Delta Sigma DACs

Thanks everyone, that pretty much confirms what I thought.  Now here's the rub: I have a Cambridge CXU that I bought to play my CDs, and to play any SACDs and HDCDs I might want to add to my collection.    It has an onboard DAC with 5 Wolfson WM8740 chips, which use the Delta-Sigma decoding scheme.  I use it only for 2 channel audio, and have it connected to the line inputs of my preamp.  It plays Redbook CDs fine, presumably through the Wolfson DAC (the user manual is hopelessly incomplete).  I had wondered how that worked, but georgehifi's response addresses it, and makes sense to me.

So, you would think that it would be a cinch for it decode SACD's, right?  WRONG!  I recently got my first hybrid SACD, and when I put it in the CXU... nothing.  No sound.  After several email exchanges with their tech folks, they said that I could only play it if I set the "SACD output format" to PCM.  That does give me sound, but I can't figure out if I'm listening to the Redbook version or the DSD version on the hybrid disk.  Why on earth would they require me to use the PCM setting to play a SACD disc through a Delta-Sigma DAC?  Am I missing something here?

Again, SACD is a product of Delta Sigma converter and in order to convert it to analog you need filtering and not another Delta Sigma DAC. I’m afraid you’re stuck with Redbook layer. Your Cambridge CXU can output digital only as S/Pdif and this format won’t work for SACD.

I’m afraid you’re stuck with Redbook layer. Your Cambridge CXU can output digital only as S/Pdif and this format won’t work for SACD.

I don't think that's correct; where did you read that?  The Cambridge site says it plays, among other things, SACD and HDCD formats: https://www.cambridgeaudio.com/usa/en/products/cx/cxu

If it was only capable of S/Pdif, how could it play SACD disks? 

@shadorne 
Then why do R2R DACs sound better than Delta Sigma?

Then why do R2R DACs sound better than Delta Sigma?

In fairness, better or worse sounding is somewhat subjective and at the discretion of the ear of the listener.

That said, and based on the relatively few delta-sigma and multibit DACs I’ve heard, I prefer multibit as it is more authentic and not as digital sounding to my ears.