Looking for a new DAC

You want a highly resolving, linear measuring DAC with Magnepans because Maggies roll off the top octave considerably. You don’t want anything that truncates those fine details further. 

IME, for such a DAC, there is no need to get anything more expensive than the Topping E70 Velvet. If you’re inclined to spend more, try a Mytek or used DCS. 

https://forum.audiogon.com/posts/2789441

I can attest to the benefit of adding the DDC to the LAIV Harmony DAC. I found the LAIV DAC on its own to be decent with neutral warm but fairly detailed sound but lacking something. A little too vanilla with just average sound stage width, height and depth. There was also a kind of lack of focus. The DDC cleared that all up. It became very focused, tightened up but not restricted in any way. Actually the opposite. It opened up in all 3 directions, became richer, more lively. I am going to see if an iFi iPower2 power supply on the DDC will help even further but I’m a bit skeptical. I’m quite happy with the sound or of this setup. Using Anthem AVM60 as preamp, Moon 760A power, Wilson Sabrina X speaker, dual REL S/812 subs, Denon DCD-S1 CD player, Magnetar UDP800 for SACDs through cheap HDMI to I2S converter.

With the myriad of responses you've already received, mine may not provide a whole lot of value. 

My prior system consisted of Magnepan 1.7s, a Rogue Audio Cronus Magnum III stereo tube amp, the BlueSound node (2, then 2i, then n130) and outboard Schiit Audio Bifrost 2/64. Once I left the Rogue Audio integrated amp, there were some gaps I needed to address in warmth and preamp signal matching.

I first upgraded to the Magnepan 3.7i set and the sound stage opened up, but again the upgrade from a Rogue CM III to an Audio Research VT220 and Schiit Freya + left me wanting. The sound was amazingly warm, but lacked power in the mid bass and most anything resembling rock music, which I like a lot when not listening to jazz or blues. 

So, I installed the Schiit Tyrs and that addressed a huge gap when driving the 3.7is. After an upgrade of the caps on the Freya + and a bunch of preamp tube swaps, I began realizing the next iteration of improvement would be improved clarity and it wasn't coming from the preamp or amp. The Node and Bifrost were okay, but my feeling was they presented as muddy. So, I upgraded the DAC to a Bricasti M1 and while it helped (especially as I compared it to other DACs), I felt like it wasn't worth the upgrade cost (even used) and that's when a local audiophile and reseller said "Hey, your streamer isn't in the same class or architecture capabilities as your other gear. It's likely holding the DAC back, by a lot." After pushing back a few times on what appeared to be a selling bias, I asked if I could return the U2 if it wasn't improved. He said yes, so I bit. 

Well, that was an unexpected and huge upgrade. The clarity is there, resolution has improved, sound stage has widened, and now I'm looking for the M1 upgrade, so I can upsample up to and more than DSD128.

Good luck on your project and I hope it never ends :)