}
impl From<Sfxr> for Machine {
    fn from(sfxr: Sfxr) -> Self {
        Machine::new(pink() * sfxr.amp.unwrap_or(1.0) * envelope(move |t| exp(-sfxr.f * t)))
    }

            Ok(Machine::new(
                pink() * sfxr.amp.unwrap_or(1.0) * envelope(move |t| exp(-sfxr.f * t)),
            ))

            Ok(sfxr.into())

                .include_y(-1.0)
                .include_y(1.0)

                .include_y(-std::f32::consts::SQRT_2.recip())
                .include_y(std::f32::consts::SQRT_2.recip())

    amp: Some(0.2),
    f: 0.1,

    // amp: Some(0.2),
    f: 1.0,