Sane values for filter

voice.c

@@ -17,8 +17,8 @@ static inline void voice_tick(struct voice_t *voice)
 	voice->sample++;
 }
 
-static double _R = 2.7;
-static double _C = 4.3;
+static double _R = 4700.0;
+static double _C = 0.000000047;
 
 static inline void voice_filter(struct voice_t *voice, float l, float r)
 {
@@ -53,8 +53,8 @@ void voice_run(struct voice_t *voice, uint32_t samples, float *left, float *righ
 	amplitude = env_getamplitude(&_env2, voice->sample, voice->released) * voice->velocity * voice->velocity * 1.5;
 
 	if (amplitude > 0.0) {
-		l *= voice->osc[1].tri * (1.0 + voice->osc[2].sin * 0.25);
-		r *= voice->osc[1].tri * (1.0 + voice->osc[2].sin * 0.25);
+		l += amplitude * voice->osc[1].tri * (1.0 + voice->osc[2].sin * 0.25);
+		r += amplitude * voice->osc[1].tri * (1.0 + voice->osc[2].sin * 0.25);
 	}
 
 	voice_filter(voice, l, r);