I'm looking to feed I2S from HDMI audio or specifically the ARC port of newer televisions to a Twisted Pear B3pro. After looking around a while I realized there's nothing out there (that I could find) diy wise that could do it. So I knew there were plenty of audio extractor boxes, most of them were toslink. If I was going to compromise I would use coax spdif out from one of these boxes. I had one of these from Amazon basics that cost $20 and it did the job well feeding my receiver for a few years. I decided to take the cover off and see what was inside
I looked up the chip inside and found out that it is made by this company
https://www.semiconn.com/ep92a3e
The cool thing is that is has I2S output but I could not locate a data sheet to see what and where those pins might be. I've sent an email to that company to see if they'll send me one. If someone knows where to find it please post it.
What's even better is this set of pads labeled JR1 has the right amount of pads for I2S. Could this be I2S? The unit in question is here
https://www.amazon.com/AmazonBasics...jbGlja1JlZGlyZWN0JmRvTm90TG9nQ2xpY2s9dHJ1ZQ==
I don't have the knowledge or tools to try and figure out what JR1 is. Does anyone have a schematic of this unit? I would think it's mass produced under several makers and models.
Any thoughts? Help?
I looked up the chip inside and found out that it is made by this company
https://www.semiconn.com/ep92a3e
The cool thing is that is has I2S output but I could not locate a data sheet to see what and where those pins might be. I've sent an email to that company to see if they'll send me one. If someone knows where to find it please post it.
What's even better is this set of pads labeled JR1 has the right amount of pads for I2S. Could this be I2S? The unit in question is here
https://www.amazon.com/AmazonBasics...jbGlja1JlZGlyZWN0JmRvTm90TG9nQ2xpY2s9dHJ1ZQ==
I don't have the knowledge or tools to try and figure out what JR1 is. Does anyone have a schematic of this unit? I would think it's mass produced under several makers and models.
Any thoughts? Help?
I doubt its an I2S output for a number of reasons :
- The I2S output capability of the chip is 8 channels (4 pairs) which would require more pins than 5
- A typical I2S output would be 4 signal pins plus GND, here there only look to be 3 signal pins
- R49 and R50 look to be pull-ups, I2S has no reason to need pull-ups
It certainly is worth looking at. I'd be happy to send one to someone who could look at it with a logic analyzer. I have no problem buying a cheap one and learning how to use it but I'm not sure someone could do it quicker and far better than me. Let me know, I'll ship one to someone in the US.
On a side note these chips are available on aliexpress. I have no problem getting a few if someone could layout a board. Soldering that package is another feat in itself, again I'm willing to try. Nothing ventured, nothing gained. My needs are only I2S out for 2 channel stereo and spdif.
On a side note these chips are available on aliexpress. I have no problem getting a few if someone could layout a board. Soldering that package is another feat in itself, again I'm willing to try. Nothing ventured, nothing gained. My needs are only I2S out for 2 channel stereo and spdif.
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I Found this...
https://www.aliexpress.com/item/225...c3!67365152884!sea&curPageLogUid=7jDVsa3LModU
Looks to be the same chip with all the outputs available
https://www.aliexpress.com/item/225...c3!67365152884!sea&curPageLogUid=7jDVsa3LModU
Looks to be the same chip with all the outputs available
It depends on the chips used. I mentioned it as one of the possibilities for transporting multichannel digital data, apart of using multiple 2ch lines. E.g. many ARM chips offer TDM PCM interface. Even the PCM interface of RPi offers TDM mode, but only 2 slots of the 8 can be filled with data (HW limitation).
My comment was related to:
saying that instead of multiple 2ch data lines a single TDM line could be available. Not related to any specific chip.
I'm not familiar with that one specifically but after some research I found out that the chip in there does output i2s but when they're on a board like that it's hard to tell if the output pins are exposed. I found one on ebay that used the shame chip and had all the I2s output pins exposed. The aliexpress link posted above does still work. Try ordering that one and see.
I have it but won't be able to start playing with it until my house is finished and my workshop started. At least 2 months unfortunately. But when I'm up and running this is probably the first thing I'm going to play with
I have it but won't be able to start playing with it until my house is finished and my workshop started. At least 2 months unfortunately. But when I'm up and running this is probably the first thing I'm going to play with
One of our electronics specialists gave me valuable tips on the topology of these chips. He indicated that there is a DAC on which the I2S signal is given. In my case, it is CS4344
https://www.farnell.com/datasheets/88361.pdf
Everything seems to indicate that this is also the case in your case, marked with a red box
Attachments
If you buy this the I2S is on and HDMI connector and on an exposed 6-pin connector. PS Audio format.
https://www.audiophonics.fr/en/hdmi...l-to-i2s-coaxial-optical-4k-60hz-p-13419.html
I just bought one for use with an Oppo BDP-103 and an Analog Precision Ultimate Pre-Amp.
Still playing with it to get native bitstream data. DVD-A's give 94/24 via HDMI and coax.
SACD's give 88.2kHz using LPCM. I have to make sure that I am using the right HDMI connector on the Oppo. The manual says that bitstream is only available on HDMI OUT1.
So far it's the best solution I have found. I have a bare board version of this but it didn't work. I have tried a couple of HDMI extractors and they haven't worked either (starting a collection).
This is the best so far and I use the HDMI connector for the I2S.
https://www.audiophonics.fr/en/hdmi...l-to-i2s-coaxial-optical-4k-60hz-p-13419.html
I just bought one for use with an Oppo BDP-103 and an Analog Precision Ultimate Pre-Amp.
Still playing with it to get native bitstream data. DVD-A's give 94/24 via HDMI and coax.
SACD's give 88.2kHz using LPCM. I have to make sure that I am using the right HDMI connector on the Oppo. The manual says that bitstream is only available on HDMI OUT1.
So far it's the best solution I have found. I have a bare board version of this but it didn't work. I have tried a couple of HDMI extractors and they haven't worked either (starting a collection).
This is the best so far and I use the HDMI connector for the I2S.
Interesting that the HDMI pairs appear to be going in to the part of the chip normally attributed to the MCU. Am I reading that wrong?
I tend to agree with abraxalito. JR1 doesn't appear to have enough pins. The middle pin seems to be labelled 3.3V unless that's an indicator for some other test point.
I only expect to use my extractor for stereo.
I tend to agree with abraxalito. JR1 doesn't appear to have enough pins. The middle pin seems to be labelled 3.3V unless that's an indicator for some other test point.
I only expect to use my extractor for stereo.