What would be good preamp to run McCormick dna1

Agree with a Tube Preamp, but not a lean sounding one that sounds like SS. With the DNA 1 w/MG3a’s you need a preamp to wake things up. Plenty nice affordable preamps out there and I bring it up every time because for the money I still think it’s The King; Modwright SWL 9.0 SE has PRAT. The little Modwright has a basic remote too. If you don’t care about a remote and on a budget, older Conrad and Johnson preamps are very nice. 

Hafler DH110. Excellent SQ! Available often for less than $200.

Another good budget choice is the PS Audio 4. I have two! Quite affordable!

I'm driving a recently completely upgraded DNA-1.0 with a Mark Levinson Model 26 preamp. The results are very good. My speakers are a pair of restored German Physiks Borderlands MK1 which like high current SS.       

I had dna1 with rev a mods long ago with Vandersteen speakers. All I can suggest is what I owned with DNA. First was Rouge 99 magnum, BAT vk 5i se and Don Allen preamps. My favorite was the cheapest which was Don Allen, they pop up every once in a while in $500 range used. The Rouge was next with top end NOS tubes. The bat just never seemed to match well, maybe because it sounded more solid state than others to my ears.