Cayin N6ii Digital Audio Player with Android OS and Exchangeable Motherboard N6ii (aka N6 MK2) is the latest Android based DAP from Cayin. This is their first modular based portable player, and they have adopted a very innovative approach to their modular concept. Cayin’s Audio Motherboard consists of DAC and analogue amplification circuit, so when you change the module, you basically change the complete audio circuit completely, that's why they called it Audio Motherboard. N6ii is powered by a Snapdragon 425 SoC paired with 4GB DDR3 RAM. It runs on a customized Android 8.1 with Google Play pre-installed and Direct Transport Audio (DTA) bypassing Sample Rate Conversion (SRC) of Android system completely, all music playback (local and streaming) from all applications will decode in original Hi-Res without resampling. N6ii comes with Cayin Music and HiBy Music pre-installed as well as HiBy Link. Via HiBy Link app on your mobile you can adjust volume, remote control playback, manage and search music library and create playlists from HiBy Music App. The N6ii features a large 4.2″ 768×1280 HD IPs display with 64GB of internal storage, plus a microSD card slot that accepts any micro SDXC format TF card (verified up to 512GB) with almost unlimited OTG storage capacity. It's powered by a huge 5900mAh rechargeable battery, supporting quick charge 3.0 that charges the N6ii from 10% to 90% in 110 minutes. N6ii is equipped with I²S digital output (or Inter-IC Sound) via a HDMI Type-C connector (aka. Mini-HDMI). This is definitely the most preferred digital interface both in terms of digital capability and audio performance. If you are using a Cayin DAC with compatible I²S input, such as the CS-100DAC or iDAC-6MK2, this will be the preferred digital interface. N6ii comes with dual band 2.4G/5G WiFi connection that supports OTA firmware upgrade, online streaming (install apps via Google Play or APK) and NAS playback (using 3rd party DLNA app) as well as Bluetooth 4.2 supporting multiple Bluetooth codecs like SBC, AAC, aptX and LDAC *. Facilitates up to 96kHz Hi-Res wireless audio. * Bluetooth: SBC and LDAC (Receiver mode) will be added through subsequent firmware update The A01 Audio Motherboard The A01 Motherboard is designed around the AKM flagship AK4497EQ DAC chipset. To make sure the premium DAC chipsets will operate in optimum condition, they have employed THREE extremely low-noise high-precision Femtosecond Crystal Oscillators (45.1584MHz, 49.152MHz, 100MHz). High precision low jitter digital transmission is the base of high-quality digital playback. It is how they deliver a natural, non-digital and musical playback to subsequent audio circuit. It is fully optimized for fully differential amplification, and the final headphone output stage employs 4 pieced of OPA1622 in parallel amplification configuration. This will increase the output current capability and lower the output impedance. In practical, these improvements will translate into better control, ability to sustain a heavier loading, and drive most portable headphones with ease and offers lots of headroom. This is Cayin’s first modular-based portable player, and the Audio Motherboard consists of DAC and analogue amplification circuit and it comes with 3.5mm phone out, 3.5mm line out (dedicated), 4.4mm phone out and line out (shared). The following video illustrates the installation process of Audio Motherboard.