The Lehle Module SW-OFL is a compact true bypass switching unit: a small relay-based module that opens and closes a signal path without putting any circuitry in the way of your guitar's signal. Lehle describes it as a true bypass switching unit with a relay and an active pop suppression function controlled by an intelligent microcontroller circuit, so the switch transition is handled electronically rather than left to click and pop1.
Unlike a boxed switching pedal, the SW-OFL is an open frame version with leads. It is meant to be wired into a larger build, a custom board or another enclosure rather than stomped on its own. Lehle also makes the Module SW family in other form factors, including the Module SW-L and the Module SW-OF1.
Switching design and operating modes
The switching element is a gold-plated contact relay, which Lehle says gives lossless signal routing. Because the audio passes through relay contacts rather than an electronic switch stage, the module stays true bypass: when the path is closed, your signal meets only the relay contacts1.
The module offers three operating modes, set to suit how the module is triggered in your build1:
| Mode | Behavior |
|---|---|
| Latching | Holds its state until switched again |
| Momentary | Switches only while triggered |
| Mixed Mode | Combines latching and momentary behavior |
The pop suppression works alongside the relay. Lehle states that the Module SW has an active pop suppression function controlled by an intelligent microcontroller circuit, aimed at removing the clicks and pops that mechanical switching can introduce when a signal path is opened or closed1.
Lehle lists the SW-OFL module at €29.90* EUR1, and at 8 g [0.3 oz] it is the lightest of the module's listed weights2. Plan your supply and mounting accordingly.
Power and signal level
The module runs on a 9V supply and draws 7 mA with current consumption off, according to Lehle's datasheet. Its maximum signal level is 12 dBu, which covers typical instrument and line-level signals passing through the relay2.
| Specification | Value |
|---|---|
| Supply voltage | 9V2 |
| Current consumption OFF | 7 mA2 |
| Maximum signal level | 12 dBu2 |
| Weight | 8 g [0.3 oz]2 |
| Lead length | 100 mm [3.94"]2 |
Size, form and where it is made
The module is smaller than a 9-volt battery and weighs 8 g [0.3 oz], so it fits where a full pedal cannot. As the open frame version, it comes with leads of 100 mm [3.94"] for wiring it in12. Lehle lists it as made in Germany and currently in production1.
What the open frame form means in practice:
- No enclosure or footswitch of its own: the module is wired in via its leads1
- Small enough to sit inside another build, at less than the size of a 9-volt battery and 8 g1
- Same switching design as the rest of the Module SW family, including the relay, pop suppression and the three modes1
Videos
Raul Neves
Questions
Is the Lehle Module SW-OFL true bypass?
Yes. Lehle describes the Module SW-OFL as a compact true bypass switching unit built around a relay. The switching is done by a gold-plated contact relay, which Lehle says gives lossless signal routing, and an active pop suppression function controlled by an intelligent microcontroller circuit quiets the switch transition.
What is the difference between the Lehle Module SW-OFL and the SW-OF?
The SW-OFL is the open frame version of the module: it comes with leads rather than being housed for pedalboard mounting, and its leads are 100 mm long. Both share the same switching design, including the relay, the pop suppression circuit and the three operating modes. Lehle also lists a Module SW-L variant with a different form factor.
Does the Lehle Module SW-OFL have a pop suppression circuit?
Yes. Lehle states that the Module SW has an active pop suppression function controlled by an intelligent microcontroller circuit, working alongside the true bypass relay. That is aimed at removing the clicks and pops that mechanical switching can introduce when a signal path is opened or closed.
Where is the Lehle Module SW-OFL made?
Lehle lists the Module SW-OFL as made in Germany. The company is based in Voerde, Germany, and the module is currently in production according to Lehle's product page.
How long are the leads on the Lehle Module SW-OFL?
The leads on the open frame version are 100 mm, which is about 3.94 inches, according to Lehle's datasheet. The module itself is smaller than a 9-volt battery and weighs 8 g, so the leads are what connect it into a signal path.
Sources (2)
- LEHLE MODULE SW-OFL, Lehle GmbH
- LEHLE MODULE SW Datasheet V1.0.cdr, Lehle GmbH, 2019-09-17
