OK. So what type of filtering is needed then, with those DACs? Is it as Ken Newton said earlier?
The recommended filtering is done with 2nd or 3rd order active stages around opamps. However those filters (shown in most of the DSs) are designed to give ultra-low noise for the spec sheets (lower noise is one of the marketing highlighted features) and hence use lowish value resistors to minimize noise. In my experience loading the outputs of DACs in this way squashes dynamics - I prefer to buffer the DAC prior to filtering its output.