1.5 build report

A project log for TOSLINK DAC

Instead of a $10 box from Amazon, go above and beyond

Nick SayerNick Sayer 11/04/2021 at 19:270 Comments

The WM8804 decoder looks like a winner. The audio sounds just as good as before (which is hardly a surprise), but when muted there’s no hiss anymore.

Not only that, but the 8804 seems to be a chip very much in demand today - it’s one of the favorites for adding on to a Raspberry Pi.

So unless there are anymore surprises, I think this may be a final design.

If there’s a possible complaint it’s that the output levels may be just a tad hot. A 1 kHz 0dBFS sine wave winds up being about 6v P-P. Correct line level would probably be closer to what the CS4334 produced - about 4V (keep in mind we’re talking about an absolute peak level here).

For me, I’m satisfied to simply turn down the volume on the amp a little bit. I really don’t want to attempt to reengineer the analog out stage. If I were forced to reduce the levels, I’d probably just add an output pad. But I don’t think I will.