diff --git a/cpp/src/dx7note.cc b/cpp/src/dx7note.cc
index 9e775a7..bddab1e 100644
--- a/cpp/src/dx7note.cc
+++ b/cpp/src/dx7note.cc
@@ -50,11 +50,13 @@ int32_t osc_freq(int midinote, int mode, int coarse, int fine, int detune) {
       // (1 << 24) / log(2)
       logfreq += (int32_t)floor(24204406.323123 * log(1 + 0.01 * fine) + 0.5);
     }
-    // TODO: detune
+    // This was measured at 7.213Hz per count at 9600Hz, but the exact
+    // value is somewhat dependent on midinote. Close enough for now.
+    logfreq += 12606 * (detune - 7);
   } else {
     // ((1 << 24) * log(10) / log(2) * .01) << 3
-     logfreq = (4458616 * ((coarse & 3) * 100 + fine)) >> 3;
-    // TODO: detune
+    logfreq = (4458616 * ((coarse & 3) * 100 + fine)) >> 3;
+    logfreq += detune > 7 ? 13457 * (detune - 7) : 0;
   }
   int32_t base_freq = Freqlut::lookup(logfreq);
   return base_freq;
@@ -122,8 +124,7 @@ int ScaleLevel(int midinote, int break_pt, int left_depth, int right_depth,
   }
 }
 
-// Considering making this an init method...
-Dx7Note::Dx7Note(const char bulk[128], int midinote, int velocity) {
+void Dx7Note::init(const char bulk[128], int midinote, int velocity) {
   char patch[156];
   UnpackPatch(bulk, patch);  // TODO: move this out, take unpacked patch
   for (int op = 0; op < 6; op++) {
@@ -135,6 +136,7 @@ Dx7Note::Dx7Note(const char bulk[128], int midinote, int velocity) {
       levels[i] = patch[off + 4 + i];
     }
     int outlevel = patch[off + 16];
+    outlevel = Env::scaleoutlevel(outlevel);
 #ifdef VERBOSE
     for (int j = 8; j < 12; j++) {
       cout << (int)patch[off + j] << " ";
@@ -143,7 +145,7 @@ Dx7Note::Dx7Note(const char bulk[128], int midinote, int velocity) {
     int level_scaling = ScaleLevel(midinote, patch[off + 8], patch[off + 9],
         patch[off + 10], patch[off + 11], patch[off + 12]);
     outlevel += level_scaling;
-    outlevel = min(99, outlevel);
+    outlevel = min(127, outlevel);
 #ifdef VERBOSE
     cout << op << ": " << level_scaling << " " << outlevel << endl;
 #endif
diff --git a/cpp/src/dx7note.h b/cpp/src/dx7note.h
index 34bb00b..da0bb1d 100644
--- a/cpp/src/dx7note.h
+++ b/cpp/src/dx7note.h
@@ -31,7 +31,7 @@ class Dx7Note {
   // Interesting question: should the setup be in the constructor, or should
   // there be an init method? The latter would make it easier to use a fixed
   // pool of note objects.
-  Dx7Note(const char patch[128], int midinote, int velocity);
+  void init(const char patch[128], int midinote, int velocity);
 
   // Note: this _adds_ to the buffer. Interesting question whether it's
   // worth it...
diff --git a/cpp/src/env.cc b/cpp/src/env.cc
index 65b736c..cb9e335 100644
--- a/cpp/src/env.cc
+++ b/cpp/src/env.cc
@@ -73,16 +73,19 @@ void Env::setparam(int param, int value) {
 }
 
 const int levellut[] = {
-  0, 2, 4, 6, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22
+  0, 5, 9, 13, 17, 20, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41, 42, 43, 45, 46
 };
 
+int Env::scaleoutlevel(int outlevel) {
+  return outlevel >= 20 ? 28 + outlevel : levellut[outlevel];
+}
+
 void Env::advance(int newix) {
   ix_ = newix;
   if (ix_ < 4) {
     int newlevel = levels_[ix_];
-    int actuallevel = newlevel >= 19 ?
-      14 + (newlevel >> 1) : levellut[newlevel];
-    actuallevel = (actuallevel << 6) + outlevel_ - 3360;
+    int actuallevel = scaleoutlevel(newlevel) >> 1;
+    actuallevel = (actuallevel << 6) + outlevel_ - 4256;
     actuallevel = actuallevel < 16 ? 16 : actuallevel;
     // level here is same as Java impl
     targetlevel_ = actuallevel << 16;
diff --git a/cpp/src/env.h b/cpp/src/env.h
index 20e2d5c..d76dc06 100644
--- a/cpp/src/env.h
+++ b/cpp/src/env.h
@@ -39,6 +39,7 @@ class Env {
 
   void keydown(bool down);
   void setparam(int param, int value);
+  static int scaleoutlevel(int outlevel);
  private:
   int rates_[4];
   int levels_[4];
diff --git a/cpp/src/fm_core.cc b/cpp/src/fm_core.cc
index a6ebe1d..3c95cb0 100644
--- a/cpp/src/fm_core.cc
+++ b/cpp/src/fm_core.cc
@@ -109,6 +109,7 @@ void FmCore::dump() {
 
 void FmCore::compute(int32_t *output, FmOpParams *params, int algorithm,
                      int32_t *fb_buf, int feedback_shift) {
+  const int kLevelThresh = 1120;
   const FmAlgorithm alg = algorithms[algorithm];
   bool has_contents[3] = { true, false, false };
   for (int op = 0; op < 6; op++) {
@@ -120,7 +121,7 @@ void FmCore::compute(int32_t *output, FmOpParams *params, int algorithm,
     int32_t *outptr = (outbus == 0) ? output : buf_[outbus - 1].get();
     int32_t gain1 = param.gain[0];
     int32_t gain2 = param.gain[1];
-    if (gain1 != 0 || gain2 != 0) {
+    if (gain1 >= kLevelThresh || gain2 >= kLevelThresh) {
       if (!has_contents[outbus]) {
         add = false;
       }
diff --git a/cpp/src/synth_unit.cc b/cpp/src/synth_unit.cc
index f024d0a..946150c 100644
--- a/cpp/src/synth_unit.cc
+++ b/cpp/src/synth_unit.cc
@@ -44,9 +44,10 @@ char epiano[] = {
 SynthUnit::SynthUnit(RingBuffer *ring_buffer) {
   ring_buffer_ = ring_buffer;
   for (int note = 0; note < max_active_notes; ++note) {
-    active_note_[note].dx7_note = NULL;
+    active_note_[note].dx7_note = new Dx7Note;
     active_note_[note].keydown = false;
     active_note_[note].sustained = false;
+    active_note_[note].live = false;
   }
   input_buffer_index_ = 0;
   memcpy(patch_data_, epiano, sizeof(epiano));
@@ -117,13 +118,13 @@ int SynthUnit::ProcessMidiMessage(const uint8_t *buf, int buf_size) {
       // note on
       int note_ix = AllocateNote();
       if (note_ix >= 0) {
-        delete active_note_[note_ix].dx7_note;
         active_note_[note_ix].midi_note = buf[1];
         active_note_[note_ix].keydown = true;
         active_note_[note_ix].sustained = sustain_;
+        active_note_[note_ix].live = true;
         const uint8_t *patch = patch_data_ + 128 * current_patch_;
-        active_note_[note_ix].dx7_note =
-          new Dx7Note((const char *)patch, buf[1], buf[2]);
+        active_note_[note_ix].dx7_note->init(
+          (const char *)patch, buf[1], buf[2]);
       }
       return 3;
     }
@@ -218,7 +219,7 @@ void SynthUnit::GetSamples(int n_samples, int16_t *buffer) {
       audiobuf.get()[j] = 0;
     }
     for (int note = 0; note < max_active_notes; ++note) {
-      if (active_note_[note].dx7_note != NULL) {
+      if (active_note_[note].live) {
         active_note_[note].dx7_note->compute(audiobuf.get());
       }
     }
diff --git a/cpp/src/synth_unit.h b/cpp/src/synth_unit.h
index 31cea4f..a484000 100644
--- a/cpp/src/synth_unit.h
+++ b/cpp/src/synth_unit.h
@@ -22,6 +22,7 @@ struct ActiveNote {
   int midi_note;
   bool keydown;
   bool sustained;
+  bool live;
   Dx7Note *dx7_note;
 };