
OPERATING INSTRUCTIONS
LEHLE MONO VOLUME S
LEHLE MONO VOLUME S#
Dear Musician!
Thank you for purchasing your LEHLE MONO VOLUME S!
I have been building units that switch, split and route signals with no technical compromises and with maximum musical fidelity since 1999. Your new LEHLE MONO VOLUME S comprises only the very best components. Every assembly of your LEHLE MONO VOLUME S has been made and tested in Germany.
Your LEHLE MONO VOLUME S 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 LEHLE MONO VOLUME S!

General Description#
1. USB-C-SOCKET
By means of this socket you can use the LEHLE MONO VOLUME S as a MIDI-USB expression pedal, supply it with power and update the firmware.
2. INPUT SOCKET
Connect your instrument here.
The input of the LEHLE MONO VOLUME S processes signals of electric and acoustic stringed instruments, as guitars and basses, steel string and nylon string acoustics and acoustic string instruments of all kinds (such as violins with pickup systems). The input impedance of the LEHLE MONO VOLUME S is approx. 2 MOhm. It doesn’t matter if the connected signal has high or low impedance, or if it comes from a passive or an active pickup system. This means you can connect even synthesizers, keyboards or the send of your amp’s effects loop.
3. DIR-SOCKET
Connect a tuner or a second amp here.
The input signal is mirrored to this output with exactly the same level (unity gain). The DIR Out is buffered, which means you can connect both high and low impedance inputs to the DIR Out without influencing the sound of the input signal. If you are using a tuner, you can mute the VOL out (4) if the rocker is in heel position, so the DIR Out will provide a signal only.
4. VOL-SOCKET
Connect your target device here.
For instance, this would be an amplifier, an effects pedal, a mixing desk, a stage box or an audio interface. This output, like the DIR output (3), is low impedance too, and does not change its impedance when the volume is altered via the volume pedal. Thus the sound stays always the same – independent of the volume.
5. EXTERNAL POWER SUPPLY
Connect a power supply with a voltage of 9 – 15 V.
In order that the LEHLE MONO VOLUME S can work flawlessly, it needs a current supply. This should supply a minimum of 9 V and a maximum of 15 V. Polarity is of no importance. To guarantee trouble free operation the supplied voltage is internally rectified, filtered, stabilized and then transformed to 30 V headroom. In order to avoid noise it’s recommendable to use a single power supply or an output of a multi power supply offering galvanically isolated outputs for the LEHLE MONO VOLUME S. If the LEHLE MONO VOLUME S is connected 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, 3 and 4) it’s better to use its own power supply.
6. LED OF THE POWER SOCKET
This LED shows that your pedal is active.
Congratulations: The white LED shows you that the LEHLE MONO VOLUME S has started correctly and is active. If you move the rocker of the pedal, a blue LED instead of the white LED indicates that you are changing the volume at the socket VOL (4), resp. that you are sending MIDI data if it’s used as an expression pedal with your computer.
7. FUNCTION BUTTON
Button with multiple functions
First of all the FUNCTION BUTTON acts to recall the presets of the pedal. By means of pushing the button several times, you are toggling between them, shown by the FUNCTION LEDs (8). You can expect different boost stages as well as an individual preset. What exactly (you can expect) can be looked up in the chapter „DESCRIPTION OF THE PRESETS“. The FUNCTION BUTTON is also used to calibrate the pedal. You can read how this is done in the chapter „CALIBRATION OF THE PEDAL RANGE“.
8. FUNCTION LEDs
The bright FUNCTION LEDs are indicating which preset you are in. If the P4 LED flashes, you are in P4.1. Please read the chapter „DESCRIPTION OF THE PRESETS“.
9. 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 MONO VOLUME S will be heavier. Turning the screw counterclockwise diminishes the resistance when pressing and gives the rocker a lighter feel.
10. BASE AND FIXING
If needed, you can mount the LEHLE MONO VOLUME S to a plate such as a pedalboard.
The LEHLE MONO VOLUME S can easily be mounted to a plate using the prepared fixing system of the pedal. You need 4 screws (4.2×13) 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 onto the base plate. Now drill at the site of the later screw holes a hole with a diameter of approximately 2.5 mm (1/10 inch). Then turn in two of the four screws together with the washers just halfway.
Slowly slide the LEHLE MONO VOLUME S 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 MONO VOLUME S 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 stable and can also be easily removed.
For flexible solutions we recommend using 3M Dual Lock™ instead of velcro for stability.
You can find replacement feet, Screw- and 3M Dual Lock™ sets at www.lehle-components.com
If you are using the velcro / Dual Lock™ method, please make a note of the serial number from 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!
Description of the Presets#
By using the FUNCTION BUTTON (7) you can recall the presets.
If you are in heel position, the pedal is at -95 dB, so virtually muted. This applies for every preset.

However in heel position you can expect this:
0 dB: If the rocker is in toe position, your input signal is at the VOL output (4) unaltered with unity gain.
5 dB: If the rocker is in toe position, your input signal is at the VOL output (4) with a boost of + 5 dB.
10 dB: If the rocker is in toe position, your input signal is at the VOL output (4) with a boost of + 10 dB.
P4: This is the preset 4. It’s the chef’s speciality and remains an audiophile surprise.
P4.1: This preset can be reached if you press the FUNCTION BUTTON (7) once again. The corresponding LED starts flashing.
If it flashes slowly, your input signal is at the VOL output (4) unaltered with unity gain.
If you give the rocker in toe position a little extra kick, like you would hit a foot switch, the LED starts flashing fast and the boost with +12 dB is activated. Give the rocker a little kick again, you deactivate the boost and the LED flashes slowly again.
Depending on how clean, crunchy or distorted your following effects and amps are adjusted, the curve and boost of the presets might have different impact on them.
Calibration of the Pedal Range#
In factory setting the pedal range of the LEHLE MONO VOLUME S is perfectly calibrated.
Normally it doesn’t need a calibration again and is only necessary, if a mechanical component has been replaced.
The calibration does not change the minimum or maximum volume, too.

- Press the FUNCTION BUTTON (7) for 5 seconds.
- The FUNCTION LEDs (8) start flashing.
- 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 FUNCTION LEDs stops flashing, go off and the calibration process is finished. The LEHLE MONO VOLUME S reboots again.
If the LEDs flash in a row after the calibration, the process has been interrupted. The pedal will load the previous configuration at the next start.
Please start the calibration process again.