Add a Linear power supply or iFi SPDIF Purifier2?

How many volts ? Please keep in mind you have to know the amp output also 

go to small green computer . Ijust put anice lps on my new modem router combo  the power supply made a Big difference the music has much  better image densitt and focus. My new 8702 Motorola has a much better 4 core processor andBig memory buffer and verygood wifi ionlyuse for control ofthe tablet ,

a huge upgrade alsoistheSonore Ethernet toFiberoptic  the Sonore deluxe is $500 each , for now youcan get one and just add LPS  to them noise cannot travel over fiber optic much cleaner then wire , 

Yes using fiber optic is the best medium for isolation , the Sonore Deluxe is much better ,I started with just a media converter , the big difference inside there are linear technologies low noise regulators ,choke, and very low jitterFemto clocks 

the $40 ones will work but have high phase noise you should at minimum at the end point spend $499 for the Sonore, Small Green Computer  sells them and has very respectable LPS power supplies the 12 v  model I bought for my rougher is 

6 lbs for $300 is a great buy , these too take about 100 hours to settle in but it is now much clearer ,more depth and the top end bite is gone , after theLPS  the aftermarket  DC cables and a inexpensive pangea powercord , these tweaks add another $1k to the mix ,I have 3 LPS for the 2 Sonore deluxe media converters , and forthe New Motorola 8702 modem-router ,with the much faster 3.1 Docsis technology Big sale on AMA         Zon.

You can go from Ethernet to fiber optic to start ,then upgrade at your pleasure.

the sonore deluxe converter should be your end of chain for $499: $$ well spent .

one step,at a time.