Hey Folks,
So - Today Brian and I have been discussing the 4:1/4:2 mux that I have been working on getting designed. I know a few of you have been anxious to get it.
I had it done, and nixed it at the last minute because I didn't like it. I was not comfortable that it was what you people really wanted.
Since Brian and I need to get a good feel for what you folks really want out of the design we are doing the logical thing -asking.
The chip I want to use is a high quality 4:2 bus mux/demux. It will work with TTL and lower signals (like SPDIF).
First - what sort of signals do you plan on MUXing/DEMUXing?
1) PCM/DSD (TTL)
2) SPDIF (TTL or CONSUMER)
Two approaches I am currently thinking of are these (in no particular order):
Approach #1
- Create a 4:2 PCB where inputs and output can be paralleled to create a 4:1
- Allow for stacking so that PCM/DSD (which requires at least 3 signals) can also be used.
- Create a second PCB for SPDIF input - it would possibly include spots for jacks (RCA/BNC or XLR) as well as a trafo for isolation and spots for resistors to setup termination and voltage division as necessary.
Approach #2
If it turns out that most people only wish to use SPDIF - then I would put the trafos and termination parts on the MUX/DEMUX PCb itself and already parallel the channels so that it does 4:1.
We already have the OTTO-II for switching between 2 PCM sources. And most people will not have more than 2. yet it is fairly common to have up to four (or even more) SPDF/AES sources.
So this is your chance to tell us which approach you like better! before I order the boards.
Happy new year!
Cheers!
Russ
So - Today Brian and I have been discussing the 4:1/4:2 mux that I have been working on getting designed. I know a few of you have been anxious to get it.
I had it done, and nixed it at the last minute because I didn't like it. I was not comfortable that it was what you people really wanted.
Since Brian and I need to get a good feel for what you folks really want out of the design we are doing the logical thing -asking.
The chip I want to use is a high quality 4:2 bus mux/demux. It will work with TTL and lower signals (like SPDIF).
First - what sort of signals do you plan on MUXing/DEMUXing?
1) PCM/DSD (TTL)
2) SPDIF (TTL or CONSUMER)
Two approaches I am currently thinking of are these (in no particular order):
Approach #1
- Create a 4:2 PCB where inputs and output can be paralleled to create a 4:1
- Allow for stacking so that PCM/DSD (which requires at least 3 signals) can also be used.
- Create a second PCB for SPDIF input - it would possibly include spots for jacks (RCA/BNC or XLR) as well as a trafo for isolation and spots for resistors to setup termination and voltage division as necessary.
Approach #2
If it turns out that most people only wish to use SPDIF - then I would put the trafos and termination parts on the MUX/DEMUX PCb itself and already parallel the channels so that it does 4:1.
We already have the OTTO-II for switching between 2 PCM sources. And most people will not have more than 2. yet it is fairly common to have up to four (or even more) SPDF/AES sources.
So this is your chance to tell us which approach you like better! before I order the boards.
Happy new year!
Cheers!
Russ
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Well, at least for me (and i think many more) i will use one or two I2S sources, where at least one is PCM/DSD combo, and the other will probably be PCM. And then i will have at least 2 inputs which is SPDIF, one optical and one coax.
So for me Approach #1 will be the best one.
But looking at Approach #2 then i guess it would allow me to have one PCM/DSD input through the normal DSD-input on B3-SE, and put the SPDIF-mux on the SPDIF input port, so i would then have possibility of one I2S and up to four SPDIF, right?
If this secondary alternative is true, then it would work fine for me, but Approach 1 seems more usable for more people.
So for me Approach #1 will be the best one.
But looking at Approach #2 then i guess it would allow me to have one PCM/DSD input through the normal DSD-input on B3-SE, and put the SPDIF-mux on the SPDIF input port, so i would then have possibility of one I2S and up to four SPDIF, right?
If this secondary alternative is true, then it would work fine for me, but Approach 1 seems more usable for more people.
Your setup sounds best served by approach #2 plus an OTTO-II.
You would connect the OTTO-II to the PCM/DSD input pf B3SE and the 4:1 SPDIF mux to the SPDIF input.
Then you would use IP_S to switch between PCM/SPDIF and the OTTO-II and 4:1 mux to switch their sources.
I guess I am not understanding what you want to get from a new product? You already have the 4:1 SPDIF to I2S mux board and now you have the Otto-II 2:1 I2S switch board. so you pretty much have all the bases covered?
I think like you said. most people will have multiple SPDIF sources and one USB type source. Now You may want to combine an the 4:1SPDIF Mux board and the Otto-II boards together into one product creating a 5:1mux where the 5th input is an I2S input for connection to a USB board.
The only instance I can see for a 4:1 or 4:2 I2S switch board is if in some rare instance where someone needed more then 4 SPDIF inputs and wanted to connect 2x 4:1 SPDIF boards and a USB to I2S board. But even then it would only be 3:1
and even rarer yet would be someone that wanted to have 2x I2S output's for switching between 2 different types of DAC chips but I can't imagine you would sell more then a few of such boards. hardly making it worth while.
So am I missing some parameter? Otherwise i think you got it already?
Zc
I think like you said. most people will have multiple SPDIF sources and one USB type source. Now You may want to combine an the 4:1SPDIF Mux board and the Otto-II boards together into one product creating a 5:1mux where the 5th input is an I2S input for connection to a USB board.
The only instance I can see for a 4:1 or 4:2 I2S switch board is if in some rare instance where someone needed more then 4 SPDIF inputs and wanted to connect 2x 4:1 SPDIF boards and a USB to I2S board. But even then it would only be 3:1
and even rarer yet would be someone that wanted to have 2x I2S output's for switching between 2 different types of DAC chips but I can't imagine you would sell more then a few of such boards. hardly making it worth while.
So am I missing some parameter? Otherwise i think you got it already?
Zc
Brian: But it's THAT board we are talking about in combo with the OTTO-II right?
No. THAT board has four inputs and four outputs.
This would be a new board, with on-board isolation (transformers) and 4:1 mux switching (four selectable inputs, one output).
The current 4 channel level shifter for B3 is just that. A level shifter. It does no MUXing. The B3 is the MUX in that case. 4 in 4 out + level shifter.
This new modules is more geared toward the B3SE or even the older B2. 4 in 1 out exactly the same as input. No level shifting involved (as that is done on the DAC).
If you want you could make the new module work for B3 by using the single SPDIF level shifter and then not using the ES9018 MUX but instead using the external MUX.
Cheers!
Russ
This new modules is more geared toward the B3SE or even the older B2. 4 in 1 out exactly the same as input. No level shifting involved (as that is done on the DAC).
If you want you could make the new module work for B3 by using the single SPDIF level shifter and then not using the ES9018 MUX but instead using the external MUX.
Cheers!
Russ
Done. It will use the same methodology as the B3 and the CS8416-based MUX, so that it can be used with the same switch board. For Arduino (or other uC), you need two GPIOs to make a binary selection.
It is possible to use the 2-bit switch selector. You would just wire to the new module instead of to the Buffalo.
I'm not entirely sure that I understand options #1 and #2, so I'll just weigh in with the functionality that would make my life easier. Ideally, I'd like to have a single board that allows for up to four inputs (each of which can be SPDIF/PCM/DSD) and one output. Is that even possible? I would like my DAC to support both coax and Toslink SPDIF as well as two different USB modules (Amanero for now, and the TPA USB module when it becomes available).
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