i’ve finally received the oscillator and then i was able to proceed in my project.
here the final setup of the volumio 1.1Beta installed on a raspy model B.
i’ve build a little breakout/interface board so i was able to connect very efficiently the small dac board on top of the raspberry (so the i2s lines are very short).
plus i’ve built a very little (and stupid) lm317 based linear power supply and injected the +5v directly on the 5v/GND rails on GPIO pins. (todo: add a little fuse for protection as in the original design of raspberry).
is confirmed that this board can work succesfull on volumio 1.1… the only thing i’ve done are :
-> solder the 7x5 smd osc on the board ("L" marking is pin 1)
-> close solder jumper Fb1 that connects regulated 3.3v to the oscillator pin (TODO: use an smd ferrite-bead instead)
-> enable i2s on the web-interface
-> add "snd_soc_hifiberry_dac" and "snd_soc_rpi_dac" under /etc/modules
(fixed on the 1.2beta version)
the oscillator was a 7x5 SMD 3.3v 49.152 mhz but the frequency in async mode is not crucial, you need only to ensure that the freq selected is at least 128fs of the max sampling rate you wanna use on your music material.