To avoid having to use a third power supply for the I/V-converter and analog output filter a negative power supply is derived from the +5 V. Downside of keeping the power supplies separate is two DC adapters are needed. But that would mean degrading the power supply of the DAC. Another option is to use the power supply of the DAC to supply the RPi. We need to make an independent +3.3 V and +5 V. We could use the RPi power supplies available on the GPIO Expansion connector but these are very noisy. Later on we will explain why we increased this supply voltage to +5.2 V (still within recommended operating range!). +3.3 V for the digital part and +5 V for the analog part. The PCM1794A (IC1) requires two different power supply voltages. It is a 24 bit DAC, can handle sample rates up to 200 kHz and has a built-in 8x oversampling filter. We had good experiences with DACs made by Burr Brown and so the choice was easy to use one of their top models, the PCM1794A. ICs from Burr Brown (now Texas Instruments) were and still are among the best. In the past we designed High End DACs for normal use. But since we want to build de audio player ourselves, we designed an audio DAC for the raspberry pi using first class parts. DACs with good quality are already on the market. A good start is to look for applications that use a raspberry pi. If space and mobility is an issue these are not suitable. The one’s with network support have no touch screen or are very expensive. Searching for a small stand-alone networked audio player with a touch screen mostly big consumer amplifiers are found. Using app Volumio it can be used as a stand alone networked Audio Player or operated thru a WebUI. I really like the setup and the possibility to configure things with the Smartphone with the webinterface.This is an Audio DAC designed for the Raspberry Pi. They are all connected to the squeezeserver on the ODROID in the living room that is connected to an AV-Receiver for video (XBMC) and audio (squeezelite) streaming. More details on the Max2Play-Webinterface (pictures and background infos) can be found here: Ĭurrently I use multiple ODROIDs with Max2Play in my living room, bathroom, bedroom and terrace. The Image for the ODROID can be downloaded here: Ī video of how it works (webinterface and smartphone control) can be watched here:
0 Comments
Leave a Reply. |
Details
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |