diff --git a/firmware/polyvec-hal/src/gw.rs b/firmware/polyvec-hal/src/gw.rs
index ab00b93..68e6863 100644
--- a/firmware/polyvec-hal/src/gw.rs
+++ b/firmware/polyvec-hal/src/gw.rs
@@ -29,6 +29,7 @@ pub trait WavetableOscillator {
 pub trait PitchShift {
     fn set_pitch(&self, value: FixedI32<U16>);
     fn pitch(&self) -> FixedI32<U16>;
+    fn set_window_sz(&self, value: u16);
 }
 
 pub trait KarlsenLpf {
@@ -132,6 +133,11 @@ macro_rules! pitch_shift {
             fn pitch(&self) -> FixedI32<U16> {
                 FixedI32::<U16>::from_bits(self.csr_pitch().read().bits() as i32)
             }
+            fn set_window_sz(&self, value: u16) {
+                unsafe {
+                    self.csr_window_sz().write(|w| w.csr_window_sz().bits(value));
+                }
+            }
         })+
     };
 }
diff --git a/firmware/polyvec-lib/src/opt.rs b/firmware/polyvec-lib/src/opt.rs
index 8ec304c..389383e 100644
--- a/firmware/polyvec-lib/src/opt.rs
+++ b/firmware/polyvec-lib/src/opt.rs
@@ -70,7 +70,7 @@ pub struct AdsrOptions {
 #[derive(Clone)]
 pub struct ScopeOptions {
     pub selected: Option<usize>,
-    pub delay_len: NumOption<u32>,
+    pub grain_sz: NumOption<u32>,
     pub trig_lvl: NumOption<i32>,
     pub trig_sns: NumOption<i32>,
 }
@@ -110,7 +110,7 @@ impl_option_view!(AdsrOptions,
                   attack_ms, decay_ms, release_ms, resonance);
 
 impl_option_view!(ScopeOptions,
-                  delay_len, trig_lvl, trig_sns);
+                  grain_sz, trig_lvl, trig_sns);
 
 impl_option_view!(TouchOptions,
                   note_control, led_mirror);
@@ -167,12 +167,12 @@ impl Options {
             },
             scope: ScopeOptions {
                 selected: None,
-                delay_len: NumOption{
-                    name: "delayln".into(),
-                    value: 511,
+                grain_sz: NumOption{
+                    name: "grainsz".into(),
+                    value: 1023,
                     step: 1,
-                    min: 128,
-                    max: 511,
+                    min: 512,
+                    max: 1023,
                 },
                 trig_lvl: NumOption{
                     name: "trig lvl".into(),
diff --git a/firmware/polyvec/src/main.rs b/firmware/polyvec/src/main.rs
index 36d7ff5..5d8cd7f 100644
--- a/firmware/polyvec/src/main.rs
+++ b/firmware/polyvec/src/main.rs
@@ -253,7 +253,6 @@ impl State {
             }
         }
 
-        /*
         if opts.touch.note_control.value == opt::NoteControl::Midi {
             while let Ok(event) = self.midi_in.read() {
                 self.voice_manager.event(event, uptime_ms);
@@ -261,12 +260,12 @@ impl State {
             self.voice_manager.tick(uptime_ms, opts);
             for n_voice in 0..N_VOICES {
                 let voice = &self.voice_manager.voices[n_voice];
-                shifter[n_voice].set_pitch(voice.pitch);
-                lpf[n_voice].set_cutoff((voice.amplitude * 8000f32) as i16);
-                lpf[n_voice].set_resonance(opts.adsr.resonance.value);
+                shifter[n_voice].set_pitch(FixedI32::<U16>::from_num(voice.pitch));
+                shifter[n_voice].set_window_sz(opts.scope.grain_sz.value as u16);
+                lpf[n_voice].set_cutoff(FixedI32::<U16>::from_num(voice.amplitude));
+                lpf[n_voice].set_resonance(FixedI32::<U16>::from_num(0));
             }
         } else {
-        */
             let pmod1 = &peripherals.EURORACK_PMOD1;
             let pmod2 = &peripherals.EURORACK_PMOD2;
             let pmod3 = &peripherals.EURORACK_PMOD3;
@@ -302,6 +301,7 @@ impl State {
                 let ampl = (touch_raw as f32) / 256.0f32;
                 let pitch = note_to_pitch(midi_note);
                 shifter[n_voice].set_pitch(FixedI32::<U16>::from_num(pitch));
+                shifter[n_voice].set_window_sz(opts.scope.grain_sz.value as u16);
 
                 // Low-pass filter to smooth touch on/off
                 let ampl_old: f32 = lpf[n_voice].cutoff().to_num();
@@ -351,9 +351,7 @@ impl State {
                     update_hw_voice(n_voice, voices_old[n_voice].note, 0);
                 }
             }
-            /*
         }
-            */
 
         self.last_control_type = Some(opts.touch.note_control.value);
     }
diff --git a/rtl/dsp.py b/rtl/dsp.py
index ea9c85f..0a210eb 100644
--- a/rtl/dsp.py
+++ b/rtl/dsp.py
@@ -447,7 +447,7 @@ def __init__(self, n_lpfs=2):
 
 class LpfDecorator(Module, AutoCSR):
     def __init__(self, lpf, dw=32):
-        self.csr_g = CSRStorage(dw, reset=Constant(float_to_fp(1.0), (32, True)))
+        self.csr_g = CSRStorage(dw, reset=Constant(float_to_fp(0.0), (32, True)))
         self.csr_resonance = CSRStorage(dw, reset=Constant(float_to_fp(0.0), (32, True)))
         self.comb += [
                 lpf.g.eq(self.csr_g.storage),