Lehle DUAL EXPRESSION User manual

OPERATING INSTRUCTIONS
LEHLE DUAL EXPRESSION

LEHLE GmbH · Germany · www.lehle.com · [e-mail]
Dear Musician!
Thank you for purchasing your
LEHLE DUAL EXPRESSION!
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 LEHLE
DUAL EXPRESSION comprises only the
very best components.
Every assembly of your LEHLE DUAL
EXPRESSION has been made and tested
in Germany.
Your LEHLE DUAL EXPRESSION is of
extremely robust design and construc-
tion, 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 LEHLE DUAL
EXPRESSION!

LEHLE GmbH · Germany · www.lehle.com · [e-mail]
CONTENT
Introduction
Technical data
How does an expression pedal work?
General description
Calibration of the pedal range and switch output
Restoring the factory setting
Typical uses of the LEHLE DUAL EXPRESSION
as a classic expression pedal
with a KEMPER™ PROFILER™ Head/ PROFILER™ Stage
with a multi eects pedal
with an eects pedal and an amplifier
with a synthesizer
as an attenuator for control voltage (CV)
as MIDI-USB expression pedal
User Flow Maps
Functional diagram of the LEHLE DUAL EXPRESSION
4
5
6
7
14
16
17
18
19
20
22
23
24
25
27
KEMPER™ and PROFILER™ are registered trademarks of Kemper GmbH

4
LEHLE GmbH · Germany · www.lehle.com · [e-mail]
Express yourself, twice!
The LEHLE DUAL EXPRESSION is an ac-
tive, wear-free expression pedal equipped
with a precise magnetic sensor.
Known from the LEHLE VOLUME pedals,
this sensor uses the Hall eect, named af-
ter Edwin Hall, to measure the strength of
magnetic fields.
In the LEHLE DUAL EXPRESSION the
Hall sensor is accurately calibrated to the
built-in magnet and the control range of
the pedal – where the pedal moves only
the magnet, whose distance is measured
by the Hall sensor.
Two digital potentiometers, working with
analogue voltages, are used for the pre-
cise and reliable generation of the ex-
pression data.
This technology allows distinctly more
accurate operation than is oered by
conventional expression pedals with
mechanical potentiometers. There is no
mechanical wear, avoiding the need
for maintenance or complicated adjust-
ments.
Both outputs can control nearly all com-
mon devices with expression inputs from
5kΩ to 100kΩ, regardless if TS, TRS or
RTS – the polarity can be switched and
stored using the soft-push buttons.
Alternatively, the 10K output can be set to
work as a latching or momentary switch,
if the pedal is pushed in fully toe position.
Then, e.g. the channel of an amp can be
changed or, connected to a switch-input
of a digital device, any desired function
can be controlled.
In use, the LEHLE DUAL EXPRESSION is
extremely smooth and steady under foot,
as it is equipped with low-friction bear-
ings of a high-performance polymer. By
means of an adjusting screw the mobility
of the pedal can be modified with great
precision.
Compared to the LEHLE MONO
VOLUME we were able to reduce the
weight by 50% and the size by 35% – with
the same rugged stability. It’s even 2 cm
flatter, however the pedal range stays the
same - just as comfortable and respon-
sive as the larger models.
Light, small, and twice the precise
expression:
LEHLE DUAL EXPRESSION.
INTRODUCTION

5
LEHLE GmbH · Germany · www.lehle.com · [e-mail]
TECHNICAL DATA
766 g
200 mm
90 mm
47 mm
9-15 V DC
max. 100 mA
10 V
Weight
Length
Width
Overall height
Supply voltage
Current consumption
Max Level

6
LEHLE GmbH · Germany · www.lehle.com · [e-mail]
HOW DOES AN EXPRESSION PEDAL WORK?
An expression pedal usually controls a
specific value of an eects device.
For example you want to use your foot
to control the mix amount of your delay
pedal.
In most cases your eects pedal oers a
control / potentiometer that cares about
the mix amount of your delay pedal. This
potentiometer will now be replaced by an
external expression pedal, that also usu-
ally works with a potentiometer.
The procedures, how this is being done,
are as complicated as they are varied.
Typically, your eects pedals send a volt-
age of 3.3 V or 5 V to the potentiom-
eter of the expression pedal. The poten-
tiometer as a variable resistor routes a
part of the voltage back. The sent back
voltage – also called control voltage – is
being changed by the position of the po-
tentiometer. The eects pedal measures
the control voltage and thus can modify
a parameter. In the above-mentioned ex-
ample the mix amount would be changed.
The individual cables and polarities in
summary:
RTS: the control voltage is being applied
to the ring of the TRS jack.
TRS: the control voltage is being applied
to the tip of the TRS jack.
TS: here the eects pedal measure the
voltage between sleeve and tip of the TS
jack.
Instead of stereo jacks or mono jacks we
are talking rightly about TRS and TS jacks. !

7
LEHLE GmbH · Germany · www.lehle.com · [e-mail]
GENERAL DESCRIPTION
1. USB SOCKET
By means of this socket you can update
the firmware and use the LEHLE DUAL
EXPRESSION as a MIDI-USB expression
pedal and supply it with power, too.
In order to update your LEHLE DUAL
EXPRESSION, you need to connect it with
a USB cable to your PC or Mac.
You will find a step-by-step instruction in
the separate manual “UPDATE OF THE
PEDAL” on our website www.lehle.com.
If you want to use your LEHLE DUAL
EXPRESSION as MIDI-USB pedal, e.g.
to send MIDI parameters to your DAW,
your amp simulation software or software
synthesizer, please follow the instructions
in chapter “LEHLE DUAL EXPRESSION AS
MIDI-USB EXPRESSION PEDAL” on page
24.
2
34
5
6
7
1

8
LEHLE GmbH · Germany · www.lehle.com · [e-mail]
2. 50K SOCKET
Connect your eects pedal or keyboard
with a jack cable to this socket.
The 50K socket controls your eects ped-
al or keyboard that works with expression
pedals within a range of 25kΩ to 100kΩ.
The 50K socket has 3 dierent socket-
modes:
Polarity Autodetection, TRS and RTS.
By pressing the soft button (7) the socket-
mode will be changed:
- Polarity Autodetection:
Both LEDs are white, as long as no jack
is plugged in.
Once you connect a jack to the socket,
the LEHLE DUAL EXPRESSION measures
the polarity (RTS, TRS or TS) and adapts
to the polarity automatically.
During the measuring process both white
LEDs are flashing alternately.
After the measuring process only one LED
is on, according to the matching polarity.
The pedal stores the selected mode, as
long as a jack is connected to the socket.
2. TRS
Only the TRS LED is on.
The control voltage is tapped at the tip of
the TRS jack.
3. RTS
Only the RTS LED is on.
The control voltage is tapped at the ring
of the TRS jack.
This mode works for TS with a TS jack,
too.
It’s best to try the Polarity Autodetection
first. Ensure that both LEDs of the 50K
socket are on whilst there is no jack con-
nected. Now connect the TRS or RTS/TS
jack to the 50K socket. After the LEDs
stopped flashing and only one is on, your
eects pedal or keyboard can receive ex-
pression data.
Move the rocker of the LEHLE DUAL
EXPRESSION. If your eects pedal
doesn’t react properly, press the 50K but-
ton (7) to switch from Polarity Autodetec-
tion to TRS or RTS/TS. The alteration of
the polarity causes tip (T) and ring (R) to
be swapped. Thus you are flexible to act
best on every eects pedal.
Refer to the manual of your eects pedal
to find out, if you need a TS-TS cable
(coll. monocable) or TRS-TRS cable (coll.
stereo cable) to make a proper connec-
tion.
50K
Attention: The LEHLE DUAL EXPRESSION
can work with voltages up to 10V.
Higher voltages will be blocked by diodes
to protect the electronics of the pedal.
Please refer to the manual of your eects
pedal to find out how much voltage your
pedal provides.
!

9
LEHLE GmbH · Germany · www.lehle.com · [e-mail]
3. 10K SOCKET
Connect your eects pedal or keyboard
with a jack cable to this socket.
The 10K socket controls your eects ped-
al or keyboard that works with expression
pedals within a range of 5kΩ to 20kΩ.
This socket can also be set to a latching
or momentary switch and, e.g. switch the
channel of your amplifier.
The 10K socket has 5 dierent socket-
modes:
Polarity Autodetection, TRS, RTS,
momentary switch and latching switch.
By pressing the soft button (6) the socket-
mode will be changed:
- Polarity Autodetection:
Both LEDs are white, as long as no
jack is plugged in. Once you connect
a jack to the socket, the LEHLE DUAL
EXPRESSION measures the polarity (RTS,
TRS or TS) and adopts to the polarity au-
tomatically. During the measuring pro-
cess both white LEDs are flashing alter-
nately. After the measuring process only
one LED is on, according to the matching
polarity. The pedal stores the selected
mode, as long as a jack is connected to
the socket.
- TRS
Only the TRS LED is on.
The control voltage is tapped at the tip of
the TRS jack.
- RTS
Only the RTS LED is on.
The control voltage is tapped at the ring
of the TRS jack.
This mode works for TS with a TS jack,
too.
- Momentary switch
The rear LED of the 10K socket flashes
blue. A contact is made between tip and
sleeve, once the rocker reaches a specific
position. If the contact is made, the front
LED is white.
- Latching switch
The rear LED of the 10K socket is con-
sistently blue. A contact is made between
tip and sleeve, once the rocker reaches a
specific position. The contact stays closed
until the rocker reaches the position
again. If the contact is closed, the front
LED is white.
If you use the 10K socket as an expres-
sion controller and not as a switch, it’s
best to try the autodetection first.
Ensure that both LEDs of the 10K socket
are on whilst there is no jack connected.
Now connect the TRS, resp. TS jack to the
10K socket. After the LEDs stop flashing
and only one is on, your eects pedal or
keyboard can receive expression data.
Move the rocker of the LEHLE DUAL
EXPRESSION. If your eects pedal doesn’t
react properly, press the 10K button (6)
to switch from Polarity Autodetection to
10K

10
LEHLE GmbH · Germany · www.lehle.com · [e-mail]
TRS or RTS, resp. TS. The alteration of the
polarity causes tip (T) and ring (R) to be
swapped. Thus you are flexible to act best
on every eects pedal.
Refer to the manual of your eects pedal
to find out, if you need a TS-TS cable
(coll. mono cable) or TRS-TRS cable (coll.
stereo cable) to make a proper connec-
tion.
If you are using the 10K socket as a latch-
ing or momentary switch, you are able to
control a switch input of an eects pedal.
In combination with a complex multi ef-
fects pedal it is possible, e.g. to simulate
a Wah pedal which is being activated
and deactivated when the relay is trig-
gered by you.
Refer to the manual of your eects pedal
to find out, if you need a TS-TS cable
(coll. mono cable) or TRS-TRS cable (coll.
stereo cable) to make a proper connec-
tion.
In factory setting the relay will be trig-
gered in toe position in the last few mil-
limetres.
Nevertheless, you can adjust in which po-
sition of the pedal range the relay shall
be triggered. E.g. it’s possible to set the
trigger point at heel position or some-
where in between the range.
You will find out how to do this in the
chapter “CALIBRATION OF THE PEDAL/
TRAVEL RANGE AND SWITCH OUT-
PUT” on page 14/15.
4. EXTERNAL POWER SUPPLY
Connect a power supply with a voltage
of 9 – 15 V.
In order that the LEHLE DUAL
EXPRESSION can work flawlessly, it
needs a current supply. This should sup-
ply a minimum of 9 V and a maximum of
15 V. Polarity is of no importance. The
supply voltage is internally rectified and
stabilized in order to guarantee trouble-
free operation. In order to avoid noise it’s
recommendable to use a single power
supply or an output of a multi power sup-
ply oering galvanically isolated outputs
for the LEHLE DUAL EXPRESSION.
If the LEHLE DUAL EXPRESSION is con-
nected to a computer via a USB cable to
use it as MIDI-USB expression pedal or
to update the firmware, you don’t need
an external power supply. However, for
the standard operation with connected
sockets (2 and 3) it’s better to use its own
power supply.
Attention: The LEHLE DUAL EXPRESSION
can work with voltages up to 10V.
Higher voltages will be blocked by diodes
to protect the electronics of the pedal.
Please refer to the manual of your eects
pedal to find out how much voltage your
pedal provides.
!

11
LEHLE GmbH · Germany · www.lehle.com · [e-mail]
5. LED OF THE POWER SOCKET
This LED shows that your pedal is active.
Congratulations: The white LED shows
you that the LEHLE DUAL EXPRESSION
has started correctly and is active.
If you move the rocker of the pedal, a
blue LED instead of the white LED indi-
cates that data is being sent via the sock-
ets (2 and 3).
6. BUTTON FOR 10K SOCKET
Here you can change the mode of the
10K socket.
Press this soft touch button to select if the
10K socket (3) should provide expression
data (TRS/RTS/TS) or work as a latching
switch or momentary switch.
In Factory setting the Polarity Autodetec-
tion is selected, to automatically switch
between TRS, RTS or TS.
You will find out how to change the socket
modes and what these are doing at point
“3. 10K SOCKET” on page 9.
7. BUTTON FOR 50K SOCKET
Here you can change the mode of the
50K socket.
Press this soft touch button to select if the
50K socket (2) should provide TRS, RTS
or TS expression data.
In Factory setting the Polarity Autodetec-
tion is selected to automatically switch
between TRS, RTS or TS.
You will find out how to change the socket
modes and what these are doing at point
“2. 50K SOCKET” on page 8.
RTS/TRS
RTS/TRS

12
LEHLE GmbH · Germany · www.lehle.com · [e-mail]
8. PEDAL FEEL
Turn this screw to adjust the feel of the
pedal.
If you turn this screw clockwise, you tighten
the brake. This way the pedal feel of the
LEHLE DUAL EXPRESSION will be heav-
ier. Turning the screw counterclockwise
diminishes the resistance when pressing
and gives the rocker a lighter feel.
9. BASE AND FIXING
If needed, you can mount the LEHLE
DUAL EXPRESSION to a plate such as a
pedalboard.
The LEHLE DUAL EXPRESSION can easily
be mounted to a plate using the prepared
fixing system of the pedal.
You need 4 screws (4.2x13) and 4 M4
washers.
First, we recommend that you pull out the
rubber feet on the bottom.
Place the pedal without the rubber feet
in the position where you want to attach
it to the board. Use a fine-point pen or
a sharp pencil to sketch the subsequent
screw holes through the 4 mounting holes
8
99
You can find replacement feet,
Screw- and 3M Dual Lock™ sets at
www.lehle-components.com

13
LEHLE GmbH · Germany · www.lehle.com · [e-mail]
onto the base plate. Now drill at the site
of the later screw holes a hole with a di-
ameter of approximately 2.5 mm (1/10
inch).
Then turn in two of the four screws to-
gether with the washers just halfway.
Slowly slide the LEHLE DUAL
EXPRESSION with the holes under
the screw heads of the screws already
screwed in. Make sure that the washers
are placed between the bottom plate of
the LEHLE DUAL EXPRESSION and the
screw head to protect the paint.
Now you can turn in the remaining two
screws and spacers through the other two
mounting holes. Tighten those screws only
slightly, then fix the screws you first turned
in. This type of mounting is extremely sta-
ble and can also be easily removed.
For flexible solutions we recommend us-
ing 3M Dual Lock™ instead of velcro for
stability.
!
If you are using the velcro / Dual Lock™
method, please make a note of the serial
number from the bottom of the pedal be-
fore you cover it, in case you have a sup-
port question for us later and don‘t fancy
dismantling your board!

LEHLE GmbH · Germany · www.lehle.com · [e-mail]
14
In factory setting the pedal range of the
LEHLE DUAL EXPRESSION is perfectly
calibrated and the switch output of the
10K socket is being triggered in the last
few millimetres.
Normally, it doesn’t need a calibration
again. Nevertheless, you can adjust the
pedal to your own requirements.
1.) Entering the calibration process menu
To enter the calibration process menu,
first disconnect the power supply connec-
tion.
Press and hold the 10K soft touch button
and reconnect the power supply connec-
tor. You can now release the soft touch
button.
The blue 10K switch LED and the white
50K TRS LED are flashing alternately.
2. Calibrating the pedal range
In order to calibrate the pedal range,
where the minimum (heel) and the maxi-
mum (toe) position of the pedal range
should be reached, in the calibration pro-
cess menu (1.) the 50K soft touch button
needs to be pressed.
The 50K TRS LED flashes.
Move the rocker within 5 seconds (say
“Lehle switcher” five times) to the most
minimal heel position and then into the
maximum toe position.
The pedal learns these two positions
and stores the values inside. After the 5
seconds the 50K TRS LED stops flashing,
goes o and the calibration process is
finished.
The LEHLE DUAL EXPRESSION reboots
again.
How long the pedal range shall be, is
your decision.
This can be all the way to the stop or
shortly before, if you like a decreased
pedal range.
As in the factory setting, we recommend
the use of the whole pedal range, since
minimum and maximum values can often
be set at the eects pedal itself.
CALIBRATION OF THE PEDAL RANGE AND SWITCH OUTPUT
!
On page 25 you will find a user flow
map, where all these procedures are
shown.

15
LEHLE GmbH · Germany · www.lehle.com · [e-mail]
3. Calibration of the relay switch output
The relay of the 10K socket is an elec-
tronic switch, which can perform a mo-
mentary or latching switch signal, e.g. to
switch a channel at an amp or control a
switch-input of a digital device.
You can set the position where the relay
shall be triggered.
In the calibration process menu (1.) the
10K soft touch button needs to pressed.
The blue switch LED starts flashing.
Move the rocker within 3 seconds (say
“Lehle switcher” three times) to the
position you want the relay to be trig-
gered.
The maximum position will be learned
and stored inside.
The calibration process is finished when
the blue switch LED stops flashing and
goes o.
The LEHLE DUAL EXPRESSION reboots
again.
A classic usage would be to move the
rocker to the maximum toe position and
then give it a little push with your toes.
This way you can simulate the behaviour
of a typical Wah pedal switch.
It even works in reverse: Stay within the
3 seconds in the most minimal position.
This way the relay would be triggered if
you are moving into the heel position.
Even in the mid of the pedal range the
relay can be triggered.
!
On page 25 you will find a user flow
map, where all these procedures are
shown.

16
LEHLE GmbH · Germany · www.lehle.com · [e-mail]
RESTORING THE FACTORY SETTING
If you decide to restore all settings back
to the factory setting, please proceed as
follows:
- Disconnect the power supply connec-
tion.
- Press and hold the 10K soft touch but-
ton.
- Reconnect the power supply connec-
tion.
- The LED of the power socket (5) is flash-
ing alternately white and blue.
- After approx. 3 seconds the LEDs go o
and the LEHLE DUAL EXPRESSION re-
boots again.
Every setting and calibration made by
you is reset.
!
On page 26 you will find a user flow
map, where all these procedures are
shown.

17
LEHLE GmbH · Germany · www.lehle.com · [e-mail]
TYPICAL USES
LEHLE DUAL EXPRESSION AS A CLASSIC EXPRESSION PEDAL
Control of a specific parameter of your
eects pedal is probably the most popu-
lar application.
If you are unsure how to set the param-
eter you wish to control, if you need a TRS
or TS cable and if you should use the 10K
or 50K socket, please refer to the manual
of your eects pedal.
How to do this:
1. At the LEHLE DUAL EXPRESSION the
LEDs of RTS and TRS should be both on.
This way the Polarity Autodetection is ac-
tive.
2. Connect the 50K or 10K socket to the
expression input socket of your eects
pedal.
3. After the LEDs of RTS and TRS now
have started and stopped flashing, the
LEHLE DUAL EXPRESSION has selected
the correct polarity automatically.
4. Move the rocker of the LEHLE DUAL
EXPRESSION.
5. There you go!
50K EXP socket eects pedal
EXP socket eects pedal10K
DEVICE CONNECTIONS
If your eects pedal doesn‘t react
properly:
- Try the other output socket (2 or 3) of
the LEHLE DUAL EXPRESSION.
- Depending on which output socket you
are using (2 or 3), toggle the 10K button
(6) or the 50K button (7) to change the
polarity manually.

18
LEHLE GmbH · Germany · www.lehle.com · [e-mail]
LEHLE DUAL EXPRESSION WITH A KEMPER™PROFILER™HEAD / PRO-
FILER™STAGE
By means of the additional 10K socket as
a switching output, it’s very easy and flex-
ible to control the KEMPER™ PROFILER™
devices. This way you can activate and
deactivate, e.g. the Wah pedal or any
other eects in the KEMPER™.
How to do this:
1. At the LEHLE DUAL EXPRESSION the
LEDs of RTS and TRS should be both on.
This way the Polarity Autodetection is ac-
tive.
In order to use the switching function of
the 10K socket, its function must be ac-
tivated. Hit the 10K button (6), until the
LED flashes blue, so the LEHLE DUAL
EXPRESSION provides the momentary
switch function when the rocker is in toe
position.
2. Connect the 50K socket with a TRS ca-
ble to the expression pedal input socket
of your KEMPER™.
3. After the LEDs of RTS and TRS now
have started and stopped flashing, the
LEHLE DUAL EXPRESSION has selected
the correct polarity automatically.
4. Connect the 10K socket with a TRS
cable to the expression pedal 2 / switch
input socket of your KEMPER™.
5. Move the rocker of the LEHLE DUAL
EXPRESSION.
6. In the settings of your KEMPER™ you
can select which parameter should be
controlled.
7. There you go!
DEVICE CONNECTIONS
50K KEMPER™ pedal input
KEMPER™ pedal 2 / switch
input
10K
KEMPER™ and PROFILER™ are registered trademarks of Kemper GmbH

19
LEHLE GmbH · Germany · www.lehle.com · [e-mail]
LEHLE DUAL EXPRESSION WITH A MULTI EFFECTS PEDAL
Some multi eects pedals have multi-
ple control inputs for expression pedals.
With the LEHLE DUAL EXPRESSION you
can use two inputs and by means of the
10K socket trigger the switching function
which can use your multi eects pedal on
the other hand to, e.g. switch a preset,
activating a Wah pedal or whatsoever
your eects pedal makes possible.
How to do this:
1. At the LEHLE DUAL EXPRESSION the
LEDs of RTS and TRS should be both on.
This way the Polarity Autodetection is ac-
tive. In order to use the switching func-
tion of the 10K socket, its function must
be activated. Hit the 10K button (6), until
the LED flashes blue, so the LEHLE DUAL
EXPRESSION provides the momentary
switch function when the rocker is in toe
position.
2. Connect the 50K socket to the expres-
sion pedal input socket of your multi ef-
fects pedal.
3. After the LEDs of RTS and TRS now
have started and stopped flashing, the
LEHLE DUAL EXPRESSION has selected
the correct polarity automatically.
4. Connect the 10K socket to the second
expression pedal input socket of your
multi eects pedal.
5. Move the rocker of the LEHLE DUAL
EXPRESSION.
6. In the settings of your multi eects ped-
al you can select which parameter and
switching function should be controlled.
7. There you go!
DEVICE CONNECTIONS
50K Multi eects pedal input
Multi eects pedal input 2 /
switch input
10K

20
LEHLE GmbH · Germany · www.lehle.com · [e-mail]
LEHLE DUAL EXPRESSION WITH AN EFFECTS PEDAL AND AN
AMPLIFIER
The 10K socket can be used as a mo-
mentary or latching switch. This way you
can control external devices.
Channels of amplifiers are usually
switched by a footswitch. How about
doing this with your LEHLE DUAL
EXPRESSION and simultaneously control-
ling an eects pedal?
How to do this as a momentary switch:
1. At the LEHLE DUAL EXPRESSION the
LEDs of RTS and TRS should be both on.
This way the Polarity Autodetection is
active.
In order to use the switching function
of the 10K socket, its function must be
activated.
Hit the 10K button (6), until the LED flash-
es blue, so the LEHLE DUAL EXPRESSION
provides the momentary switch function
when the rocker is in toe position.
2. Connect the 50K socket to the expres-
sion pedal input socket of your multi ef-
fects pedal.
3. After the LEDs of RTS and TRS now
have started and stopped flashing, the
LEHLE DUAL EXPRESSION has selected
the correct polarity automatically.
4. Connect the 10K socket to the foot-
switch input of your amplifier.
5. Move the rocker of the LEHLE DUAL
EXPRESSION. In the position the LEHLE
DUAL EXPRESSION triggers the relay
(usually in the toe position), the channel
of your amplifier is being switched.
6. There you go!
DEVICE CONNECTIONS
50K EXP socket eects pedal
Amplifier footswitch input10K