Hi,

I sent you a long email a couple of days ago talking about some trouble I've been having about maybe killing my spdif board, but much progress has been made since then. I've tracked the problem, and it wasn't the regulators; it was accidentally shorting DVDD from the slide switches because I misread the schematic/ordered the wrong switch . I've fixed that and now have the LEDs light up properly. However I'm not sure if this burned any components, mainly the receiver chip.

Last night I hooked it up to a cd player, and it mainly outputs this snowy noise, though at points you can hear bits of music VERY faintly in the background, and the noise stops when the music stops. This morning I hooked it up to my computer and it outputs noise no matter if anything's playing or not. Do you have any idea what would cause this/how to fix it? I replaced the buffer chip, but no change. Bad receiver chip/other component or Opus? I ordered the bare boards from you because I wanted to develop my soldering skills so I understand if you can't diagnose untested boards but any suggestions would be much appreciated. The last components for my USB receiver should be coming some time next week, so I don't have anything else to test the Opus with.

Things I've tried:
*Pin format on opus/spdif is the same as in the manual.
*Connected both grounds on the PS
*IVY works just fine and sounds excellent!

I can take pictures of my setup if it would help. Also I assume the crystal used in the SPDIF board is the same as in the USB board, correct?

And thank you for all of the work you've put into these thing! I'm pretty anxious to get this thing working.

-M

Hmm interesting, thanks for the tip. I tried playing it for a couple of hours though and no change.

I reordered some components so I'll try replacing those to see if it fixes the problem. If anyone has similar experiences or has any suggestions I'll be glad to try them.

Russ/Brian, one of the thing's I'm uncertain about is the regulators/oscillator I'm using. The regulator is TI's version LP2985A-33DBVT, and the crystal is a spare I ordered for the USB board since it looked like it had the same specs.

Thanks
-M

A few questions:

Did you build the Opus or get the pre-assembled module?

Do you have power lines running anywhere near the I2S lines?

A picture is worth a thousand words...

Snowy sound will also happen if the sample rate setting in the WM8741 does not match the incoming sample rate. For example I use Metro to emit 192KHz. If I set the WM8741 to Medium sample rate, I get snowy sound (more like white noise) and if I set to low sample rate, I get no sound at all. But I have not tested the other way around.

Here's a picture of the setup:



And the Opus:



Sorry for the crappy lighting.

Having OSR set at 1 causes nothing to play. Having it both open and set at 0 causes the noise, though 0 might be a little cleaner, I can't tell.

One thing I haven't mentioned is that the noise is a lot quieter compared to the USB's DAC (which plays at full volume)...is this normal? The clicks from the Opus in the one channel sound to be full volume.

Also, I notice when I turn it on, there's a quick burst of noise which fades out, and when I turn it off there's a small click and after a moment it sounds like a record scratching for half a second. I'm not sure if that means anything...it's a mystery.

-M

Alright thanks anyways mate. I'll try to replace the chip at some point.

I suppose there's no way to test the spdif receiver with the USB DAC though is there?