USB audio DAC with PCM2704


I need for my high quality DAC convertor from USB to S/PDIF. I choose PCM2704 circuit, which sent me TI company like sample. Circuit has analog output for headphones and digital S/PDIF output with electrical and optical(TOSLINK) interface. We can use too 3 HID buttons for setting volume and mute.

Circuit description

Schematics is almost identical to PCM2704 datasheet. Circuit includes these components: DAC, S/PDIF output and HID part with three buttons MUTE, VOL+ and VOL-. For USB input is used standard miniUSB connector. Headphone output uses standard 3.5″ stereo jack socket. For signal conversion from TTL level to differential signal is used RS-485 bus transceiver. For optical output is used optical transmitter TOTX173 from Toshiba.

Source: pavouk




  1. steff40 June 23, 2010 8:10 pm 

    Hi there

    I find your USB DAC with PCM2704 very well.
    Can i buy it anywhere or is it only a unicate from yourself? I need another

    for my own Hifi. Can you help me about this? Please answer me :

  2. TehnikService June 23, 2010 10:49 pm 

    You can try on ebay or search on google see this link.

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