My setup: ATH-W1000X headphones, and ATH-CKR10 earphones. I have a Fiio E17K as my DAC/Amp. I plug in my W1000X/CKR10 into the headphone jack of the E17K, then I use a cable from the aux jack of the E17K into the lightning adapter which goes into my iPhone XR.

My issue: High noise floor. No matter what configuration I use, where I plug stuff in (iPhone, desktop PC, MacBook, etc.), with the amp, without the amp, etc., with my CKR10 and W1000X, there is an audible and distracting floor. That said, CKR10/W1000X straight into iPhone XR has much less noise. It seems like the E17K is adding its own noise, even though I set gain to +0 db!

Also The XR contributes its own noise outside of the playback of recordings. After I've turned off music, there is still some audio signal for a few seconds until it shuts off completely and during that time you can tell there is a modest amount of noise. Then, when I turn on music, there is even more noise from the recording itself. So there are two layers of audibly loud noise any time I listen to music.

At this point I'm pretty sure I want to sell my CKR10 (and maybe the E17K), and get the Massdrop Plus IEM.

So, question 1: What can I do to fix the noise floor for my W1000X? (Forget the CKR10, I'm selling that).

Question 2: What can I do to prevent a noise floor issue with the Massdrop Plus I am buying soon?