Pass D1 - using i2s input

I don't use USB as source.
It is fundamentally foul, as it is not synchronised.
And then people invent all sorts of work-around to solve that.
I rather use a synchronised source in the first place.

I bought the JLSound just to be able to measure single chip distortions.
It was part of a measurement instrument, not a musical one.


Patrick
 
For a few years I sat next to an interface chip designer at my daughter’s karate lessons. I talked about designing a usb dac with him. His response was why? He said it was designed for mice and keyboards and everything else was bandaids put on top. I don’t know if that is really true but I am happy to buy someone else’s dac and not have to invest the time.
 
Yes, there is magic in SD card player as source and it is very hard to beat it with usb. Using that with the i2s lines reclocked gives a really excellent solution. Simpler the SD player the better I think.

However, USB can be very good with dedicated source, even if not the last word.
 
Yes you could input SPDIF with the XMOS board.

With the JLSounds board, you would input into U11-A, -B, -C for the right channel and similar for the left channel.

http://www.jlsounds.com/uploads/I2SoverUSB v.III.pdf


Mmmmm. So the JLsounds board arrived safe and sound and super quick. On first try I get only noise from the DAC. I believe I have the i2soverusb board connected correctly (triple checking) and the manual is pretty clear. Nothing only low level noise from the dac though. I was connecting it into U4 and U11 CLK, LE and Data L/R as appropriate. Software was recognising the board and I did a quick and dirty check, and there was some signal on each line to U4 and U11 (I do not have a scope, so this was just measuring the signal as if it was DC - not ideal but at least you know something is going). Just to check the i2soverusb I configured it for SPDIF and it works fine with that.

I need to think about this a bit more.....
 
So I have found one issue, but need some assistance on another. The first mistake was all mine - I was using a later revision of the board schematics, from the version after the one I have. So that was never going to work out. However, I have the right one now and just need a little direction as I'm ignorant as hell of implementation in these dacs.

So going back to Ben Mahs post above, the idea is to use the i2soverusb board which is configurable to output CLK, LE and Data L/R to the PCM63. As he mentioned, the i2soverusb output can be sent to U4 and U11. But when I do this, I get some background noise only. I have been connecting these lines on the inputs to U4/11 - should I be connecting them to the outputs instead? I've added the schematic here with arrows to show what I mean.....

Apologies in advance for what is probably an elementary question.
 

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Yes - i2soverusb is configured:

4.7k from H1.1 to H1.3
Bus power to USB side, separate supply to H3.17/H3.19
Jumper 4 closed, no other jumpers closed

Then taking outputs from i2soverusb to DAC 74hc86

H3.9 (DOR) to U11 pin 10
H3.13 (DOL) to U4 pin 10
H3.15 (LE) to U4 and U11 pin 4
H3.11 (CLK) to U4 and U11 pin 1
H3.16 (gnd) to a ground point on the DAC board

Photo attached of connections to U4, U11 is the exact same. GND point goes to ground point in the receiver section out of shot.

In the later revision (my first mistake) the inputs on U4 and U11 are different, but on this version they are the same on both.
 

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Looking at the schematics in 63v3_3.pdf, U11 is right channel. Left channel is not shown but I assume the equivalent is U4 from what you have written.

According to the schematics, for right channel, D0R (H3.9) goes to pin 10 of U11, and D0L (H3.13) should go to pin 10 of U4.

LE (H3.15) should go to pin 2 of U11 and U4.

CLK (H3.11) should go to pin 5 of U11 and U4.

According to JLSounds instructions, for PCM63, J4 and B5 should be closed. Edit: Not sure now about B5 re: on-board or external oscillators. If everything is connected correctly and still doesn't work, try B5 closed.

Also remove SM5847 as rfbrw suggested.

According to the schematics your DAC is balanced so there are two PCM63 per channel, and U11 feeds the right channel, and U4 feeds the left channel.
 
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Remove the SM5847 from the socket and see if that helps.


By George, he's got it!!

Yes removing the SM5847 fixed the issue and it seems to working well now.

Ben Mah - those U4/U11 pinouts are from the next revision of the boards I have (I made that mistake)....

But anyway, I have to say a huge thanks to all you guys for your really REALLY helpful suggestions. Sincere appreciation and thanks.

Fran