Next best exponential DAC quality level?

 That’s like saying once amps reach a certain point there’s no difference.

Once they do, there isn't. 

@djones51 — you’re absolutely delusional.  ASR is calling.

Why this toxicity?  This is easy to show.  @djones51 is correct. That does not mean you can pop out one op amp in a circuit and just replace it with a "better" one. The circuit must match the op-amp for best performance.  Within the limits of their performance envelope, you would never be able to tell many op-amps aparts, even some relatively inexpensive ones.

So many love the old pre-digital recordings. Do you know how many cheap 5532 and 5534 op-amps were in the signal chain before you got that record?

@phill55 My preference is in the following order ...

Luxman DA-06> Audio Mirror Tubador 3 > Node 2i

It's too early to comment on the differences between T+A and Luxman yet. 

One thing I did not mention earlier was that right around the time I bought the Luxman DAC, I went through a number of DACs in a 6 month period. Based on stellar reviews and great measurements, I bought the Topping D90. It seemed to do everything right ... on paper. Probably my least favorite DAC, despite it measuring better than many others. At first it impressed, but I just couldn't connect with my music emotionally. It never moved me. I would get bored after maybe 30 minutes of listening. 

Then a used Luxman DA-06 showed up in the used market and I decided to give it a shot. Now mind you, the DA-06 is at least a 6-7 year old design. Within the first 30 seconds, I knew it was a keeper. Sold the Topping within a week, no regrets. There's a reason DA-06 still commands $2k or more in the used market.

However, the best DAC that I have heard in my home is the one that is included in Audio Research GSi75 integrated amp. The level of finesse and balance on that DAC was outstanding. I ended up selling the GSi75 for other reasons but sill miss that DAC.

At the end of the day, it really depends on what one is seeking. If specs and measurements are the end all and be all for you, then more power to you. I see the usual suspects - the graph-readers, the 'everything sounds the same' crowd has raided this thread in full force. The rest of the discussion will only go one way now. No further comments from me. Good luck!

I listened to a DAC for the first time in 1984. That was two years after the arrival of the first CD player to the USA - the Hitachi vertical-loader. In 1983/84 Adcom came out with the first made-in-the-USA audiophile CD player, soon followed by the Adcom  DAC. That's what I listened to in a high-end store. Sounded pretty good - but no cigar! I went back home to my turntable and LP collection. I waited until 1992 to buy my first CD player - a Technics using the MASH circuit. Up till then I didn't think that digital could compete with analog - the reason that I waited ten years to get into digital playback.

That first Hitachi CD player sounded good in 1982 - and at a retail price of $1000 it should! But no cigar! That high-end store had the TOTL Denon TT/arm/mc cartridge into the Levinson JC-1 head amp clone. No.contest - LP playback was clearly way better! I think it took about 10 years for consumer-level CD playback to challenge the LP (1991/92).

There isn’t a person in all of this site (or any other site) that could tell the architecture of the DAC if designed to be accurate just from listening.

That’s absolutely correct. Then why do you and others keep insisting that a tube based DAC is inferior, has poor SQ compared to SS? Oh yeah, it’s the specs.

An example of a well built, well implemented DAC is made by Audio Note. The designer has said they measure and spec the device, then they tweak it during a listening session until it sounds like real music. They use masters as their sources.