Is it possible to extract 'data' line from I2S stream from digital source and feed it with GND reference directly to TOSLINK input of another device in the same enclosure omitting its optical input interface? Power supply grounds of both devices are common. I2S measures 2.8-3.3V on high state, depending on supply voltage. Cable length is few cm. Two wires. Receiver reclocks input data with its own internal clock.
You have a SPDIF output and a TOSLINK input physically close to each other and you would like to connect the SPDIF output directly to where the output of the TOSLINK input goes, thereby bypassing the TOSLINK interface altogether?
If so, you could probably remove the TOSLINK connector or cut the trace to its output pin, and connect the SPDIF signal into that point using a small capacitor. If something like that sounds like what you want to do, there are some schematics of basic TOSLINK and SPDIF interface circuits in the SRC4392 data sheet. You can get an idea for how the electrical connections work from that. SPDIF often uses a small pulse transformer for isolation which is optional, but may be considered if any ground related problems were to be discovered.
If so, you could probably remove the TOSLINK connector or cut the trace to its output pin, and connect the SPDIF signal into that point using a small capacitor. If something like that sounds like what you want to do, there are some schematics of basic TOSLINK and SPDIF interface circuits in the SRC4392 data sheet. You can get an idea for how the electrical connections work from that. SPDIF often uses a small pulse transformer for isolation which is optional, but may be considered if any ground related problems were to be discovered.
I would say no to this as s/pdif (toslink) is a biphase NRZ coded. I dont think that the the data line on I2S has that coding.
So which is the cheapest I2S -> s/pdif converter board (I2S master!!) ?
Sorry for the semi hijack
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Ground is never decoupled. You must mean VCC or something like that that is decoupled?
If so, it is a DC power noise filter.
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Hi Guys.
I hope that WindForce85 (pozdrawiam) won't mind of me merging in to his topic, but it's somewhat relevant / related question i think.
I'm running an Alpine RUX-H701 DSP in my car audio system. The output is 7.1 RCA and I'm thinking of eliminating the RCAs alltogether and extending the digital path even further (outside the DSP unit), thus shortening the analog path of the signal.
The internal 8ch DAC of the RUX is PCM1608 that has I2S input in the form of four independent DATA lines and associated BCK and LRCK.
I am thinking of hijacking these signals and feeding them in to I2S-to-TosLink converters (one per data line) and sending the signal to the receivers quipped with some decent DAC that will be built into the amps themself (3x JL Audio 300/2v2 and 1x SS15k) that drives my speakers...
I guess it is wort of mentioning that in my current setup I have no issues, considering that the RCA cables are no more than 1.2m in the longest scenario (subs...) and the full range RCAs are no more than 0.9m in length
RCA cable is rather prime quality with loads of shielding
I don't have any real needs to convert the Alpine into the above... However I'm quite tempted to do so.
What pushes me towards that idea is updating the DAC itself with something more modern and with better DR/SNR/THD+N/IMD and dividing it to four of two-channel independent ones
Financially it may not make much of a sense as it would be not far from £300, but I'm still quite keen.
What I don't know is whether the internal DSP processor of the RUX needs to see the 8x zero detect signals and whether ML/MC and MDI/O signals are needed for the unit to function properly ?
Another thing is that I think that the output volume control is done in analog fashion at the very ond of the analog signal path by means of two TC9482NG...
This on its own puts me kinda off this project because I'm unsure how then would I control the output volume (other than digitally at the source - iPad mini and Bluetooth 5.0 AptXHD + TosLink into the RUX input)
So wrapping up, my question is whether "borrowing" data and clock signals from the existing DAC input while leaving the DAC in place would work at all ?
Any input / suggestions / bullying will be highly appreciated
I hope that WindForce85 (pozdrawiam) won't mind of me merging in to his topic, but it's somewhat relevant / related question i think.
I'm running an Alpine RUX-H701 DSP in my car audio system. The output is 7.1 RCA and I'm thinking of eliminating the RCAs alltogether and extending the digital path even further (outside the DSP unit), thus shortening the analog path of the signal.
The internal 8ch DAC of the RUX is PCM1608 that has I2S input in the form of four independent DATA lines and associated BCK and LRCK.
I am thinking of hijacking these signals and feeding them in to I2S-to-TosLink converters (one per data line) and sending the signal to the receivers quipped with some decent DAC that will be built into the amps themself (3x JL Audio 300/2v2 and 1x SS15k
) that drives my speakers...I guess it is wort of mentioning that in my current setup I have no issues, considering that the RCA cables are no more than 1.2m in the longest scenario (subs...) and the full range RCAs are no more than 0.9m in length
RCA cable is rather prime quality with loads of shielding
I don't have any real needs to convert the Alpine into the above... However I'm quite tempted to do so.
What pushes me towards that idea is updating the DAC itself with something more modern and with better DR/SNR/THD+N/IMD and dividing it to four of two-channel independent ones
Financially it may not make much of a sense as it would be not far from £300, but I'm still quite keen.
What I don't know is whether the internal DSP processor of the RUX needs to see the 8x zero detect signals and whether ML/MC and MDI/O signals are needed for the unit to function properly ?
Another thing is that I think that the output volume control is done in analog fashion at the very ond of the analog signal path by means of two TC9482NG...
This on its own puts me kinda off this project because I'm unsure how then would I control the output volume (other than digitally at the source - iPad mini and Bluetooth 5.0 AptXHD + TosLink into the RUX input)
So wrapping up, my question is whether "borrowing" data and clock signals from the existing DAC input while leaving the DAC in place would work at all ?
Any input / suggestions / bullying will be highly appreciated
No point in that. TOSLINK is very jittery. If you wanted to send I2S over TOSLINK best to convert it to optical SPDIF, since clock recovery would be needed on the receiving end anyway. If you used Sabre dacs, say, ES9038Q2M, then you could use the internal digital volume control feature. Much better to control volume that way rather than at the source since you would lose bit resolution if digitally attenuated at the source end.
Also, while it could be done, and while sound quality could be made much better, if you want good sound quality it can be a lot of work. You might be able to use low cost Sabre dac boards and get pretty good sound. There is one that goes for around $99 and at least measures quite well for the price. Don't know how easy it would be to hack into the electronic volume control though, would have to look into it. Maybe someone else knows.
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