# FDS instrument editor The FDS instrument editor contains three tabs: FDS, Wavetable and Macros. ## FDS here you can edit FDS-specific settings. - **Compatibility mode**: DO NOT ENABLE. this exists for DefleMask compatibility. leave it alone. - **Modulation depth**: sets frequency modulation depth. - **Modulation speed**: sets frequency modulation speed. - **Modulation table**: this allows you to define a waveform for frequency modulation. - the range is -4 to 3. - a value of -4 will reset the modulator. ## Wavetable this allows you to enable and configure the Furnace wavetable synthesizer. see [this page](wavesynth.md) for more information. ## Macros - **Volume**: volume sequence. - **Arpeggio**: pitch sequence. - **Waveform**: wavetable sequence. - **Pitch**: fine pitch. - **Mod Depth**: modulation depth. - **Mod Speed**: modulation speed. - **Mod Position**: sets position of modulator.