I recently got the Truth Copper cable on loan from Dita, and I must say I quite like it.
The Copper has good low-end extension, paired with an attenuated bass response. This might be a turn off for some people, but it works wonders on its presentation. The Copper creates a spacious stage both in width and depth, resulting in a nice 3D stage. The laid-back bass results in a particularly airy stage, enhancing the spacious feel of the stage. Accordingly, the separation is very good, as well as its midrange transparency. In accordance with the bass quantity, the lower midrange is laid-back. However, the balance between the centre and upper midrange is very good, and because of this linear relation its tone is quite accurate, especially since the treble is not enhanced. It's lightly warm, but not overly so. Clear, but not bright. This works especially well for iems that suffer from the common upper midrange dip, which tends to 'dull' their tone.
So, how this translates to sound is a neutral note size, that isn't overly thick in accordance with the laid-back bass. Similarly, vocals are not overly full or forward. However, the balance in their articulation is very good; the range between depth and pronunciation. As a result of the large and airy stage, the presentation is very clean and organised, even more so because of the compact note size. It's a detailed image based on separation, without having to resort to a brighter treble. And the instrument tone is very realistic, resulting in what I feel is a beautiful sound. Not overly warm, just accurate. It's a type of signature that might not appeal to bass-heads, but more so to people that value a great stage and general presentation, both in terms of dimensions and quality. Within that stage, instruments have a realistic tone as well as good transparency.
