier 1
Output Amplifier 2
S
Most amplifiers are connected to a pow-
er supply using a three-core cable: two
cores supply the power, while the third
core is the equipment grounding conduc-
tor which grounds the amplifier.
If this ground core is installed, it must, for
safety reasons, never be removed, taped
o or disconnected!
Because of the grounding and the signal
ground of the guitar, two amplifiers con-
nected to one guitar can generate back-
ground noise.
This background noise is called “ground
loop”. You are guaranteed not to have
ground loops when you use the LITTLE
LEHLE III, because it not only switches the
signal back and forth between the ampli-
fiers, but also, simultaneously, the signal
ground.

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LEHLE GmbH · Germany · www.lehle.com · [e-mail]
LITTLE LEHLE III AS AN A/B SWITCHER BETWEEN TWO INSTRUMENTS
In order to swap between two instruments
quickly and easily, you can install the LIT-
TLE LEHLE III between the instruments
and the rest of your setup. If you are play-
ing live with a wireless system, the LITTLE
LEHLE III can easily select between the
receivers too.
It is not always possible to mute your am-
plifier or PA channel, and just pulling out
the plug can cause nasty popping from
the speakers.
HOW TO DO THIS
1. Connect your first instrument to the in-
put socket (1) of the LITTLE LEHLE III.
2. Do not use the send socket (3).
3. Connect your second instrument to the
return socket (4) of the LITTLE LEHLE III.
4. Connect the Output socket (5) to the
input of your amplifier or pedalboard.
5. There you go!
DEVICE CONNECTION
S
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LITTLE LEHLE
MADE IN GERMANY
Input
Return
Instrument 1
Instrument 2
Output Amplifier
R

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LEHLE GmbH · Germany · www.lehle.com · [e-mail]
LITTLE LEHLE III AS A TUNER-MUTE SWITCHER
Even in smaller setups with only one gui-
tar and one amplifier, the LITTLE LEHLE III
can help by muting the signal while you
are tuning, so that your audience and
your bandmates do not hear you.
HOW TO DO THIS
1. Connect your instrument to the input
socket (1) of the LITTLE LEHLE III.
2. Connect your tuner to the send socket
(3).
3. Do not use the return socket (4).
4. Connect the Output socket (5) to the
input of your amplifier or pedalboard.
5. There you go!
DEVICE CONNECTION
S
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LITTLE LEHLE
MADE IN GERMANY
Input
Send
Instrument
Tuner
Output Amplifier
S

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LEHLE GmbH · Germany · www.lehle.com · [e-mail]
LITTLE LEHLE III AS AN EFFECTS LOOP SWITCHER FOR
MICROPHONES
The usage of eects to manipulate the
sound of your voice is already common-
place.
The LITTLE LEHLE III 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 III also switches
other balanced signal sources.
HOW TO DO THIS
1. Connect your microphone to the input
socket (1) of the LITTLE LEHLE III.
2. Connect the send socket (3) to the in-
put of your eects unit.
3. Connect the output to the return socket
(4) of the LITTLE LEHLE III.
4. Connect the output socket (5) to the
input of a mixer.
5. There you go!
DEVICE CONNECTION
S
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LITTLE LEHLE
MADE IN GERMANY
Input
Send
Microphone
Input eect(s)
Output Mixer
Return Output eect(s)
S
R
Signals from microphones that require
phantom power cannot be switched this
way, since this would mean that the phan-
tom power would be switched o and on.
Switching phantom power o and on
generally causes a loud noise.
!

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LEHLE GmbH · Germany · www.lehle.com · [e-mail]
Balanced signal lines are fitted with XLR
connectors or TRS (Tip Ring Sleeve) jack
plugs. In a balanced signal line, the sig-
nal is present in phase at the tip, as in
the case of an unbalanced signal line
(XLR Pin 2). The second signal conduc-
tor carries the same signal, but with the
opposite polarity or mirror-image phase
(Ring, XLR Pin 3). The third conductor is
the screening, and again constitutes the
signal ground (Sleeve, XLR Pin 1).
JACK XLR
CABLE
Sleeve Pin 1
Ground
Ring Pin 3
Signal in mirrored phase
Tip Pin 2
Signal in phase

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LEHLE GmbH · Germany · www.lehle.com · [e-mail]
LITTLE LEHLE III
SIGNAL FLOW DIAGRAM
INPUT (1)
SEND (3)
OUTPUT (5)
RETURN (4)
MO ST (2)
TRUE-BYPASS SWITCH (9)

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LEHLE GmbH · Germany · www.lehle.com · [e-mail]
LEHLE GmbH · Grenzstrasse 153 · 46562 Voerde · Germany
www.lehle.com · [e-mail]
LITTLE LEHLE III OPERATING INSTRUCTIONS V1.1 · 2020-09-01
Copyright 2020 by LEHLE