[General Accessories] vectron:
This is a review of Hidizs AP100 portable HiFi music player. http://penonaudio.com/Hidizs-AP100 (manufacturer website: http://www.hidizs.com/EN/Products/Audio Players/AP100.html)

It takes a lot of confidence to enter a market of portable DAPs (digital audio players) considering the latest sophomore releases from FiiO and iBasso as well as a few other budget audio players. And that's exactly what I found with a freshman release from Hidizs, a new kid on the block that decided to make a bold statement with their first release. Everything from the packaging to the build quality and selection of components indicates they did their homework studying competition to match the level of finesse and also to come up with a few of their own tricks to distinguish themselves from the crowd. Let's take a closer look at what I found after spending the last few days testing Hidizs AP100.

Packaging / Unboxing

Taking a page right out of HiFiMAN book, AP100 arrived in a very elegant formal attire of a black box with a silver print of the company/model on the front and detailed spec in Chinese and English on the back. As you remove the outer sleeve, and slide out the inner tray, you see a form fitting cutout opening with AP100 wrapped in ESD bag (a similar detail I have seen in the past with HM700). Beside audio player, the included accessories are usb to micro-usb cable for charging and data transfer, a short 3.5mm male to male patch cable for connecting Line Out to external amp, a 3.5mm to coaxial cable for connection with available coaxial In/Out ports, a pair of screen protectors for 2.4" display, a quick start guide card which has walkthrough of all the ports and buttons in Chinese/English, and a very comprehensive high quality glossy print user's manual. AP100 also comes with a leather case which I'm still waiting to receive due to my shipment being one of the early samples Penonaudio (as official authorized Hidizs distributor) received in their store. I was also told, along with a leather case they're going to include 3.5mm TRRS to TRS adapter since by design AP100 3.5mm headphone port will not be able to accommodate correctly headphones with a built-in inline remote/mic. Typically high quality headphones have either audio only cables or have access to removable audio-only cable. In some cases, like my Beyer T51i where in-line remote doesn't come with a removable cable, you can easily use an adapter. I also noticed, Penonaudio eBay page list AP100 with a bonus free set of hi-fi earphones (http://www.ebay.com/itm/Hidizs-AP10...ortable-HiFi-Audio-Music-Player-/291155982192), though I'm not sure about the model.

Design overview

Once you take AP100 out of ESD bag, you are presented with a very portable and lightweight audio device, approximately 107mm x 65mm x 16mm and weighting 152g (including microSD card). The housing of the player has a solid metal enclosure (no flex) with rounded edges. Upper half of the front side hosts a flush mounted 2.4" TFT color screen with 320x240 resolution. Though not IPS, it actually has pretty wide viewing angle and it wasn't too bad for outdoor viewing. The placement of control buttons in the lower part of the front has a great layout for one-handed operation with either right or left hand. You have a dedicated volume -/+ buttons, a 4-way circle button with next/prev selection placed horizontally and fast fwd/rev placed vertically, where all these buttons are also used as navigation up/down/left/right while scrolling through the menu. In the middle of this circle you have play/pause button which also functions as Enter/Select key, and in the lower right corner a Return button which takes you back to a previous screen and also brings up song playback setting menu when long-pressed during playing music. At the top of the player you have 3.5mm jack for headphone out (HO) and line out (LO) and a power button which also turns the screen on/off while playing music or after screen display time out. On a right side you have a lock button; while enabled this one prevents accidental key presses. On the left side you have SRC button which changes the playback rate by cycling between 16b/44.1k, 24b/88.2k, 24b/96k, 24b/176.4k, and 24b/192k, and EQ button which cycles between General (default flat), Rock, POP, Classic, Jazz, Bass, and User custom EQ setting, and also Reset pinhole. At the bottom you get micro-USB charging/data port, microSD card port (supports max 64GB card), and Coaxial In/Out ports.

Under the hood and User Interface

Inside of AP100, you have 8GB of built-in internal memory (plus up to 64GB through microSD expansion), 3000 mAh li-ion battery which supposed to last 10hr, and array of very impressive chip selection from Cirrus Logic and other top premium IC manufacturers. I find it refreshing how every manufacturer decides to use different building blocks of ICs for their signal chain. Trying to stay unique with sample rate on-a-fly switching, I can see why Hidizs made a decision to use this particular chip set (low jitter phase lock loop, separate clock crystals, asynchronous SRC, etc.) which offers a very clean audio recovery and processing all under a dedicated hardware control. Processing is done using dual core Ingenic 4760B CPU, the same one used on X5.

On top of this hardware, you have a very stable firmware with a clean minimalistic GUI interface. It's not as fancy as scrolling wheel of X5, and doesn't have the same GUI details, but it's functional, easy to get around, and never locked up on me (though I don't have a large library of files to index). Actually, only one time it locked up because I unplugged AP100 from laptop without "ejecting" usb connection - my own fault since it was a part of the provided instructions which I didn't follow. Once you turn the power on, you are presented with 2 choices of going to a playlist or a setup menu. Setup menu has a lot of detailed selections and actually reminds me of X5 in it's look and feel. I tried documenting in pictures all the available options. When it comes to playback menu, it actually resembles a look of HM700 where you have a scrolling list of all the songs according to a file name. The ID3 tags are displayed during individual song playback, otherwise it's just an alphabetical list.

Once you start playing a song, you have a screen with all the detailed info indicating EQ selection, enabled SRC (with a sampling rate displayed on the screen), volume level, battery level, available cover artwork and ID3 tag content, play/pause/ffwd-rev icon indicator, track time line, and full file name (scrolling if its too long). Long pressing Return button takes you to song playback menu with more options. To assist in a better management of your playback, each song can be tagged as "favorite" to be added to a separate directory under "My favorite". Since you have access to up to 72GB of storage space, you probably would want to have a structure of separate sub-directories according to an album or an artist for a better management of content. Those with an excessive audio library probably will be looking elsewhere like X5 where you can use up to 2x 128GB microSD cards and OTG USB storage option. Also, if you want to use your DAP as external USB DAC for your laptop or computer, AP100 will not be able to support this.

Audio quality

As you can see, a lot of thought went into the design, presentation, and selection of components for this new product from Hidizs. But how does it all translates into the most important task, the sound quality? Let me re-assure you, there is NO disappointment in here. The sound is very neutral, detailed, no coloration of excessive low frequency warmth or upper mids/treble harshness or sibilance. The tonality is very natural with sound being accurately represented. Typically I prefer to leave a more detailed sound analysis to when I'm reviewing headphones, but in theory any sound representation comes down to 3 main factors: your sound source file (mp3 or FLAC or other lossless formats), the hardware decoding it (your dedicated audio player or smartphone or combination with an external DAC/amp), and your headphones. When it comes to hardware, in my opinion you want it to be as neutral as possible so you don't add any artifacts to a source, and I think AP100 accomplished that goal. It supports most of the popular audio formats, such as MP3, FLAC, WAV, OGG, WMA, APE up to 24b/192k sampling rate, and it's able to accurately decode these audio formats leaving it up to your headphone sound signature to deliver the final result.

In comparison to X5 (running the latest FW2.0) and HM700, I found AP100 (in 24b/192k setting) to be a little smoother and laid-back, a little warmer, and a bit less bright. Now, keep in mind, this is not a description of the sound, but rather a relative comparison using the same audio file source with the same set of headphones. In direct comparison of AP100 and X5, I found Hidizs soundstage to be a little bit wider and deeper, though not as wide as HM700 with balanced RE400B. Also, switching SRC to 24b/192k which I'm planning to leave on permanently, added more body to AP100 sound and on some headphones improved the sound with a better separation and layering. The results will vary from headphone to headphone, but the most significant change I was able to hear with Beyer T51i where the sound improvement with AP100 was almost like I added an amp to X5.

I do realize that for some a big question going to be if you are on a budget and at a crossroad deciding whether to go with X5 or AP100 or you need to get another DAP. From a form factor, AP100 is a little bit shorter and lighter. From a storage capacity and expansion, X5 is hands down a winner. Perhaps due to a same CPU maybe in a future updates Hidizs will add support for 128GB flash, though you are still limited to a single card and not sure about OTG. Regarding GUI and interface, I think they both have their advantage and disadvantages where I love scrolling wheel of X5 for a quick navigation through a list of songs, but when it comes down to menu selection or more precise song selection - using button navigation will give you more control at expense of slower speed. Also, there is no denial, X5 interface is more polished. Sound quality is where you going to see more distinction. If you need to invest $150-$200 into a portable amp to enhance sound of some of your headphones, perhaps a dedicated DAP might be a better option. The sound quality improvement will vary depending on headphones you use, but I can tell you from a personal experience I will be driving T51i only from AP100, while for my workouts with hifi sound - it's HM700 + RE400B in an armband for convenience. Another great pair up example of AP100 I found to be with ATH-IM50 and IM03. Beside adding more dimension to a sound, it really brings bass alive and makes it stand out especially with IM50 where low end is the strongest point to begin with. So there is no clear answer since it will depend on your individual preferences due to YMMV.

Overall, I must say I was very impressed with this DAP considering I never heard of this company before. Between hardware, firmware, and sound quality - this is one solid release for a newcomer. I especially like how they are trying to differentiate themselves by offering something different with SRC functionality. Please keep in mind, my previous DAP experience is based on Clip+, X5, HM700, and using my Note 2 w/Neutron, so perhaps other higher end DAPs already implement something similar, though I'm not sure if anybody else does it in $300 price range. Also, SRC is not a magic button to improve the sound of every headphone, but it works rather well on those that lean more toward balanced sound signature with enhanced bass response and require a stronger driving signal. Not sure if you will get the same level of improvement pairing it up with analytical headphones since I don't have my Etys and IM02 for testing anymore. Also, all the headphones in my collection are low impedance and Hidizs site doesn't talk much about HO output level driving different impedance loads. But if you look at their spec of 2.2Vrms and assume the lowest supported impedance, it will still scale up to a very decent signal level going up to 250ohm and 300ohm loads and maybe even to 600ohm. While testing with my headphones, I had my volume setting between 1/4 to 1/3 of maximum allowable volume, never approaching 50% of max volume output. That's a good indicator and also goes along with my previous comment of AP100 driving T51i like it was X5+amp. Now, I can't wait to see what future firmware updates going to bring and what other products Hidizs guys have in queue!