I'm in the same situation. i sent her my E-Series cable for repair and i haven't had response since february. But if you ask for a new cable, he will reply quickly. This seller is unreliable. Not recommended!
Now i have a amplified by Leben CS300XS speaker amplifier + Woo Audio WEE energeizer. I'm very satisfied. But i would like to listen them in its maximum power.
What are best amplifiers for this headphone? That benefit it.
PD: The BHSE or WES are too expensive . Like a Stax T1, T2, 717, 727, KGSHV, GES, LL, ....