I seem to have ended up with a very expensive DAC, without really intending to. In fact, the DAC I have would probably be regarded as obscenely expensive, even compared with the very expensive DACs I have previously owned. The value of my DAC is multiples of the next most expensive component in my system, and about 5 times the cost of my speakers.
My DAC is a Nagra Tube DAC, with Classic PSU. You can google the cost of these, and I say this not to brag but to indicate how shocked and surprised even I am by the amount I have spent on this DAC. I did not quite pay the full new price, for reasons I will explain, and got there in stages. In fact, strictly speaking it is not a Tube DAC but an HD DAC which was internally upgraded by Nagra to Tube DAC internals, although it still says "HD DAC" on the faceplate.
Is it worth it? In an absolute sense, no. Of course not. A DAC cannot be worth that much money. It is hard to justify on any rational basis. Do I regret the purchase? No. I spend a lot of time listening to digital - maybe 8 or more hours a day while I am working, and probably the same amount when I am not. I have been through a lot of DACs over the last decade or so, many of them very expensive by most standards. All of them have been vaguely unsatisfying in one way or another, until the Nagra arrived.
Some of the DACs I have owned include all of the Chord DACs: Qute, Qutest, TT2, QBD76 and DAVE, and I have owned the M Scaler no less than 3 times. I had an Ayre QX5, a Mytek Manhattan, a Metrum Pavane, a Holo May, a Meitner MA1 and a bunch of others that escape my memory. Immediately before I bought the Nagra, I spent a week with a DCS Bartok on loan from a dealer. Although I had it for a week, I could tell within the first few minutes that I would not like the Bartok. It sounded impressive - big, dramatic, realistic in some ways - but also lacking in tonal colour and dynamics. It sounded quite monochrome and was just not musically engaging for me. I returned it after a week.
When I was at the dealer I noticed there was a traded in Nagra HD Dac. It was offered at a bit less than a new Bartok, and around the same price as a new DAVE. I disinterestedly asked the dealer if it was worth listening to. He shrugged and offered it to me to listen to if I wanted to. A customer had traded it in for a new Tube DAC. I borrowed it without much in the way of expectations.
When I connected it at home, it sounded good. In comparison with the Bartok which had been there a couple of hours before, it was bursting with tonal colour and harmonic complexity. But in other respects it sounded quite ordinary. It sounded "smaller" than the Bartok, less dramatic. But I listened to it for hours without fatigue. After a week or so, I bought it.
I compared it with my Mytek Manhattan II, which I still had at the time and which I still regarded highly. I actually went back and forth with the Manhattan for some months before I ended up selling the Manhattan. In direct comparison, the Manhattan could sound a bit sharper and faster, with slightly more defined edges of notes. But it also had a certain thinness to the sound. And while I liked its sound, it did become fatiguing after an hour or two and I lost interest in listening to it (just as I did the Chord DACs and others). By contrast, the Nagra was never fatiguing and I was able to listen to it for hours without pause.
Like many, my reference is vinyl, although I am fully conscious of vinyl's limitations. Noise, limited dynamic range, as well as limited range of music are inherent in analog audio. But even a relatively modest turntable can sound deeply satisfying over a long period - despite these limitations - in a way that most digital does not.
The thing I noticed - or indeed failed to notice - about the Nagra DAC was that it sounded quite ordinary, but managed to achieve a similar level of deep musical satisfaction. It did this without over-emphasising any particular aspect of the sound. The DAVE/M Scaler by contrast sounded hyper detailed in a dramatic and attention-grabbing way but was ultimately unnatural and fatiguing. The R2R DACs had a lovely fully bodied tonality, but sounded heavy and dynamically slow.
Over time I upgraded the HD DAC to the Tube DAC internals as mentioned above, and bought the Classic PSU to replace the pair of ACPS II power supplies that came with it. I bought the VFS support which was also a noticeable improvement.
I have now had the Nagra DAC for about a year and half, which is longer than most DACs last in my system. I have no desire to replace it, and still listen to it happily for hours at a time. When I do get a chance to listen to another DAC, I am often initially impressed by some characteristic of the new DAC, but over time I notice that this characteristic, which was initially attractive, now becomes obvious and a source of fatigue. The Nagra quietly sits in the background, knowing that I will return to it.
After buying the Nagra DAC I also bought a used Nagra VPS phono stage, which is also powered by my Classic PSU. This has similar characteristics - nothing obvious stands out, just a natural, musical and engaging quality which slowly becomes addictive. This seems to be a Nagra trait - well engineered equipment which is not designed to impress on the first listen, but which sounds natural and which slowly insinuates its way into your consciousness.
So, for me, the benefit of getting a very expensive DAC was at last to find something that sounded "ordinary". In other words, digital music that sounded like real music without any unnatural artifacts that make it difficult to listen to for long periods, or reminded me that I was listening to computer-regenerated music, which was the case with every other DAC I have owned. I had to pay a lot money to get something that did not draw attention to itself and just played music in a satisfying but self-effacing way. I still think it is in many ways unfair that I needed to pay so much money to achieve an outcome that was so "ordinary". But now I am glad that I have.
No doubt there are other very good DACs, many of them at much lower cost. I haven't heard everything. But having spent far more than I ever thought I would on a DAC, I am for the first time satisfied with digital as a format for playing music,.