From reference design to USB sound card

[Entropia] decided to try his hand at rolling is own sound card. He picked out a DAC chip, started his prototyping by studying the reference design from the datasheet, then went through several iterations to arrive at this working model.

He chose to base the board around the PCM2706. It’s a digital to analog converter that has built-in USB … Read the rest

SPDIF passthrough lets you digitally manipulate the audio

[Mike Field] took what he had learned with a few past projects and combined them to make this FPGA-based SPDIF audio pass-through. In order to get the SPDIF signal ready for the FPGA he needed a few components to use for level conversion. Once everything was connected he used a first in first out (FIFO) buffer to ensure that … Read the rest

FPGA generated SPDIF output

[Mike Field] just finished implementing SPDIF generation on an FPGA. SPDIF is an industry standard for transmitting digital audio signals; the acronym stands for Sony/Philips Digital Interconnect Format. It’s been around for more than a decade and since it’s found on most home-audio equipment, building an SPDIF output into your projects may be quite a desirable feature. [Mike] mentions … Read the rest

Digital Audio on the Parallax Propeller

[Beth] had the idea for transmitting digital audio over S/PDIF on a Propeller a few years ago, but only just got around to a writeup. For that, we thank her.

The writeup has a marvelous walkthrough of the S/PDIF protocol and the problems associated with with generating the signal. S/PDIF is a relatively resource-intensive protocol – the signal is … Read the rest

SPDIF switch

switch

When [linux-works] found himself needing a switch that could convert coax to opto, he made one. The main chip is a cd4052 cmos analog switch, which he says is really cheap. The rest is pretty self explanatory.  This setup can switch between 4 different inputs as well as do the coax to opto conversion.… Read the rest