It’s this one, cheap and it does its job
NewFantasia HiFi Cable with 2.5mm Trrs Balanced Male Compatible with Sennheiser HD598 / HD598 SE / HD598 Cs / HD599 / HD569 / HD579 Headphones and for Astell&Kern AK240 AK380 AK320 onkyo DP-X1 FIIO
https://www.amazon.com/dp/B075C9HXW...abc_WEMHBWM9ZASQFX2X5T68?_encoding=UTF8&psc=1
here is a closer look, I somehow managed to simply tie those together using the cable
Not the sleekest look, but it’s the thing that exists.
Great point is that it’s 2.5mm balanced, so BTR5 can run the HD560S with 250mw(vs SE 80mw) with dual DAC, headphones do need power and this is how we can run LDAC or AptX HD with balanced power
Many wireless headphones does not have volume control but with this, you can adjust volume, play/pause/skip/back, change lowpass filter without touching the main device which is wonderful.
-Lightweight compared to HD6xx series due to its plastic body; made it easier to use as wireless can
-Newly developed 120-ohm transducer used, easier to drive with smaller daps/amps
-Single-sided connector,compared to double-sided connector with HD6xx series, made it easier to mod to wireless