Order code: 1031
Gold-plated Relays & Switches
The signal from the pickups of an electric guitar or bass is so weak that poor-quality cables, cold joints and cheap contact materials ruin your sound. Switch contacts need to be made of special materials to permit loss-free switching of these low-level signals. All Lehle switchers feature special relays and slide switches with gold-plated contacts for totally reliable, absolutely zero-loss switching.
Switching precise, swift and quiet
Swift and precise switching as between different instruments, effects loops or amps is essential in many live setups. To ensure this almost silently and wear-free, we have designed a finely tuned control system with a self developed spring located between the foot switch, our famous mushroom head, and the actual sensing device on the circuit board. A processor based on the ARM Cortex-M technology controls the switching operation very fast and precisely. While a conventional switch can handle a maximum of 20,000 switching operations, the interplay of the components used here enables a service life of 2 million switching operations. A hundred times more!
LEHLE Footswitch
The easy-action mushroom-shaped buttons characteristic of LEHLE products are mounted in the cover, so that your foot pressure is transmitted indirectly only, via a spring. Thus the electronics board is not exposed to mechanical loads, making your LEHLE virtually indestructible and guaranteeing years of trouble-free switching.
Voltage Internally Boosted to 30V
To exploit the dynamics of tube amplifiers to the full, the input voltage of Lehle products bearing this symbol is rectified from the power supply socket, then filtered, stabilized and boosted to 30V.
Adjustable Gain
Adjustment of volume or distortion using a gain controller is a vital feature in many situations. The gain controllers on the corresponding Lehle products feature black anodized aluminium knobs set back into the housing so that they can be easily fingertip rotated but keep their settings during performances and transportation.
  • High-end preamp, buffer and booster
  • Discrete Class A input stage
  • 130 dB dynamic range thanks to 30 V technology
  • Choose between two sound modes
  • Neutral, studio quality sound
  • Switchable boost up to +18 dB
  • Choose between Buffer and True-Bypass operation
  • Balanced output can be used as a DI box

The LEHLE SUNDAY DRIVER SW II is a compact high-end preamp for all types of electric and acoustic instruments - a preamp for electric and acoustic guitars and basses, not to mention other stringed instruments (such as violins, cellos and double basses) to realize their full musical potential. The switchable version expands on the classic LEHLE SUNDAY DRIVER SW II with a soft-touch foot switch, to activate and deactivate the pedal.
The LEHLE-Switch works with a microcontroller and an intelligent True-Bypass-Relay-Circuit with active pop suppression circuit, thereby allowing the LEHLE SUNDAY DRIVER SW II to switch even faster than mechanical switches, noise-free and without wear.
The easy-action mushroom-shaped button characteristic of LEHLE products is mounted in the cover, so that your foot pressure is transmitted indirectly, via a spring. Thus the electronics board is not exposed to mechanical loads, making the LEHLE SUNDAY DRIVER SW II virtually indestructible and guaranteeing years of trouble-free switching.
When ON, its circuit is based on a discrete Class A circuit with JFET technology and provides two modes of operation, selected by a mode selector switch with gold-plated contacts: "D" stands for Driver: in this mode, your guitar signal is amplified, with absolutely no modification, at the input impedance of a guitar amp, efficiently eliminating losses on the route through leads and effects; the signal remains strong and clear, retaining its full dynamics. The second setting "S" - as in Sunday - multiplies the input impedance by five, bringing out previously inaudible details and, as gain increases, giving your guitar a characteristic and unmistakable warmth that has given this preamp its name - the result is a sound as mellow as a sunny Sunday afternoon.
Even at the maximum +18 dB gain setting, the LEHLE SUNDAY DRIVER SW II always stays clean and absolutely free of background noise, thanks to its studio-standard overall dynamic range of 130 dB. To exploit the dynamics of tube amplifiers to the full, the input voltage is also rectified from the power supply socket, then filtered, stabilized and transformed to 30 V.
When OFF, the LEHLE SUNDAY DRIVER SW II provides two different modes of operation: in TB (= True Bypass) mode, the input and output are linked via relay, with zero tonal loss. True-Bypass mode is the best option if you have a small setup with short cable routings and for when a treble booster or old-school fuzz pedal is placed after the LEHLE SUNDAY DRIVER SW II.
If you have long cables or a complex effects board configuration, switch to TS (= True Sound) mode, and the LEHLE SUNDAY DRIVER SW II is active as a buffer, without amplifying the signal in any way.
In this mode, the LEHLE SUNDAY DRIVER SW II operates as a neutral line driver and works with 5 MOhm or 1 MOhm input impedance – depending on the selected S or D mode.
The Bypass mode option enables you to effortlessly and tonefully integrate the LEHLE SUNDAY DRIVER SW II into any setup, no matter how complex.
And not just on Sundays!
We take care of your signal so that you can take care of the music.

Q: What is the effect of an impedance converter?
A: The sound will be freshened up and signal loss through long cable runs will be compensated.
Q: What is the benefit of a buffer/impedance converter before my effects chain? I heard about the SUNDAY DRIVER, but I am uncertain how this works and whether I need this for my pedal board.
A: A high impedance / HiZ signal can be weakened by an increasing number of FX pedals, even true bypass effects. The difference can be felt by connecting your instrument with a short cable directly to your amplifier and focus on the details in sound and dynamics.
Q: How can I compensate the signal loss on my effects board?
A: By using an impedance converter, which provides a high impedance input socket for the instrument signal and a low impedance output signal that is more resistent against loss.
Q: My doublebass pickup delivers a weak signal, can I increase the level without any coloration or distortion?
A: The SUNDAY DRIVER II can increase the signal gain up to 18dB without any loss or alteration of your original signal.
Q: What is the difference between the LEHLE JULIAN and the LEHLE SUNDAY DRIVER?
A: The EQ section makes the difference! The LEHLE JULIAN offers additional controls like the parametric mids and treble which allow individual sound shaping.
The S-Mode: The LEHLE JULIAN does not have an S (= Sunday) Mode whith a higher input impedance.
SW as in Switcher: The LEHLE JULIAN has an On /Off footswitch included as a standard, which comes along with the big LED showing its status. Besides the classical LEHLE SUNDAY DRIVER without switch there is a switchable version, the LEHLE SUNDAY DRIVER SW.
Weight 350 g
Length 90 mm / 3.5"
Width 96 mm / 2.7"
Overall height 47 mm / 1.9"
Supply voltage 9 - 15 V DC
Current consumption 64 - 165 mA
Frequency range 20 Hz - 100 kHz (+/- 0.2 dB)
Total harmonic distortion 0.008 % (0 dBu, 1 kHz)
Impedance input 2 MΩ
Input impedance D-mode 1 MΩ
Input impedance S-mode 5 MΩ
Impedance output 220 Ω
Max input level 7.7 V RMS / 20 dBu
Max output level 9.8 V RMS / 22 dBu
Max. gain 18 dB
Level noise floor -110 dBu (20 Hz - 20 kHz)
Gitarre & Bass 2020.02
Dirk Groll
This is really high end!
In the listening test, both devices fully deliver on all promises, scoring with the highest quality technology, practical features and the extremely clean sound transmission. This is really high end!

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I have the following questions on the product LEHLE SUNDAY DRIVER SW II (Order code: 1031)
Joachim Joki Schaller
Tel +49 2855 850070