USB Digital Audio Converter miniaturized. It reproduces any digital music content, by the MP3 wire to high-resolution formats. Compatible with Apple and Windows platforms and with iOS and Android devices. Asynchronous data transfer USB Class 1 using the protocol Stremlenght TM. Output at constant level for connection to preamplifiers or sintoampli. The high output level (2.1V) is sufficient to drive virtually all headphones on the market. Using the 32-bit DAC ESS 9016 with a reduced phase shift filtering. digital volume control Bit-perfect.