As promised, here is an additional review of Hidizs AP100 accessories and other bonus goodies that come bundled when ordered from Penonaudio (http://penonaudio.com/Hidizs-AP100).
The included leather case adds a protection for AP100 and also allows you to carry this digital audio player in style. Today it's really hard to tell apart real or fake leather, but material of this case felt genuine to me. The fitment inside of the holding sleeve was secure, not too tight or loose. It has the precise cutouts to access all the control buttons, keeps the top of the player open for HO/LO and power button, and at the bottom allows access for micro-usb cable. You also have access to SRC and EQ buttons on one side, and Lock button on the other side. The flip cover stays closed thanks to a hidden magnet, and inside there is a small velctro pocket for mico-SD card.
Btw, leather case is included with AP100 purchased from anybody, but Penon audio guys add a few additional exclusive bonuses.
As I mentioned in my original review, the headphone output jack of AP100 supports a standard TRS connection which is a problem if you are using headphones with built in in-line remote control/mic. It's not a showstopper since there is a number of adapters available to allow use of headphones with in-line remote. But additional adapters cost money and some are bulky or long-wired. Included in this package is a slim 3.5mm female to 3.5mm male adapter which I found to work great with all of my "smartphone" headphones. As a matter of fact, Penon guys sell it on ebay for $4+ shipped (http://www.ebay.com/itm/3-5mm-Female-3-5mm-Male-Headphone-Adapter-Plug-iPhone-Mobile-Phone-/290701050480?pt=US_Audio_Cables_Adapters&hash=item43af220270) for anybody who in general interested in it, but it's included for free here. I like that I don't have to worry about hanging wires, and it doesn't stick out too much.
Last but not least, they also included a pair of high quality in-ear headphones, Hisoundaudio PAA-1 model which they actually sell in their store for $20 (http://penonaudio.com/Hisoundaudio-PAA-1). Honestly, I was a bit skeptical about freebie headphones, expecting it's going to be something cheap, but was surprised to find these to sound really good!!! These are not exactly in-ear type headphones, but rather one of those iPod style, and I even put a few pictures side-by-side for a better comparison. Surprisingly, these have a nice soft cable with TPE sleeve and OFC wires. The fit was comfortable, but for some people with small ear opening it could be a problem. The sound is balanced, nothing is recessed. It has a nice punchy low-end with some sub-bass extension, great separation of mids with enough detailed clarity (great with vocals), and crisp treble extension without any hint of sibilance. One thing that surprised me the most was a super wide soundstage. I'm not gonna tell you these are giant killers that beat $100-$200 IEMs, but they sound VERY good and even for a standalone price of $20 it's a great value.
Furthermore, and to be clear these adapters below are not a part of AP100 package but definitely a good investment to have, I would like to mention about impedance adapters you can get from Penon guys ($13.90, http://penonaudio.com/3.5mm-Inpedance-Plug). As I mentioned in my review, paired up with high sensitivity headphones you are going to hear some background hissing noise listening to AP100 due to it's high output power. It's a common problem with other DAPs or AMPs as well. A solution is very simple, you need to use an impedance adapter, usually in value between 50-150 ohms. It helps to attenuate the background noise, though you also will reduce output level (will need to raise your volume up when using such adapter). Most of the adapters I have seen or own are bulky with a wire extension. In this case, you are getting a brand name DUNU impedance adapter, either 75 ohm or 150 ohm, at a very reasonable price. I have tested both with a lot of my headphones, and found that 75 ohm does a perfect job silencing the background noise without any sound quality reduction. This 3.5mm female to 3.5mm male adapter is relatively small and not going to stick out too much. It's one of those must-have accessories any audiophile should have in their tool box
