Preamp suggestions

I prefer not having a built in dac in a preamp / integrated amp, as dacs are ever so changing, and as much of an excellent design it could be, digital circuits, ime, can effect, badly, analog circuits. Down to the shared power supplies and power cords, keep them separate.

Mrdecibel makes an excellent point, especially for someone that owens equipment long term, rather than trading around every few years.  

Stumbled across a component fan. I never knew such a thing existed.

https://www.audioadvisor.com/prodinfo.asp?number=AYAC

Wow!  I didn't know such a thing existed either.  I just ordered the Parasound 2100 off of eBay last night.  Debating about new speaker cable and doing some research. The audiophile community is quite divided about whether high priced cable is legit. Strong arguments for each side. Seems to come down mostly to resistance more than anything else (i.e. materials, connectors etc).   Trying to decide about purchasing an external DAC but some folks are saying it's not necessary... Also debating about throwing my powered sub into the mix and pairing them with my Magnapan SMGa speakers or just sticking with my Snell's.  mcreyn you've been abundantly helpful with all of this.  

Congrats on the 2100, I think you will be happy.  

Cables-  You are correct, it is a big debate.  I believe that even among strong cable believers, it is agreed, that the difference between cables is minor in comparison to things like speakers, amps, dacs.  I have heard minor differences between cables, but never anything significant (unless you count a connection so corroded it barely worked).  At where you are, I would keep your cable budget low an focused on quality.  

Blue Jeans cable makes excellent cables for reasonable prices.  I also recently became aware that Zu audio sells overstock and NOS cables on ebay and you can often get a nice pair of speaker cables for less than $100.

External DAC-  It depends.  If you want to try, order a Schiit Modi for $100 (or Modi Multibit for $250), and see what you think  If you don't like it, return it within 15 days and pay the $15 restocking fee. 

Subwoofer-  It can be a mixed bag, mostly as I recall the Pinnicle subs not being the cleanest.  Worst case, try and take it out of the system.  Consider a good, inexpensive newer sub like the RSL Speedwoofer $400, or Rythmik L12 for $540.  Use the crossover in the Parasound, starting at a high pass of 80hz for your mains and low pass of 80hz for the subs. 

SMGa-  Owned a set for years powered by a Hafler DH-220 before moving on to larger Maggies.  A bit closed in the treble, but an amazing midrange, perhaps better than even current Maggies in that regard.  I think you will find they sound far better powered by the Nakamichi than the McIntosh, as the Maggies do like a good amount of power. 

Finally, setup, setup, setup.  Time spend dialing in the placement of the speakers and subwoofer, is the biggest difference in sound quality.   A $200,000 system with speakers just thrown in the corners will sound worse than a $1000 system with placements dialed in.  Read about the sub crawl for placing your subwoofer. 

ENJOY.