How can a PS Audio Perfect Wave DAC enhance my system?

Presumably the PS Audio DAC would sound better than the DAC of the Marantz.

I suggest auditioning one in your own system to find out.  If your ears don’t detect an improvement, your wallet will thank you

1) the PS Audio DAC can be used with CDs, SACDs, and other digital sources.

2) many DACs can be used as digital preamps, because they supply enough gain to amplify the original signal of a digital source.  I owned a DAC like that and definitely preferred the sound with the preamp still in the system.  These DACs are not designed as pre amps and therefore tend not to sound as good as having a traditional pre amp in the system, but ymmv.

  As per my first post in this thread, I suggest you attempt to audition the DAC in your own system and let your ears decide.  There is an element of subjectivity in this hobby 

I2S transports the DSD output from SACD . TheTransport device--the extractor, in this case the Perfect Wave-needs to be able to send it to a DAC that has an I2S input.  The PS Audio DAC can also replace the DAC in your server for Red Book and other digital sources.

I play SACDs from an Oppo 105 Universal Player that sends the DSD via HDMI

to my DAC which has HDMI inputs. That isn’t your situation, since PS Audio doesn’t deal with HDMI, but for your information to let you know that it is available as an alternative.

Most dealers have a 30 day return policy. I can vouch for Music Direct being very good in this regard. You can order the DAC, try it for a week or so, make up your mind. You may have to pay some sort of shipping or restocking fee. I believe that PS Audio has recently gone to an Internet only purchase system, direct from the manufacture ( I may be wrong about this).. I haven’t bought any of their stuff since this happened but as bewgow above notes it is in PS Audio interest to allow their customers to audition their products so it is worth contacting them.  The major hiccup for you might be that you are not in the US; again calling PS Audio seems like you best bet currently to see what your options are

I am presuming that the PS Audio DAC has S/PDIF inputs so yes you can play Redbook CD.  You won’t be able to play the SACD layer of your small SACD collection so just continue to play them as you currently do