Tube or R-2R DAC for Tube System

@jsal3689 and others with Denafrips Terminator experience, I am about to home audition the Merging+NADAC. I am wondering why I'm not seeing it mentioned in most DAC chains? Do any of you have experience with the Merging? I am wondering what I may be able to AB with the Merging while I have it, but only if you have found something superior or equal in terms of air and realism. One note on the Merging, and what sold me on it versus others having observed it in the component stack in countless videos from hifi shows / events. It must be worthy if so many speaker manufacturers, etc. selected it for their demonstrations? It's top of the mark, price wise for me, so I need to make sure it's going to be the best bang for my buck. I hope this adds to this chain as something to consider since the terminator plus was mentioned and a piece I seriously considered, and may yet.

My SET w/ KT 88's and Denafrips Ares 2 ($800) is fantastic. Soundstage goes Waaaaay back behind the spkrs. talk about holographic. Or the Pontus is double the Ares2 in price w/ slightly better performance.

there seems to be some confusion with terminology.  Multibit = R2R.  They can be discrete resistors soldered onto a PCB or thin or thick film hybrids on a IC; but they are both ladders, and both take in PCM and spit out PAM.

Bitstream is a different animal, based on pulse density modulation.


Arguments can be made for and against chips based R2R but the real reason for the proliferation of discrete DAC is that R2Rs vanished from the market place long ago.  AD has re-introduced one that is used by several, including Schiit, but it is not designed for audio and glitches.

Whether you place a tube I/V and filter after it or the same deal with transistors is an independent question.  tubes of course help get glowing reviews (ducks for cover after bad pun).

@itsjustme,
Do you have any particular opinion regarding I/V conversion method, i.e. passive (resistor) versus active. Transistor vs transformer vs OP-amps?
Charles

Learning now!  Entirely passive seems like a tough proposition since the output will have a variable impedance and a high one at that.  For a home/hobby project where you can control the next stage maybe its feasible - but in commercial proactive that sounds, to me, like suicide.

Transformers are a natural for the task, but are typically big and expensive ( and most that are not , are not very good) . I have not experimented with any custom ones.  I plan to use discrete circuitry, combining FETs and BJTs where each as an advantage - and keeping it pretty simple. (what was it that Einstein said? "as simple as possible, but no simpler" :-)

The output characteristics of bitstream DACs vary quite a bit too- some only give a voltage output - meaning an onboard opamp i presume. The real world gets messy.   But again, still learning. All my DACish work so far has been on the other end of the chain - input, isolation, clocking etc.