Just did mine last night. Used a Dayton Audio 3.5 mm to RCA interconnect. Cut off the RCA and re-soldered to headphone driver with Kester %4 silver lead free solder. I changed because i wanted a longer and thicker straight cable vs. the coiled one that came on it. I chose 7 ft and it worked out great. Tighter bass without dropout and better mid response. It could be my attentive listening but I'm hearing highs I've never heard before.
DAC/AMP:Topping TP31 (2 Channel, 24 bit, 192k)
Music: :PANTyRAID (Too Fine to do Time), Opeth (Bleak), Claude Debussy (String Quartet No.1 In G Minor, Op. 10: I. Anime Et Tres Decide), God Speed You! Black Emperor ( Blaise Bailey Finnegan III).
I had great success with mine. I recommend if you have a better cable and good solder.