diff --git a/src/main.c b/src/main.c
index 58d427d..8f5f256 100644
--- a/src/main.c
+++ b/src/main.c
@@ -25,8 +25,12 @@ static int process(jack_nframes_t nframes, void *arg)
     jack_default_audio_sample_t *in  = (jack_default_audio_sample_t *) jack_port_get_buffer(input_port, nframes);
     jack_default_audio_sample_t *out = (jack_default_audio_sample_t *) jack_port_get_buffer(output_port, nframes);
 
-    if (in && out) {
-        memcpy(out, in, sizeof(jack_default_audio_sample_t) * nframes);
+    if (out) {
+        if (in) {
+            memcpy(out, in, sizeof(jack_default_audio_sample_t) * nframes);
+        } else {
+            memset(out, 0, sizeof(jack_default_audio_sample_t) * nframes);
+        }
     }
 
     void *midi_ctrl_buf = jack_port_get_buffer(midi_control_port, nframes);
@@ -42,19 +46,15 @@ static int process(jack_nframes_t nframes, void *arg)
                         switch (current_state) {
                             case STATE_IDLE:
                                 current_state = STATE_RECORD;
-                                fprintf(stderr, "[looper] -> record\n");
                                 break;
                             case STATE_RECORD:
                                 current_state = STATE_LOOPING;
-                                fprintf(stderr, "[looper] -> looping\n");
                                 break;
                             case STATE_LOOPING:
                                 current_state = STATE_PAUSED;
-                                fprintf(stderr, "[looper] -> paused\n");
                                 break;
                             case STATE_PAUSED:
                                 current_state = STATE_LOOPING;
-                                fprintf(stderr, "[looper] -> looping\n");
                                 break;
                         }
                     }