While DSD is a patented Sony technology and the SACD is the format jointly developed by Sony and Philips, they have licensed the technology to other brands like Denon, Yamaha, Onkyo, Pioneer, etc. So even the chip used is often shared and every brand is free to put in enhancements of its own to differentiate its products. Some brands don't use the DSD chips and elect to convert the DSD bitstreams to LPCM prior to the DAC to lower the cost. That is why you can see some ads of some brands banner "genuine or true SACD decoding," to differentiate their products from those that do PCM conversion.
DVD-A is a whole lot simpler as it is just a more dense implementation of PCM technology. OTH, the circuitry for DSD decoding is admitedly quite complex as the algorythms to process the huge stream of data can be very elaborate. Forget about the 1-bit word-length, it's the 2.83 MEGA hertz sampling rate that is too much for most DACs. Let alone using DSPs to process such enourmous data for bass management and channel delay compensations that are required for proper SACD playback. Now the landscape is changing, thanks to newer faster chips. But even those expensive Denon universals convert to PCM when bass management is engaged. And their proprietary D-link digital interface doesn't even pass digital SACD datastreams, though I read that's also being addressed. I am not even sure if SOny universals have the proper bass management for SACD without resorting to PCM, maybe their flagships.
It isn't a rule that SONY alone makes good SACD players, their entry SACD and mid-level models are often as limited in bass management and channel delay features as other models of the same price range. I won't even say that going SONY is the safest route to SACD, though there was some justification to that in the past.
Perhaps some new more affordable universals with proper SACD bass management and other features will come out next year.
