Crane Song Solaris Quantum for $2K from Sweetwater. It is the sound of analog which is diff from neutrality which you asked about but you will be totally pulled into the sound.
The Nagra HD DAC is neutral based on comparing with master tape but at a quantum leap in price compared to the Crane Song. Your likely reaction is that the Nagra is more laid back than the Crane Song. To make an analogy to which prolly one 0.001 % of readers can relate it's like the diff between 468 and 456 tape. 468 is neutral to the point where upon first comparison you find it dull compared to 456. But upon long term listening you find it is more relaxed which is why a lot of pros go for 468. Especially for recording classical.
* difficult to get Crane Song. I guess it's three guys working out of a garage. Sweetwater is yr best bet for getting yr hands on some actual bird.