Best tube dac available?

I'm about to purchase Magnepan 1.7's, will power them in my law office with a World Audio Design K5881 Class A tube amp (because my office is not large and loud volume would be a problem) ... I am shopping for the 'BEST SOUND PER DOLLAR' Tube DAC, to use my iPhone, as well as the 'BEST SOUND PER DOLLAR' Tube Preamp ... further, I have a Dbx III, and would like advice as to whether the Dbx is a reasonable additional means to expand dynamic range of iTunes from an iPhone ... Thank you, all. GeorgeTheLawyer@post.harvard.edu

I dunno if I would go with so many tube components in one system :)

Try to listen to them in combination and see if you like them

not all tube dacs have the same "flavor" and when considering bang for the buck, much subjective judgment goes into suc an assessment.

as i have said before, wavelength and the original zanden are my favorite dacs. unfortunately, both are expensive.

since all tube dacs have different degrees of "tubeyness", it is wise to be more specific as to your sonic requirements.

I really love the LampizatOr Lite 7 DAC.  It's quite amazing.  Having heard Lambizator's top of the line Golden Gate DAC at AXPONA, I can highly recommend it.  

http://www.ayllonmedia.com/1/post/2015/06/the-lampizator-lite-7-dac-a-high-performance-machine-or-a-bloated-beetle.html

http://www.ayllonmedia.com/1/post/2015/05/axpona-presents-audio-con-2015-an-audio-celebration-on-steroids.html

Modwright Elyse - 6922 signal tubes and 5ar4 rectifier (swapped NOS of both into mine) - excellent dynamics