Hello all, still waiting for time to pass and ask for full refund from NiceHCK, because I've not received my A4s since 20th Dec...
On the other hand (and what really matters here), due to this, I "have been forced" somehow to continue using CH9Ts as my all-day iems (120+ hours now) and, don't know if my ears are now more used to them, or they have really burned-in someway, but I feel that everything has improved (clearly perceptible to me) a bit. I swear I can hear difference and all is a bit better. Soundstage, definition, signature is... Don't know how to say it, but my feeling is as the sound signature is now on version 1.1, more mature? Rounder? Don't know. Is the same sound, but a bit better. I've lost the little "messie" feeling I had, when listening to dense songs at high volumes (Rock/metal mainly, with other genres didn't remember to have that feeling). Cimbals are now more clear and defined at lower volumes too.
I continue thinking that a "bit" of a good eq, helps to make them shine to 100% but I absolutely love their sound "naked" too.
I've tested them with Sony SBH50 (bluetooth Radio/AMP) and GGMM A1 (USB cheap AMP) and a couple of cables and nothing bad nor good can be said roughly. Silver plated cable turns them quiet noticeably brighter, and sound is pretty nice, but I like more stock sound. I play flac 16bit 44.1khz files mainly, and use Galaxy S6 exynos internal DAC (UHQA PCM) 75% of the time plus Poweramp Alpha 3.
Wanted to share, mainly, because I think that nobody can go wrong getting a pair of these except, maybe, for very specific cases or bigger budgets, having more choices.