“The HD330 in stock version is a decent headphone but …”
Upgrading for Beyer DT770 pads and Headband is a step up in the search of a confortable headphone.
Not only adding comfort and a better feeling during use the DT770 velour pads adds also more distance to the drivers and improves the soundstage.
The new cable is longer and use better connectors and solder joint (silver) . The result is a better separation of the instruments and also a more beautiful mid and treble range. The low mids bass benefits also a little but its less obvious like adding just a litte more definition.
On the stock headphone mids sounds like a bit congested and charged. The bass response is also a little bit too much forward due to this lack of precision.
To conclude I would recommend the pads and cable mod to improve the sound of this headphone that I consider one of the best buy actually on the market in this price range.