Playback Lag on RPI 2 with Hifi Berry Dac +

I am running a Rpi 2 with the dac + pro with a wired Ethernet connection. I have a decent nas that is definitely able to stream music to the pi without slow downs. My libary is fully indexed and the CPU usage is low however the songs still occasionally stutter. They play fine on my various windows machines from the NAS. I have tried changing the playback buffer however this made no difference apart from lag upon selecting songs. I am not sure what else to try. The CPU usage of the Pi whilst playing sits around 2-3% so I can’t see how the CPU could be the bottleneck.
all help is greatly appreciated

Just curious. How are you connecting to the NAS files?

I have tried cifs and nfs and both have the same results

As long as you can play the files locally (from a physically attached storage device), then you know the Pi and the DAC are not the issue. The problem likely lies with the network or the protocol. I have never had great streaming results via NFS or Samba on Linux. I avoid using either. I stream everything via DLNA from Plex. Does your NAS support DLNA/uPNP?