The AI-503 is an integrated amp and USB DAC that supports inputs up to 11.2MHz DSD and 384kHz/32-bit PCM. The DAC/preamp which is the heart of the unit follows the same design concept of our UD-503 and adopts a dual-mono circuit design that is fully balanced. Separate VERITA AK4490 D/A converters - made by Asahi Kasei Microdevices Corporation - are used for the left and right channels. In addition to a USB digital input (for Windows/Mac computers) optical/coaxial digital input and RCA analog input we have also enabled high-resolution wireless audio listening by including a LDAC-compatible Bluetooth® receiver. Furthermore with a combined 3.5mm optical digital/stereo mini jack on the front panel the unit supports wired as well as wireless input from DAPs. The power amplifier uses a Class-D power amplifier (made by ICEpower a/s) that guarantees high resolution during the playback of delicate signals as well as high linearity at high volumes. This unit can power both compact bookshelf speakers (for desktop applications) and large floorstanding speakers.