The new HD-BT II-D Bluetooth Module is more than an accessory. It allows you to interact with the amplifier via your mobile phone for music streaming (with aptX HD quality) and use the APPs (with ST-X DSP III Series) to do everything necessary for a complete setup and tune of the DSP.
 
Specifications
 
120 MHz Qualcomm Audio DSP
32 MHz Dual Core Processor
High-Performance 24-bit Stereo Audio Interface
aptX, aptX HD Adaptive
SBC and AAC Audio Codec Support
Digital Outputs
Compatibility: HDSP-V, ADSP-IV, ST-X DSP III