If we can't find a way to use it then I agree.....otherwise if there is someway to use it and noones told us yet?
Not particularly 😀 Just noone seems to know how to make a module that would take DSD from say a DVD player that supports it and feed it into the DAC. Was thinking of a module to use that would accept firewire or HDMI as I believe thats the only way to use DSD with SACD and what not.
Russ,
I will put together a sorta mini app note on how to wire the chip up such that you only need 3 pins connect and you can get all channel to parallel together in all 3 modes. I know I should have just made it easy programming but that would be no fun right? No just kidding, I really overlooked that and its my mistake. But for now, you can short
DSD5 to DSD1
DSD6 to DSD4 to DSD2.
With these pins connected like so, there is 2 register setting you can make to get stereo mode for SPDIF/SERIAL/DSD input.
Also, pin25 on your schematic should be connected to 3.3V
I will get you the register settings soon.
Thanks
Dustin
I will put together a sorta mini app note on how to wire the chip up such that you only need 3 pins connect and you can get all channel to parallel together in all 3 modes. I know I should have just made it easy programming but that would be no fun right? No just kidding, I really overlooked that and its my mistake. But for now, you can short
DSD5 to DSD1
DSD6 to DSD4 to DSD2.
With these pins connected like so, there is 2 register setting you can make to get stereo mode for SPDIF/SERIAL/DSD input.
Also, pin25 on your schematic should be connected to 3.3V
I will get you the register settings soon.
Thanks
Dustin
dusfor99 said:
Thanks Dustin,
That will be great, but I was also hoping to support use of the PCB without a microntroller (at least for I2S mode). Would this still work?
Thanks again!
Russ
If you just want I2S and nothing else, then just simply wire the RSD0/RSD1/RSD2/RSD3 all toggether and powerup.
Thanks
Dustin
Thanks
Dustin
dusfor99 said:
Right, I understood that, but what I meant was I want to be able to support both operation with a uC and without.
What I am thinking now is that I will likely just go ahead and add a uC to the board.
Cheers!
Russ
Dougie085 said:
For the DIY'er you can do this. (Its what I did to 10 units)
1. buy a Denon 1940CI DVD player
2. open it up, find the DAC is a BB DSD17xx or something, find its datasheet.
3. Build a header onto the back of the denon unit.
4. tap the DSD and I2S signals to the header.
5. close it up, and conenct to the Sabre DAC.
Make sure you do a before and after FFT you will be happy.
Dustin
DSD3 gets tied to DSD1 inside the chip. You see, I had some foresight, just not enough of it 😉 DAC's 3,4,7,8 can be connected internally to DAC's 1,2,5,6 respectively. I had to come up with this cluge in order to make it so that a customer could hardwire the PCB and still be able to support all data formats in 2 channel configuration.
Kinda sucks having the chip out exposing all the shortcomings, but I guess that to be expected on the first one.
Dustin
Kinda sucks having the chip out exposing all the shortcomings, but I guess that to be expected on the first one.
Dustin
dusfor99 said:
No worries. 🙂
That is precisely what I need to do. So if your little app note covers it, well then hey I am happy. 🙂
Cheers!
Russ
Re: PCB top (preliminary)
Look forward to seeing this PCB in action. The layout looks clean. Just to throw this out there for everyone using the part, we have found that the MOST inportant thing in order to get the THD to be in the >-116 region, you really need a nice line of sight solid ground plane back the AGND_L and AGND_R. Basically, the ground plane should have as little inteuprtions to these returns from the load (the I/V converters)
Simply rerouting grounds we have seen 10dB differences in THD performance. If you care more for best THD, then only have 2Vrms or so on the output of your I/V converters (we got a board with all 8 channels to -120dB THD+N and full scale). (but sadly we lost a couple dB so they only operated at -125dB DNR on that board)
If you care more about DNR, then you want to maximise the swing on the output of the I/V stage since the signal gain is G and the noise noise is G+1.
Dustin
Russ White said:
Look forward to seeing this PCB in action. The layout looks clean. Just to throw this out there for everyone using the part, we have found that the MOST inportant thing in order to get the THD to be in the >-116 region, you really need a nice line of sight solid ground plane back the AGND_L and AGND_R. Basically, the ground plane should have as little inteuprtions to these returns from the load (the I/V converters)
Simply rerouting grounds we have seen 10dB differences in THD performance. If you care more for best THD, then only have 2Vrms or so on the output of your I/V converters (we got a board with all 8 channels to -120dB THD+N and full scale). (but sadly we lost a couple dB so they only operated at -125dB DNR on that board)
If you care more about DNR, then you want to maximise the swing on the output of the I/V stage since the signal gain is G and the noise noise is G+1.
Dustin
Re: Re: PCB top (preliminary)
Thanks Dustin,
It going to get a bit more busy now that I will need to add a uC. Still debating doing it on same PCB or separating it.
Cheers!
Russ
dusfor99 said:
Thanks Dustin,
It going to get a bit more busy now that I will need to add a uC. Still debating doing it on same PCB or separating it.
Cheers!
Russ
Separate it. Then make 2 versions.
1 that is basic that only uses SPDIF/SERIAL/DSD
1 that can support USB/Firewire audio streaming from a PC.
2 difference price points, and levels of complexity.
1 that is basic that only uses SPDIF/SERIAL/DSD
1 that can support USB/Firewire audio streaming from a PC.
2 difference price points, and levels of complexity.
Thanks Dustin,
Excellent suggestions.
What I am thinking is I may also want to do two versions of the DAC board itself. One that is simple, hardwired for I2S input (no uC required).
The other will be as shown (but corrected) and can use multiple controller PCBs (as suggested).
This way people who already have a I2S source don't need to be bothered with connecting a controller PCB. Of course the down side is they will be stuck with the defaults, which I am sure are fine.
Cheers!
Russ
Excellent suggestions.
What I am thinking is I may also want to do two versions of the DAC board itself. One that is simple, hardwired for I2S input (no uC required).
The other will be as shown (but corrected) and can use multiple controller PCBs (as suggested).
This way people who already have a I2S source don't need to be bothered with connecting a controller PCB. Of course the down side is they will be stuck with the defaults, which I am sure are fine.
Cheers!
Russ
Russ White said:
Russ,
You still may want a uC just to turn off the automute.
It is annoying. The default setting is short enough that automute engages in between tracks on most CDs. The automute mutes the DAC and then turns up the volume slowly when it detects a data point above the zeros. It cuts off the first note of many songs.
Sorry Dustin
but I have Automute turned off and it is much better. 😀
My biggest complaint about the Sabre8.
