To DAC or not to DAC ?

Lots of good banter here...

I can recommend considering the RME ADI-2 DAC FS.  You need to Google this one because saying it's a DAC is a substantial understatement.  In fact, I got mine as much for its headphone amp and its DSP features as for basic conversion.  If you have significantly different hearing, L vs R, plus would like to enjoy your headphones with a massive leap in enjoyment--it is a MUST consider.  Once you go German, you can't go back--it's verboten :-)

It initially used AK4490, later on the AK4493 (I have this one in mine).   Last I knew, new production used ES9028Q2M for its supposedly high-quality DA conversion. I have read this chip is similar to the AK4493 in features and technical specifications, which must be why RME continued without a model number change to the ADI-2 DAC, kept its quality, and with only slight change in features.

@decooney

I attribute the lack of significant difference between the GW and WE tubes to them being in a tube buffer output. I wouldn’t expect a tube to make as much difference as it potentially could in something like a Jolida FX Tube DAC. I am using a 3 foot Blue Jeans Cable silver plated coaxial cable. On a whim, I opted for the silver plated cable vs. their standard copper version.

Take a look at the Simaudio 390 or it's predecessor the 350. Excellent preamps with very good DACs on board. Really, it depends on your listening preference. If your world is digital it's worth going bigger. The 390 gets you a full use preamp, for not too crazy money. Both it and the 350p are highly regarded. I would agree overall your preamp is most likely the thing to upgrade first. 

I have owned a McIntosh C220 for about 10 years.  Absolutely love it.