The web server, audio file player and DAC base on a 24-bit Burr-Brown PCM1794 chip. Inside there is an integrated computer with an SSD disc, connected to a D/A converter board through USB.
PCM 2704 (sampling frequency 32kHz; 44,1Khz and 48kHz) is used as a USB DAC. It decodes the digital signal from the computer into an S/PDF signal, which is then fed into WOLFSON MICROELECTRONICS WM8804 S/PDIF receiver/sender.
WM8804 accepts 16 and 24-bit signals and frequencies between 32 and 192 ks/s.
SRC4192 upsampler converts a 16-bit signal into 24 bits.
The analogue output is built on 6N23P vacuum tubes in SRPP circuit.
Each module: computer, DAC digital section and DAC line section has independent power supply. Management of the computer is performed in open Volumio software on any device with a web browser, i.e. smartphone, tablet, laptop…