diff --git a/src/plugins/score-plugin-fx/Fx/Arraymap.hpp b/src/plugins/score-plugin-fx/Fx/Arraymap.hpp
index 23c144e7e9..40334601f8 100644
--- a/src/plugins/score-plugin-fx/Fx/Arraymap.hpp
+++ b/src/plugins/score-plugin-fx/Fx/Arraymap.hpp
@@ -27,6 +27,7 @@ struct Node
     {
       // Messages to this port trigger a new computation cycle with updated timestamps
       halp_flag(active_port);
+      void update(Node& self) { self.trigger = true; }
     } port;
     halp::lineedit<"Expression", "x"> expr;
   } inputs;
@@ -74,11 +75,14 @@ struct Node
     int64_t last_value_time{};
     std::string last_expression;
   } state;
+  bool trigger{false};
 
   using tick = halp::tick_flicks;
 
   void operator()(const tick& tk)
   {
+    if(!std::exchange(trigger, false))
+      return;
     GenericMathMapping<State>::run_polyphonic(
         inputs.port.value, outputs.port.call, inputs.expr.value, tk, state);
   }
diff --git a/src/plugins/score-plugin-fx/Fx/MathValueFilter.hpp b/src/plugins/score-plugin-fx/Fx/MathValueFilter.hpp
index 0bc69d3829..2885d31272 100644
--- a/src/plugins/score-plugin-fx/Fx/MathValueFilter.hpp
+++ b/src/plugins/score-plugin-fx/Fx/MathValueFilter.hpp
@@ -30,6 +30,7 @@ struct Node
     {
       // Messages to this port trigger a new computation cycle with updated timestamps
       halp_flag(active_port);
+      void update(Node& self) { self.trigger = true; }
     } port;
     halp::lineedit<"Expression (ExprTK)", "cos(t) + log(pos * (1+abs(x)) / dt)"> expr;
     halp::hslider_f32<"Param (a)", halp::range{0., 1., 0.5}> a;
@@ -102,10 +103,13 @@ struct Node
   } state;
 
   halp::setup setup;
+  bool trigger{false};
   void prepare(halp::setup s) { setup = s; }
 
   void operator()(const tick& tk)
   {
+    if(!std::exchange(trigger, false))
+      return;
     auto& self = this->state;
     if(!self.expr.set_expression(this->inputs.expr))
       return;
diff --git a/src/plugins/score-plugin-fx/Fx/MicroMapping.hpp b/src/plugins/score-plugin-fx/Fx/MicroMapping.hpp
index de5a42960f..98c303f4ad 100644
--- a/src/plugins/score-plugin-fx/Fx/MicroMapping.hpp
+++ b/src/plugins/score-plugin-fx/Fx/MicroMapping.hpp
@@ -24,7 +24,9 @@ struct Node
     struct : halp::val_port<"in", ossia::value>
     {
       // Messages to this port trigger a new computation cycle with updated timestamps
+      // FIXME not implemented yet
       halp_flag(active_port);
+      void update(Node& self) { self.trigger = true; }
     } port;
     halp::lineedit<"Expression", "x / 127"> expr;
   } inputs;
@@ -76,12 +78,15 @@ struct Node
   } state;
 
   halp::setup setup;
+  bool trigger{false};
   void prepare(halp::setup s) { setup = s; }
 
   using tick = halp::tick_flicks;
 
   void operator()(const tick& tk)
   {
+    if(!std::exchange(trigger, false))
+      return;
     auto& self = this->state;
     if(!self.expr.set_expression(this->inputs.expr))
       return;
diff --git a/src/plugins/score-plugin-fx/Fx/Smooth.hpp b/src/plugins/score-plugin-fx/Fx/Smooth.hpp
index 4ae87970f4..aa5aaeac11 100644
--- a/src/plugins/score-plugin-fx/Fx/Smooth.hpp
+++ b/src/plugins/score-plugin-fx/Fx/Smooth.hpp
@@ -32,6 +32,7 @@ struct Node : NoiseState
     {
       // Messages to this port trigger a new computation cycle with updated timestamps
       halp_flag(active_port);
+      void update(Node& self) { self.trigger = true; }
     } port;
     halp::enum_t<dno::type, "Type"> type;
     halp::knob_f32<"Amount", halp::range{0., 1., 0.1}> amount;
@@ -43,9 +44,12 @@ struct Node : NoiseState
   {
     value_out port{};
   } outputs;
+  bool trigger{false};
 
   void operator()()
   {
+    if(!std::exchange(trigger, false))
+      return;
     auto& v = this->inputs.port.value;
 
     auto filtered = this->filter(
diff --git a/src/plugins/score-plugin-fx/Fx/VelToNote.hpp b/src/plugins/score-plugin-fx/Fx/VelToNote.hpp
index 0b68dc7203..7e93b8ed3e 100644
--- a/src/plugins/score-plugin-fx/Fx/VelToNote.hpp
+++ b/src/plugins/score-plugin-fx/Fx/VelToNote.hpp
@@ -74,6 +74,7 @@ struct Node
   {
     Note note{};
     int64_t date{};
+    bool fresh{};
   };
   std::vector<NoteIn> to_start;
   std::vector<NoteIn> running_notes;
@@ -166,21 +167,25 @@ struct Node
       auto note = in.value.apply(val_visitor{*this, base_note, base_vel});
 
       if(rand_note != 0)
-        note.pitch += rnd::rand(-rand_note, rand_note);
+        note.pitch = std::clamp(
+            (int)note.pitch + (int)rnd::rand(-rand_note, rand_note), 0, 127);
+
       if(rand_vel != 0)
-        note.vel += rnd::rand(-rand_vel, rand_vel);
+        note.vel
+            = std::clamp((int)note.vel + (int)rnd::rand(-rand_vel, rand_vel), 0, 127);
 
       note.pitch = ossia::clamp((int)note.pitch + shiftnote, 0, 127);
       note.vel = ossia::clamp((int)note.vel, 0, 127);
 
-      if(note.vel != 0)
+      if(note.vel != 0.)
       {
         if(start == 0.f) // No quantification, start directly
         {
           outputs.midi.note_on(chan, note.pitch, note.vel).timestamp = in.timestamp;
           if(end > 0.f)
           {
-            this->running_notes.push_back({note, tk.position_in_frames + in.timestamp});
+            this->running_notes.push_back(
+                {note, tk.position_in_frames + in.timestamp, true});
           }
           else if(end == 0.f)
           {
@@ -189,7 +194,10 @@ struct Node
             outputs.midi.note_off(chan, note.pitch, note.vel).timestamp = in.timestamp;
 #endif
           }
-          // else do nothing and just wait for a note off
+          else
+          {
+            // else do nothing and just wait for a note off
+          }
         }
         else
         {
@@ -270,11 +278,21 @@ struct Node
 
   void stop_notes(ossia::physical_time date_phys, int chan)
   {
-    for(auto& note : this->running_notes)
+    for(auto it = this->running_notes.begin(); it != this->running_notes.end();)
     {
-      outputs.midi.note_off(chan, note.note.pitch, note.note.vel).timestamp = date_phys;
+      auto& note = *it;
+      if(!note.fresh)
+      {
+        it = this->running_notes.erase(it);
+        outputs.midi.note_off(chan, note.note.pitch, note.note.vel).timestamp
+            = date_phys;
+      }
+      else
+      {
+        note.fresh = false;
+        ++it;
+      }
     }
-    this->running_notes.clear();
     /*
     for(auto it = this->running_notes.begin(); it != this->running_notes.end();)
     {