basically I want to send my oppomod i2s (dsd) signal to bricasti dac,(which does no has i2s)
I thinking to use wm8804 transeciever and looking at these
https://www.audiophonics.fr/en/inte...erface-i2s-vers-spdif-bnc-wm8804-p-12559.html
and https://store.sure-electronics.com/product/AA-AB41133
however looking at the data sheet said to recieve i2s PCM but does it mean it cannot encode dsd signal into spdif ?
so my alternative solution are i2s striaght into dac interface via the bricasti internal i2s xmod interfaceboard(which the net have no infomration on it yet) or the asynchronous i2s and spdif kit
I thinking to use wm8804 transeciever and looking at these
https://www.audiophonics.fr/en/inte...erface-i2s-vers-spdif-bnc-wm8804-p-12559.html
and https://store.sure-electronics.com/product/AA-AB41133
however looking at the data sheet said to recieve i2s PCM but does it mean it cannot encode dsd signal into spdif ?
so my alternative solution are i2s striaght into dac interface via the bricasti internal i2s xmod interfaceboard(which the net have no infomration on it yet) or the asynchronous i2s and spdif kit
As in the I2S card upgrade from this website?
https://www.oppomod.com/
The description gives me the impression that it has nothing to do with I2S, but that it is a raw DSD signal transported with LVDS interfaces. If so, putting it into an S/PDIF transmitter won't work, as stated on the Oppomod website.
https://www.oppomod.com/
The description gives me the impression that it has nothing to do with I2S, but that it is a raw DSD signal transported with LVDS interfaces. If so, putting it into an S/PDIF transmitter won't work, as stated on the Oppomod website.
Your first alternative may or may not work. You could check with a makeshift low-pass filter and an audio amplifier and loudspeaker if there are raw DSD signals coming out of the interface.
I phrased that rather inaccurately. I get the impression that it outputs I2S when you use it with a PCM signal, but that it switches into raw DSD mode when you use it for DSD. An S/PDIF transmitter can't handle raw DSD. Besides, the levels are probably LVDS, while those S/PDIF interface cards you linked to presumably expect 3.3 V CMOS levels.
If you should want to convert it to S/PDIF, you have to:
1. Use LVDS receivers to convert it to CMOS levels
2. Either decimate it to PCM (which audiophiles normally don't want to do) or add some bits to pack it as DoP (which only works if your DAC supports DoP at its S/PDIF input - in https://www.bricasti.com/en/consumer/m1_specs.php , if that is the right DAC model, I only see that it supports DoP over USB)
3. Put it into an S/PDIF transmitter
You could do steps 1 and 2 with a small FPGA, or with LVDS receiver ICs and a bunch of shift registers and some glue logic if you want to pack it as DoP - but that won't work anyway if your DAC only supports DoP over USB.
When you play DSD over the DAC from its USB input, and you connect 4.7 kohm-2.2 nF low-pass filters to the interface board outputs (one output is probably called SD or DATA or so and the other LRCK or WS or FS) and AC couple those low-pass filters to an audio amplifier using 10 uF (electrolytic) coupling capacitors, do you hear reasonably normal audio coming out of those filters? Don't turn up the volume too high during this test, as that could damage your tweeters.
If you hear reasonably normal audio, the interface format at that point must be raw DSD. You then only need three LVDS receivers and some sort of three-pole double-throw switch or multiplexer to connect your Oppomod signals there.
Edit: I forgot that there may also be MUTE and DSDON signals. You will also have to multiplex those.
Last edited: