I had been running with the stock AB1266 Phi TC headphone cable since I bought the headphones new from Abyss about 3 months ago. Recently, I had my Norne Vykari Reference headphone cables re-terminated by Norne (thanks, Trevor) for the 1266 and swapped them in.
Edit: Vykari is a hybrid, silver/copper cable: 17.3awg we have a large 18.9awg as silver occ litz per polarity, with the remaining as 22awg copper occ litz.
My findings, Vykari as compared to the stock cable, with Vykari:
1. Mids are pushed more forward in the mix, more prominent.. With the stock cable, the mids are comparatively more recessed or set back in the mix.
2. Undeniable improvement in the depth of the soundstage and layering aspects, holography.
3. Improved detail and recording room or venue info retrieval. The tiniest, microscopic details are more noticeable. Importantly, the improved detail is presented in a natural/realistic manner. There is a shimmering/lit from within quality, and not fatiguing or bright at all. The stock cable leans a bit hot/hard, less realistic.
4.
Much improved tonal characteristics.. overall instruments sound quite a bit more like the real thing.
5. Fuller, more visceral, smoother analog type sound. It is hard to pull off "smooth and natural/realistic warmth" plus "hyper detailed and revealing" as a sonic combo, but here we have both!
6. Overall, a more immersive experience and the instruments and vocals just have a higher degree of presence, realism.
a very worthwhile improvement, and I was already happy with the 1266 with the stock cable.