Do I need a dac

Hello, 

The T2 is really great and great for the money as long as you use the internal DAC. 
The only thing I would suggest is a linear power supply. If you are out of warranty you can use a $400 SBooster. If in warranty you would void the warranty if using a LPS from a third party like SBooster. It makes a big difference. If you are willing to try a different preamp then Lumin just released the P1. It is an all in one preamp, DAC, and streamer with a LPS already built in. Plus, they say the sound beats ghe T2 and almost as good as the Lumin X1. I am in line to do an at hone demo. This store in the Chicagoland area is a Lumin/ SBOOSTER dealer. You can even demo the LPS for the T2 in your home. 
holmaudio.com

I think you would be good either way. I hope this helped. 

If I had your preamp, which I think is awesome, I’d get a better DAC.  Not that the DAC in the Lumin is bad at all and I’m sure it’s not, but I think you can do better depending on your tastes. 

I bought a aesthetix pandors eclipse dac and wow what a difference