Starting with exterior dimensions, DX220 MAX has been supersized to 145mm x 83mm x 26mm with a weight of about 700g, the reason why iBasso now calls MAX transportable instead of portable. But why increase in size considering it is no longer even a modular design? I will go into more details in the next “under the hood” section of the review, but you have to keep in mind extra room required for 5 battery cells (for separate analog and digital circuits), all dedicated ports, big/tall audio-grade capacitors, custom volume pot, stainless-steel heat-dissipation chassis, and a big 5” 1080p display with 1080×1920 resolution.
The right side of the DAP features no controls (my ‘name’ was etched as part of review unit), while the left side only has a spring-loaded micro SD card slot. While sides are bland and the top/bottom are covered in glass, the visual eye-candy of the MAX design comes through when you examine the front and the back of the chassis. With every individual port having a golden surrounding faceplate, the contrast with stainless-steel chassis makes it look premium. On the front, left to right, you have 4.4mm dedicate Line Out, 4.4mm balanced headphone output, 3.5mm single ended headphone output, and a large golden knob of a custom 4-wiper potentiometer to adjust the headphone output volume.
On the back, you have DC-in for 18V wall charger to juice up analog section batteries. Then, you have a power button with a typical short click screen on/off and long press power on/off functionality. Next to it is USB-C port for charging digital section battery and other digital in/out functionality, and btw, this port also had a cutout with a gold faceplate. And last, but not least, 3.5mm digital SPDIF output which doubles as optical out. For me personally, considering I have been using MAX as my desktop DAP, the location of ports is perfect with power supply cables on the back, and headphone ports and volume control on the front.
I’m sure many will notice something is missing in the design, a traditional hardware transport buttons for play/pause/skip. I honestly don’t know why the decision was made not to include those buttons. Maybe because this is transportable rather than portable device? I don’t want to speculate about the reason, but I do miss this functionality, though you can use many Android media control Bluetooth remotes as a workaround.
Under the hood.
As part of its “DX220” name, MAX still uses a dual SABRE ES9028Pro DAC, the same 8-core CPU and GPU, and 4GB LPDDR3 RAM with a benchmark performance (according to AnTuTu test) being close to the original modular DX220. As already mentioned, you will also find 5” IPS touch screen, Bluetooth 5.0, 5G Wifi, XMOS USB receiver with Thesycon usb audio drivers, and support of QC3.0, PD2.0, & MTK PE Plus quick charge for digital section. The internal storage now is 128GB, and you can expand it with high capacity micro SD card. You still have a support for bit-for-bit playback up to 32bit/384kHz, and native DSD up to 512x, as well as all popular audio formats: APE, FLAC, WAV, WMA, AAC, ALAC, AIFF, OGG, MP3, DFF, DSF and DXD. MQA decoding is supported as well, and so does M3U playlists.
The big change here is in power management where MAX digital and analog sections are partitioned, completely isolated, and powered separately to make sure the noise doesn’t couple from one side to the other. They literally use a separate 4400mAh 3.8V LiPo battery for a digital section of the MAX, and separate 4pcs 900mAh +/-8.4V LiPo battery for analog section of the DAP. That is a reason why you have 2 separate chargers, standard usb-c charger for digital 3.8V battery, and 18V wall charger for analog 8.4V battery. This way you don’t need to use voltage boosters or converters, further isolating digital and analog circuits inside the MAX.
This is especially important for analog Amplifier section of the design, powered by +/- 8.4V battery without loosing efficiency or introducing distortion due to voltage boosters, keeping the power pure. The amplifier section itself is based on AMP8 module with its optimized class A discrete circuit architecture. The headphone output from the amp is very powerful, single ended 3.5mm @4.4Vrms (measured 4.35Vrms with 300ohm load) and balanced 4.4mm @8.8Vrms (measured 8.7Vrms with 300ohm load). With the balanced output alone, this translates into roughly 2.4W of output into 32ohm load and 258mW into 300ohm load. With such high desktop level output power, it comes in handy for MAX to have 3 gain settings. And in addition to independent volume pot controlling analog amp output, you can also use digital volume control to adjust DAC output level like in a pre-amp.
I’m sure many will be curious about battery life considering advanced power architecture and high output power. I ran the battery test on MAX with DAC volume at 135 and Analog volume pot at around 9 o’clock (normal listening), using average impedance and sensitivity IEMs connected to 4.4mm balanced out, med gain, filter 1 setting, BT/WiFi off, screen mostly off, only the occasional glimpse to check the battery status while playing a mix of mp3/flac files in a loop. Under these conditions MAX lasted about 11hrs 45min with digital battery down to 0 and analog battery remaining around 20%. Switching to higher gain, playing higher resolution files, streaming and having BT/WiFi on, and using demanding headphones will add more variables to drain batteries faster.