Some ditital volume control IC have very good SQ. and the cost is not problem too. but there are some reason let us select the traditional volume control (potentionmeter)
1, the operation experience from a smooth volume control and the direct indication to the volume.
2, VS the digital volume control IC, potentionmeter is a passive component that means there are not distortion, and the best digital volume control still have some distortion.
3, E11 have a protector on the knob, so it is very safe to put it into your pocket, and the diameter of the knob is very small, that means you need bigger strength to turn it.
James from FiiO