Starting with exterior dimensions, DX300 has been truly supersized to 162mm x 77mm x 17mm with a weight of about 300g. I referred to MAX as transportable due to its 700g weight and wider/thicker design. It is true that DX300 is taller, but overall size is still slim enough to slide in a pocket of your jeans or to hold it firmly in your hand. Thus, I’m referring to DX300 as a portable DAP, maybe not exactly pocket friendly for everybody, but it does feel more portable than MAX. As a matter of fact, due to its size and a gorgeous 6.5” IPS display (2340×1080 resolution, 19.5:9 aspect ratio, 397ppi) with In-Cell capacitive touch panel, I think iBasso stepped into a new category of Digital Audio Phablets. Btw, my review unit came in obsidian black finish, while they also offer a starry blue finish.
The front of the DAP is flat and occupied solely by a display, featuring a very narrow border where the screen is almost edge to edge. At the top of the display, you have a long indicator bar light (could be turned off in settings) to display color depending on song format and other functionality. The back is aluminum and wraps around left/right sides toward the edges, reminding me a bit of DX160. And while the general shape of DX300 is a rectangular bar with rounded edges, the right side is asymmetric with a sloped edge which enhances the ergonomics of the design for a more comfortable grip to access transport control buttons. All three buttons are the same size, narrow, rectangular, with a nice tactile response and a solid feel. They are not labeled, since the one in the middle will always be Play/Pause, while top/bottom could be flipped and reassigned under Audio Control Button customization setting for either forward/back or the other way around.
Right above the buttons you have a multi-function volume wheel which you can short-press for screen on/off or long-press to power the DAP. The wheel is not flush with the side of the DAP and has a non-slippery edge pattern, making it easy to turn with a thumb while feeling a click action as you turn it to give a more precise control of volume adjustment. I personally find the design and the placement of the wheel to be very convenient since it works great with a case, it is within thumb reach of playback buttons, and due to a large size of the dap you don’t have to move your hand to reach a separate power button to turn the display on after the timeout. Also, keep in mind, iBasso implemented a sensor under the display to enable double-tapping of the screen to turn it on. The left side of the DAP has a spring-loaded slot for microSD card so you can expand the storage with any large capacity flash card.
At the top you have a traditional iBasso setup with 3.5mm Coax output, not optical, electrical only. And usb-c port for charging, data transfer, and digital audio out if you want to connect the external dac/amp. At the bottom is where you host the modular amplifier card, similar to DX200 and DX220 but the card size has changed, providing more room for future expansions. For almost 4 years the module remained the same between DX200, DX150, and DX220. DX300 is a new platform, new bigger design, and it makes sense that module was updated as well. The new default card is AMP11 which has 3.5mm SE and 2.5mm and 4.4mm BAL ports, switchable between phone out and line out. With 3.5mm and 4.4mm having a golden metal plate ring around the port, 2.5mm becomes almost hidden, with some people might even missing it, but if you look closer you will see it between other 2 ports.
Under the hood.
In the heart of the DX300 design, iBasso decided to use four separate Cirrus Logic flagship CS43198 DACs, arranged in a quad DAC chips array. These 4 DACs now form a total of eight DAC channels, with DAC chips double-paralleled to achieve fully balanced output. On top of that, iBasso implemented Qualcomm Snapdragon 660 SoC 8-core processor, a HUGE step up in comparison to their previous platform. Along with 128GB ROM and 6GB LPDDR4x RAM and with optimized Android 9.0, DX300 benchmark results are very high, matching AnTuTu 3D Benchmark score of other top performing 660/Android 9.0 DAPs (R8 and R6 2020). Keep in mind, DX300 still carries the legacy of dual OS boot, and in addition to Android 9.0 it also supports 5th Gen Linux-based Mango OS. When it comes to playback, it supports most of the lossy and lossless formats up to 32bit/384kHz and DSD256, including APE, FLAC, WAV, WMA, AAC, ALAC, AIFF, OGG, MP3, DFF, DSF, DXD, and MQA (decoding in hardware).
Another addition to the design is in-house developed FPGA-Master. Of course, iBasso is not manufacturing their own FPGAs, but they did implement FPGA and developed FPGA-Master code to make it function as audio system controller to offload SoC processing by directly requesting audio data, as well as syncing and generating all audio clocks to reduce the jitter. DX300 is a multimedia powerhouse and managing resources between System and Audio Processing is important task in order to maximize sound performance. Furthermore, DX300 USB-C port supports USB 3.1 standard, and Wireless is covered by Bluetooth 5.0 with all the popular codecs and WiFi 802.11b/g/n/ac. Wifi also stepped it up with a dual band 2.4GHz and 5GHz and two antennas (2x2MIMO) to establish up to two streams of data with the receiving device. According to iBasso, with two spatial streams established, the data payload is divided across both antennas and transmitted over the same frequency band. And results speak for themselves, WiFi signal is strong and download/upload speed is on par and even better than on my Smartphone.
Adapted from MAX design, DX300 now features iBasso own patented dual battery power supply architecture. You will find 3.8V 4000mAh Li-Po for Digital application and 3.8V 2000mAh Li-Po for Analog application, mostly for AMP card. But unlike MAX where you need to use 2 separate chargers, here you only need one USB-C and can use either QC3.0 or PD2.0 quick chargers, or any other charger, though it will charger slower. In my testing using 4.4mm BAL output w/IEMs, middle Gain, Wifi on and streaming Amazon Music HD, while periodically turning the display on with 5min timeout setting to get more screen time, I was getting approximately 13.5-14hrs of playback time when analog side went down to 0% and digital was down to about 5%.
The last, but not least under the hood is a default AMP11 card, which is based on AMP8 discrete circuit design and secured in place with 2x T3 screws. The analog battery of DX300 provides +/-8V power supply to this amplifier card which has a max output current of 2.7A, providing both high current and high voltage of 7.1Vrms. As I was finishing up this review, iBasso announced AMP11 MKII, a minor update due to a component shortage (discontinued transistor), forcing them to slightly modify the AMP11, still with the same sound characteristics and overall performance (according to iBasso), except max current output is down to 2A now. The phone output of this card is very impressive, 4.4mm/2.5mm BAL out is 7.1Vrms, with a power of 1240mW @32ohm, SNR 125dB, and output impedance of 0.39ohm. For 3.5mm SE phone out you get 3.5Vrms, 350mW @32ohm, SNR 123dB, and 0.43ohm OI. The same output voltage is valid when you switch to Line Out, but if using BAL Line Out with external amplifiers, 7.1Vrms might be too much to handle for some, so a good idea to switch to Low Gain under LO to reduce output voltage.