diff --git a/synth/triplex.h b/synth/triplex.h
index 2975006..c673e10 100644
--- a/synth/triplex.h
+++ b/synth/triplex.h
@@ -327,8 +327,17 @@ struct tx_state {
 	tx_operator op3;
 };
 
+inline void tx_voice_init(tx_state& s, double samplerate)
+{
+	tx_sineosc_init(s.feedback_osc, samplerate);
+	tx_envelope_init(s.pitch_env, samplerate);
+	tx_operator_init(s.op1, samplerate);
+	tx_operator_init(s.op2, samplerate);
+	tx_operator_init(s.op3, samplerate);
+}
+
 inline void tx_voice_process_block(tx_state& t, voice_state& s, float** audio, size_t num_frames,
-								   const vector<audio_buffer<float>>& mods)
+								   const vector<audio_buffer<float>>& mods = {})
 {
 	float frequency = midi_to_frequency(s.midi_note + t.pitch_mod + t.additional_pitch_mod);
 
@@ -517,12 +526,20 @@ struct tx_synth {
 	array<tx_state, MAX_VOICES> voices;
 };
 
-inline void tx_synth_process_block(tx_synth& s, float** audio, size_t num_frames, const vector<midi_event>& midi_events,
-								   const vector<audio_buffer<float>>& mods)
+inline void tx_synth_init(tx_synth& s, double samplerate)
 {
+	voice_allocator_init(s.allocator);
+	for (int i = 0; i < MAX_VOICES; i++) { tx_voice_init(s.voices[i], samplerate); }
+}
+
+inline void tx_synth_process_block(tx_synth& s, float** audio, size_t num_frames, const vector<midi_event>& midi_events,
+								   const vector<audio_buffer<float>>& mods = {})
+{
+	for (int i = 0; i < num_frames; i++) { audio[0][i] = audio[1][i] = 0.f; } // clear audio buffers
+
 	voice_allocator_process_block(s.allocator, midi_events);
 
-	for (int i = 0; i < MAX_VOICES; i++) {
+	for (int i = 0; i < s.allocator.active_voice_count; i++) {
 		tx_voice_process_block(s.voices[i], s.allocator.voices[i], audio, num_frames, mods);
 	}
 }
@@ -726,4 +743,9 @@ inline void tx_apply_parameter_mapping(array<tx_state, MAX_VOICES>& v, tx_parame
 	}
 }
 
+inline void tx_apply_parameter_mappings(array<tx_state, MAX_VOICES>& v, std::vector<tx_parameter_mapping>& m,
+										float value)
+{
+	for (int i = 0; i < m.size(); i++) { tx_apply_parameter_mapping(v, m[i], value); }
+}
 } // namespace trnr
diff --git a/synth/voice_allocator.h b/synth/voice_allocator.h
index c2c7ff3..23f17af 100644
--- a/synth/voice_allocator.h
+++ b/synth/voice_allocator.h
@@ -61,10 +61,10 @@ inline void make_mod_wheel(midi_event& ev, double _mod, int _offset = 0)
 
 struct voice_state {
 	int midi_note;
-	bool is_busy;
-	bool gate;
-	bool trigger;
-	float velocity;
+	bool is_busy = false;
+	bool gate = false;
+	bool trigger = false;
+	float velocity = 0.0f;
 	array<midi_event, MAX_EVENTS_PER_VOICE> events;
 	size_t event_count = 0;
 };
@@ -132,7 +132,7 @@ inline void voice_process_event_for_frame(voice_state& v, size_t frame)
 {
 	const midi_event* best_event = nullptr;
 
-	for (int i = 0; i < v.events.size(); i++) {
+	for (int i = 0; i < v.event_count; i++) {
 		const midi_event& ev = v.events[i];
 		if (ev.offset == frame) {
 			best_event = &ev;