Is it worth it? DAC question

Hook up a USB cable from Node to DAC. You don’t even have to go into Node settings to enable USB output. Listen and you decide. 

OP,

It really depends on which Node you have. The Node 2 and Node 2i DACs aren't very good as previously mentioned, the DAC in the Node 130 is better. Some have recommended the Teddy Pardo LPS, but at $425 is rather expensive. I use an LHY LPS which at $279 is more cost effective, and for me yielded surprisingly good results.....however I have a Node 130. Only you can tell which DAC is better on SQ

+1 on the LHY LPS (I have an N130 too) and gong with an external DAC. 

*going with...

+1 kmcong

I have had a similar path with my Node 2i

I have moved through 4 different external DACs.  Going RCA out of the Node to my Preamp makes my system sound so dry, dark and without detail.  My progression of DACs all gave an improvement.  I also went through 4 different RCA cables, a 30 year old Audioquest to a new Audioquest Carbon which was a huge improvement.  I next got a Cardas Clear with was noticeable but not as huge...kind of what you would expect from the law of diminishing returns...sometimes those mid-level leaps have the most bang for your buck.  I recently moved to a previous gen Transparent Reference 75ohm and it again gave a noticeable improvement over the Cardas.  The Node N130 and new X both have digital out of their USB port where previous models it is only a file input connection.  Some claim USB is a better way to transfer the signal to the DAC.  I called Transparent and while they cannot speak to specific models and configurations of a system, they feel 75 and 110 ohm RCA is superior to USB.  I have decided to stick with what I got until I am ready to make the leap to Aurender or dCS to have an all in one and eliminate the need for this cable.  Have fun experimenting with external DACs...they will be great upgrades.