diff --git a/Tone/source/BufferSource.js b/Tone/source/BufferSource.js
index 2e2246e9..0cbeee44 100644
--- a/Tone/source/BufferSource.js
+++ b/Tone/source/BufferSource.js
@@ -185,7 +185,7 @@ define(["Tone/core/Tone", "Tone/core/Buffer", "Tone/source/Source", "Tone/core/G
 				if (this.curve === "linear"){
 					this._gainNode.gain.linearRampToValueAtTime(this._gain, time + fadeInTime);
 				} else {
-					this._gainNode.gain.setTargetAtTime(this._gain, time, this._gainNode.gain.getTimeConstant(fadeInTime));
+					this._gainNode.gain.exponentialAppraochValueAtTime(this._gain, time, fadeInTime);
 				}
 			} else {
 				this._gainNode.gain.setValueAtTime(gain, time);
@@ -268,7 +268,7 @@ define(["Tone/core/Tone", "Tone/core/Buffer", "Tone/source/Source", "Tone/core/G
 					if (this.curve === "linear"){
 						this._gainNode.gain.linearRampToValueAtTime(0, time);
 					} else {
-						this._gainNode.gain.setTargetAtTime(0, startFade, this._gainNode.gain.getTimeConstant(fadeOutTime));
+						this._gainNode.gain.exponentialAppraochValueAtTime(0, startFade, fadeOutTime);
 					}
 				} else {
 					this._gainNode.gain.setValueAtTime(0, time);