My answer would be in five parts -- based on extensive experience with two DCS stacks (Paganini, and Vivaldi)
Step one get that DAC on a stand pronto, has to be off the floor -- and never never stack the DAC on top of any other component (even another part of the manufacturer's own kit such as the DCS components)
Secondly improve the power cord to the DAC
Thirdly explore footers, I use Marigo Extreme F8 (expensive) -- the location of the footers on the DAC will have a large impact. In comparison with the stock footers (which are multipart squishy stuff and metal) the constrained multi-layer Marigo's sound much more relaxed, open and less congested -- not at all "lean". I also have had good results from bearing based isolating footers so you could experiment with these -- unfortunately as all will sound different the best thing to do is to get someone (like Ron at Marigo) who will loan you a selection and let you try them out
Fourthly consider placing a Shakti stone on top of the DAC over the transformer area
And finally look into the shelf itself -- I still have the stock perspex GPA shelves under my digital components however they have been treated with Marigo damping discs
Step one get that DAC on a stand pronto, has to be off the floor -- and never never stack the DAC on top of any other component (even another part of the manufacturer's own kit such as the DCS components)
Secondly improve the power cord to the DAC
Thirdly explore footers, I use Marigo Extreme F8 (expensive) -- the location of the footers on the DAC will have a large impact. In comparison with the stock footers (which are multipart squishy stuff and metal) the constrained multi-layer Marigo's sound much more relaxed, open and less congested -- not at all "lean". I also have had good results from bearing based isolating footers so you could experiment with these -- unfortunately as all will sound different the best thing to do is to get someone (like Ron at Marigo) who will loan you a selection and let you try them out
Fourthly consider placing a Shakti stone on top of the DAC over the transformer area
And finally look into the shelf itself -- I still have the stock perspex GPA shelves under my digital components however they have been treated with Marigo damping discs