Seeking Advice on NOS DAC

@jond, he didn't reply and the ad ended. I emailed the store and it's still for sale, so we will speak via phone call.
Jim

@jl35 , always great reviews for the Exogal. I know it uses a FPGA, does it have a laid-back presentation? Not looking for anything "in your face." As I stated, need a dac that faithfully presents Redbook.

Thanks, everybody. I should have mentioned that I auditioned the Schiit “Gumby” and it sounded a bit too aggressive in my system. Excellent dynamics and soundstaging, but my system is very revealing and it wasn't what I was looking for.
  I've owned a Chord with FPGA and found it very smooth, so the Exogal Comet Plus is on my list. The FPGA that reshapes the waveform is a major advance in DAC technology.

Because of the low Input Sensitivity on my tube amp (1V), I'm limited to a DAC with good volume control or one with low output voltage such as the Metrum Acoustics Hex.

And thanks, David. I'll check out the Darko DAC index. I like his reviews.

Thanks, @jond . I will certainly start reading about this DAC.

Thanks guys, both DAC's look interesting. And @whart  , the Border Patrol does "check the right boxes."

@jond ... Enjoy the Music gave the DAC2.1 Signature a  phenomenal review. It looks like everything I could ask for in a DAC.
My only issue is the review is from 2005. So I'll ask you, what type of questions should I ask the seller/dealer?
Condition of caps and the tube circuits come to mind. Also, there is no USB input.

Oh, wait a minute. I just saw a pic of the DAC2.1 and it only has balanced-outputs. My system is SE tubes and I don't know if I want to use XLR adapters.

Many thanks to @mitch2 and @acresverde . The Pavane will probably be out of reach (even used).
In addition to multiple positive reviews, Darko really liked the Hex. And there are two currently for sale; I may stretch my budget to $1650 for the right DAC.

Thanks, @jond . I messaged the dealer with some questions. I asked if any service was performed and if the original electronics were intact (very high-quality components are used).
I'm wondering why this unit is so reasonably priced, so I asked for pics.

Can anybody recommend a USB/spdif converter? And wouldn't this signal need to be reclocked and the 5V power be isolated?

Red, everything you've stated is consistent with my research, especially about timing or "ease." Every pro and user review loves the Comet, but NOS seems to have what I'm looking for.
Right now, the Audio Note and Hex are the contenders. But I need advice regarding a high output DAC going direct into my tube amp (1V input sensitivity).

This may be a silly question, but is it helpful to use a reclocker before the input to a R2R DAC? I know the reclocking device should not do any upsampling.

I believe your 1V input sensitivity means your amp/amps achieve full output power with a 1V input.

@mitch2 , that's correct; 1V at full power. Regarding the Hex (2V unbalanced), I'm sure it will be a fine match as far as impedance and amp input sensitivity.
Let me give you the back-story, I'm using a PS Audio Nuwave DSD with 2.8V output and I believe it is driving my amp into clipping (sounds like distortion thru speakers). I have a thread posted about jitter control in which several members stated that I'm experiencing clipping due to the low 1.0V input to the amp. At first I thought the harsh sound was due to jitter, but overdriving the amp makes the most sense since it only happens on loud passages, such as a crescendo and close-mic'd brass.
My amp has a nice feature, a direct input with variable gain control; but only up to 1V max. Input impedance is 100 kohms.

I have an Atma-Sphere SE preamp that I take in and out of the system, and there is the same distortion sound during loud passages.
I actually checked other SE tube amps such as Quicksilver and CJ and they have 1.0 input sens. I guess when paired with a preamp with the right amount of gain, it works well.

I have been looking for a NOS DAC with analogue VC and haven't seen a suitable one yet. As far as the Jade and the Adagio, they would be ideal, but none are listed yet in the used market.
I appreciate you keeping up with me on this thread.

Thanks @mesch . And now Schiit makes a converter.

@georgehifi, Border Patrol has a good rep. I like seeing the quality parts being used, but no hirez from audio files?

@chayro , thanks, I'll check out the Doge. I'm not all about specs...R2R DACS don't really measure all that well. But they do have a nice organic sound.

"most NOS chips support 24/96"
That's true, thanks.

@audioengr , I'm using a PS Audio PWT for 16/44.1 playback. USB from my Mac. SPDIF cable is 1.5m from Empirical Design. 
I'm wondering if any reclocking would be beneficial and if upsampling would hurt the native 16/44 input stream to an  NOS dac.

That’s right George, Redbook is my priority. And I don’t wish to convert PCM to DSD. But the NOS DACs Ive been looking at will play 24/96 or 24/192 downloads from my hard drive thru USB. I know, I know it’s possible they won’t sound any different than 16/44.1.

Computer audio is secondary to me, but I’ve been adding music to my library. And some downloads are misrepresented as hirez, but I'd like to explore this new to me music.

@rodge, it sounds like you're saying the AN 2.1 Sig. is worth persuing.
I plan on asking if any of the high quality electronics were replaced under the hood.

Thanks for the tip on the usb-spdif.

Thanks @chayro . Looks VG for a good price.
I've been thinking about steering away from the ESS Sabre and looking for older multibit or proprietary processing such as the AN.

AN makes great stuff, but I think you’re falling into the trap of believing the chip makes the sound....
I think part of AN’s philosophy is to filter and alter the signal as little as possible

I’m not at all saying the chip makes the sound. It’s just that I’ve had a couple ESS Sabre DACs and they seem to excel at retrieving detail, granted the implementation of the total component plays a part. I’ll add that I only have experience with $2000 and under DAC’s in my system.
In the dac’s that I’ve owned or auditioned, IMO, the analogue stage gives the component its signature sound. And less filtering in the digital and analogue stages helps.

I’m starting to like what I read about the Border Patrol. It’s possible that a good NOS DAC can reproduce Redbook plus 16/44.1 downloads better than than 24/96 files.
I do have one concern regarding the Audio Note, the AD1865, 18-bit Dac chip has long been out of production, so I wonder about service. Chips don’t fail very often, but I still think about it.

@jond , yes you're absolutely right about that.
So, finally heard back from the dealer; waiting for pics of the innards. If all goes well, I'll make a purchase.