Already the sound gains in power, the gain is stronger and more dynamic as the headphone jack of the iPhone. Then the sound quality is fabulous, bass, treble and midrange are much better!
The connectors are gold plated, cable is sturdy and the whole product is well made.
As against the cable is short, 8 cm, so I am obliged to add a small extension jack.
Very good result, I thought having to add an amp from the same manufacturer and finally this simple connectivity (considered as mere accessory from the manufacturer's website) enough.