I believe @hilde45 upgraded to LPS on his Node. Don't recall the name. There may be other threads on that or he may chime in.
While I have a different streamer, trying the iFi iPower Elite, comes in 5, 12, 15 and 24 volts. Their marketing claim to fame is "improved Active Noise Cancellation II® actively cancels all incoming noise.", "Quiet as a Battery", etc. Over time I've noticed a nice dark background and it seems like it might be more quiet between notes vs. the stock wall wart unit.