Introduction

Hidizs is an audio brand that's been around since 2009, which makes it one of the more established companies in the rapidly growing world of portable/pocket HiFi. Indeed, the founder proudly talks about fronting a rock band while in college and wanting to making on-the-go audio more accessible and affordable to everyone. This comes in the form of Hidizs developing and selling portable DAC/amps, dongles, DAPs, and even IEMs. Indeed, we took a look at the impressive Hidizs S9 Pro as part of this review and ideally I'd have had time to cover one each of the brand's IEMs and DAPs by now. But then the company representative reached out to me about a new venture in the making, and here we are today taking a look at the all new Hidizs XO portable DAC/amp, courtesy a review unit kindly sent to TechPowerUp!


If the title wasn't enough to get you to read further, then surely this title photo will! In an unexpected twist, Hidizs has managed to do to headphone DAC/amps what we've seen happen in the PC DIY space for a while now. The new XO portable DAC/amp has RGB LEDs that are there purely for aesthetics, and you can even select between static and dynamic lighting effects—I can already hear the comments being typed about this. What we can also tell is the Hidizs XO comes in three color options and offers both single-ended and balanced outputs, in addition to MQA support for those who care. We'll cover the XO in more detail today in this quick look article that begins with a look at the product specifications below, so be sure to click the image twice to fully open it and go through all the details.

Packaging and Accessories

Hidizs has already finished the retail packaging for the unit, and perhaps now is a good time to mention the Hidizs XO was originally slated to go on Kickstarter before the company changed its mind given how finished a product this already is at this stage. As such, it will be up on sale on the Hidizs website and its retail partners right away without any waiting period. Going back to the packaging, we see the use of a square-shaped box with a black base that has the company logo and product name on the front in addition to a render of the DAC/amp all lit up from the sides. On the back are more marketing features and some product specifications, which slightly differ from what's on the product page; perhaps this is a case of the product box being slightly out of date. I then noted my username on the side indicating this sample was made for me, and it's a sticker placed on a premium-feeling hard shell box that has the Hidizs logo and slogan on the top.


Another sticker on the side confirms the exact model and SKU inside, while also confirming a 2-piece design with the lid lifting up to reveal the Hidizs XO placed inside a plastic wrap and surrounded by foam, for protection on its way to you. I appreciated the tags used to help remove the DAC/amp as well as to gain access to the accessories seen underneath. There's paperwork in the form of a QC card, a note containing the unit's serial number, and another note which is simply a reminder to register for the company's VIP program to get news, updates, and a 5% discount code in your email inbox. There is no product manual available at this time, although the product page does a good job walking you through the features on board. Hidizs also includes a short and low-profile USB Type-C to Type-C cable here in addition to a Type-C to Type-A adapter, albeit one that doesn't match the cable well in design, to allow easy connectivity for this wired-only portable DAC/amp with Android phones and PCs/laptops. There is no Lightning cable provided, so you will need to supply your own OTG cable if you are on the iOS side of things.

Closer Look and User Experience

At 55 x 24.5 x 9 mm, the Hidizs XO is on the smaller side of average for portable DAC/amps and holds up the company's tradition of making pocket-friendly audio gear. Indeed, it also weighs a meager 11 g, to where there are some IEMs that are heavier! This comes courtesy the use of CNC-machined aluminium alloy for the chassis to keep things light yet sturdy. I never once felt the Hidizs XO came off as cheap, to give you an idea. The aluminium alloy gets a beaded finish with delicate chamfers for a good balance of function and form—no fingerprints or dust sticking here! It comes in three colors of white, black, and this rose gold version I have here. On the front is Hidizs spelled out and then come the two buttons that make this the XO—get it? These are the only two buttons or modes of interaction on the device, and have a nice tactile feedback to them.


On the back we see my username laser engraved which won't be the case for the retail units of course. What you will get is all that branding to the left which I could personally do without, but at least it will all be concealed in use. The longer sides have uniform cutouts in the aluminium alloy that are shaped like an H (for Hidizs) as seen vertically, and these are cutout for a very specific purpose we will get to soon. The shorter sides have the I/O in the form of the expected Type-C port on the bottom and the headphone outputs at the top. Hidizs has gone with a 3.5 mm single-ended output along with a 2.5 mm balanced connection. I do wish it was a 4.4 mm output instead of the 2.5 mm version that's quickly going out of fashion, but most IEM modular cables do still accommodate it for now.


There is only wired connectivity on offer here and using the Hidizs XO with my Android phone is as simple as plugging in the provided USB Type-C to Type-C cable on both ends. The device is automatically detected as an audio output and we now see there is an LED ring around the "O" button that lights up green as a visual indicator of the power and data signal being provided. This is a static light that also indicates the playback sampling rate, with green being the color chosen for PCM 44.1/48/88.2/96 kHz playback. It will change to yellow or red for higher PCM rates, magenta for MQA, and blue for DSD playback. Likewise, pressing the O button will toggle between two preset filters that will be indicated by a brief use of blue or red colors before going back to the static light indicating the sampling rate itself. The filters don't do much in the human hearing frequency range, as typical of such things, but I suppose you can try for yourself.


Now we get to the X part of the Hidizs XO and this button is dedicated solely to side lighting! Indeed, the Hidizs XO has the side LEDs off by default and pressing the X button toggles through 15+ static and dynamic lighting effects, some of which are seen above. The goal here is to make for an attention-grabbing portable DAC/amp on your desk but ultimately it's a gimmick, and one that ends up consuming more power from the client device. I admire what Hidizs has done here and it obviously gets attention from the public too, it's just not something for the audiophile purist who (a) probably couldn't care less about RGB and (b) is further concerned about an LED power delivery and control section alongside the audio one.


Speaking of the audio hardware, Hidizs has gone with the recently released ESS Sabre ES9219C mobile digital-to-analog chipset in a dual DAC configuration, and the circuit diagram confirms the side lighting uses 10 RGB LEDs that are separated from the audio section. The Hidizs XO doesn't have a standalone amplifier section outside of what's provided with the DACs, but does use independent crystal oscillators for output channel frequency matching. The hardware comes together to make for more than satisfactory specs of THD+N as low as 0.0005%, SNR of 119 dB, and crosstalk of 118 dB off the balanced output, with the numbers faring slightly worse but beyond practical discernibility for the single-ended output. You get up to 78 mW per channel @32 Ω off the 3.5 mm connection and 195 mW per channel @32 Ω from the 2.5 mm output, to where its not the most powerful portable DAC/amp in the world but still plenty enough to drive anything you are really willing to take along with the Hidizs XO. As far as playback goes, there's PCM 32-bit 384 KHz and DSD256 on offer in addition to MQA 16x on-device rendering. That's really where the Hidizs XO differentiates itself from the S9 Pro we saw before which is, in my opinion, a better pure audiophile source as long as you don't care about the LEDs and the MQA support. Indeed, the lack of volume and/or gain controls on the Hidizs XO can be potential dealbreakers for some, although the S9 Pro is no different in this matter.


The good thing is you get something that is arguably way better in the form of native support with HiBy's excellent HiByMusic mobile app. I've covered the functionality and customization possible with this music player/content curation/EQ/plug-in powerhouse of a mobile app before and you just have to go to the settings tab to allow for USB device control and hardware volume control to now get 32 steps of volume control for the headphone outputs on the Hidizs XO, that is separate from the client device's volume itself which is best set to 100%. The extensive EQ settings also come in very handy here and you can save any number of EQ presets on the phone itself for different IEMs/headphones connected to the Hidizs XO. Do try out the MSEB and the optional plug-ins too, they work in interesting ways with HRTF considerations in mind, and are certainly more appreciable than the onboard filters. In my opinion, this mobile app is what really makes the Hidizs XO a worthwhile portable DAC/amp compared to most others on the market.


I mentioned before how the Hidizs XO has enough power off even the 3.5 mm output for most consumer IEMs/headphones and it does a good job doing so without getting overly warm either, given it's otherwise cool to the touch. As with just about any other ESS Sabre DAC implementation, the sound signature provided is clean and precise. There's a dark enough background when nothing is playing allowing for better contrast and dynamism off the transducers themselves. Some naturally brighter sets might sound even brighter—it's quite subtle but was reproducible enough to merit a mention—but otherwise it's just a case of non-colored sound being sent from your PC/mobile phone as really all that can be expected from a portable DAC/amp in the $100 price range. The mobile app support of course allows you to tinker further to your desire as seen above. I am not going to claim this enhances the sound meaningfully or expands the soundstage etc, I never felt it does anything of the sort and I didn't detect any effect of having the RGB lights on or off on the sound signature either. By now I hope you have a better idea of what to expect from the Hidizs XO, including its strengths and weaknesses. It's an interesting set that aims to differentiate itself and appeal to the more RGB-friendly crowd. If you happen to be among them then you can find the Hidizs XO on sale for $89 at launch on the Hidizs website as part of a launch promotion from Dec 15-21, following which it will sell for its MSRP of $99 from Hidizs directly as well as its various retail partners.