FM4

The Line 6 FM4 Filter Modeler is a versatile stompbox pedal designed to provide a wide range of filter modeling effects for guitarists. The pedal features digital modeling of 16 classic and collectible filters and synths, offering a diverse selection of iconic and experimental modes, including classic synth and auto-wah emulations. The FM4 boasts 24-bit processing and true bypass functionality, ensuring high-quality sound and signal integrity.

Key features and controls of the Line 6 FM4 Filter Modeler include:
- Model Selector: Allows users to choose from the 16 available filter and synth models.
- FREQ: Typically sets the frequency of the selected filter or synth model.
- Q: Typically sets the width of the filter.
- SPEED: Controls the speed of the filter effect, with specific functions depending on the selected model.
- MODE: Selects the type of filter effect or specific parameters for the chosen model.
- MIX: Adjusts the mix between the dry/direct/unprocessed signal and the processed signal.
- Stomp Switches: Four programmable presets are available at the tap of a toe, eliminating the need for multiple pedals for different effects.

Additionally, the FM4 Filter Modeler supports expression pedal control, allowing users to manipulate one or more parameters of the effect while playing. The pedal can be powered using an optional Line 6 AC power supply or 4 C size batteries for portability.

The FM4 Filter Modeler also features true bypass switching, ensuring that the signal is routed directly from the input jack to the output jack when bypassed, with no processing or analog-to-digital conversion. An alternate bypass mode is available for engaging the DSP while bypassed, suitable for long cable runs.

The pedal includes a comprehensive set of filter models, each with specific controls and characteristics, such as the Voice Box, Obi-Wah, Seeker, Tron Up/Tron Down, Comet Trails, Spin Cycle, Throbber, V-Tron, +Attack Synth, Synth-O-Matic, Octisynth, Slow Filter, Q Filter, Growler, Synth String, and more.