I have my first impressions posted on 10/7/17 in the CanJam impressions thread, around page 5. I have added more thoughts today.
https://www.head-fi.org/threads/can...2017-impressions.862096/page-13#post-13773816
also written in reaction to this
http://www.androidauthority.com/no-headphone-jacks-bad-idea-opinion-805797/
For those who didn't visit my link above, here is a cross-post of my first impressions below - I haven't had time to listen a lot since RMAF, but have noticed that the background is dead silent with all of my custom Westone and JHAudio IEM, unless I go into high-gain AND also turn up the volume. That's pretty good. My first impressions were with full size headphones like Edition-X and Mr Speakers Ether C Flow and Aeon Closed, but now I have also added IEM to the testing, and I'm still blown away.
--- October 9, 2017 ---
So, I found and read this article today
http://www.androidauthority.com/no-headphone-jacks-bad-idea-opinion-805797/ about more phones losing headphone jacks with little gains in return.
The timing couldn't be any better. I just bought the
CEntrance BlueDAC at RMAF for myself and my son to combat this switch to bluetooth everything, with lack of headphone jacks becoming more prevalent in modern cell phones. See
https://www.centrance.com/products/bluedac/ for more information.
This CEntrance BlueDAC will act as a bridge to connect almost any kind of headphone to my iPhone 7+ (and other cell phones in the future). The wired sound quality was indistinguishable with my wired DACportable (with DSD and 32/384 decoding via USB), and the wireless sound quality with it's upsampling is stunning and difficult to discern from wired playback. This despite the iPhone using AAC over bluetooth and not the AptX-HD codec.
It uses the AK4490 DAC, and a class-A headphone amplifier with digital volume control. It has a Li-Planet Ocean battery for wireless operation, with up to 20 hours of battery life. I neglected to find out if it draws power from the iPhone when used with a USB camera connection kit. It's made of a lightweight plastic case instead of their previous heavy CNC cases, so it's easier to carry. The outputs are a 3.5mm stereo jack and a 2.5mm balanced TRS jack.
The sound quality of the BlueDAC with our HiFiMan Edition-X was simply outstanding. The bass impact we experienced was totally unexpected and welcome, but the broad and open soundstage and transparency was even more welcome. It's got plenty of power to drive the Mr Speakers Ether Flow open headphones, which are a few dB less efficient. It can also drive the HiFiMan Sundara, which are a bit less efficient than our Edition-X. In low gain mode, it worked very well with my Westone ES60 custom IEM, with a very low noise floor.
The BlueDAC was one of the YOU MUST HAVE purchases to consider this year.
Other items that are on our highly recommended list are the HiFiMan HE-1000 mk2 and Edition-X and Sundara, Audioengine HD6 and also their B1 DAC and D2 DAC, PS Audio Perfectwave DSD DAC, Stax SR-009 with Headamp Blue Hawaii, Headamp GS-X and Gilmore Lite, Focal Utopia headphones, Mr Speakers Ether C Flow, Audeze LCD-3, Foster TH900 mk2, Sennheiser 820 balanced amp and HD-800S headphones, Westone W60 or W80 or ES60 IEM, and JH 16Pro V2 or Roxanne, Focal Sopra No.3 speakers, and PSB subseries 450 subwoofer. I also encouraged CEntrance to bring back the HiFi-M8 at a more affordable or attractive price.