DAC Measurements vs Actual Experience

Big difference between accurate and personal preference. The Benchmark may be a far more accurate DAC, but that does not mean for you it is the better DAC.  If you have some ability to set absolute volume though, try to listen at exactly the same volume. One thing you can be confident in, you are not doing anything wrong.

One particular way in which the PS Audio DAC purportedly falls down is the level of noise, possibly due in some way to the use of a transistor output. I confess that I'm not well versed in circuit topology and the idiosyncrasies of certain configurations, but the reviewer from Audio Science Review speculated that that could be the cause.

Another shortcoming is the somewhat limited dynamic range as compared to the Benchmark. I was especially concerned about this given that I have inefficient (86dB/watt/m) speakers. If my logic is correct, a diminished dynamic range with those speakers might make it more difficult to distinguish transients and also some of the more subtle inflections in music. So far, this hasn't borne itself out in my real-world tests. But that's one way in which I'm doubting my own hearing. *Should* I be able to tell a difference here between DACs? 

The level of detail that each DAC is able to extract from the program material, at least as far as I can discern, is virtually identical. The female vocals in the final 2 minutes of Roger Waters' "Amused to Death" has been my go-to challenge for a component's ability to convey delicate nuance. Neither DAC has demonstrated any apparent advantage. 

As far as stepped volume control goes, the DirectStream touts a "bit perfect" digital method. I'll take their word for it. I'm not sure what the Benchmark's configuration is, but I cannot detect any deterioration of performance at any of the levels I've tried (all further clockwise than the 12 o'clock position). I'm evaluating each at the same volume, or as close to the same volume as possible, such that I cannot tell the difference. I'm sitting in a quasi-near-field position relative to the speakers (~6 feet away), mostly using a volume where the system is conveying energy convincingly, but falls well short of concert-level volume. Evaluations have also been made at more "whisper" levels with volume control being done using my streaming device.  

The differences that I'm honing in on have more to do with grain, soundstage and the admittedly vague descriptor of "musicality" than anything else. But I have this nagging feeling that I need to be listening for something more; something that enables me to look at my experience critically compared to the measurements and say, "Ah, yes. There's where my perception is supported by the data." And yet, that's not happening.

These two units each bring a very strong game. I would probably be quite happy with either of them. And yet, I don't want to get this decision wrong. Maybe what I'm asking for here is a "listening lesson" from experienced audiophiles. But to the larger issue, do perceptions and measurements often disagree? 

Yes perception and measurements can disagree. I'm a measurements guy and I also like accuracy, I had a Benchmark DAC3 and liked it I found it very "musical ". The only reason I sold it is I got a new integrated amp with room correction and I really couldn't tell a difference between it and the Benchmark. The PS Audio as you mentioned doesn't measure well it has more noise in a way it is more like vinyl or what a lot of audiophiles say warm, analog like, natural etc.. which isn't uncommon for poor measuring DACs. Some prefer that sound, it's more what we grew up with and associate with sounding right. I will probably get jumped on with what I say they often do, there is nothing wrong with liking what you like or preferring and following your perceptions instead of the measurements don't get hung up on how it measures. Another thing you could try is listen with your ears and not your eyes. Try to get someone to help out and listen to the DACs blind it might surprise you. 

Yes, of course, perception and measurement can, and in many situation, actually WILL,
 disagree. WHY?

In my experience it is something to take as a ’given’, something to accept - not easy actually.
Something even more hard to learn is, the level of ’SQ limitation’ of one’s front-end feeding one’s speakers - THIS includes your cable/system synergies, big time!

Something I had to learn quite recently after over 25 years of looking - in the wrong places too.

In my case, I had taken for granted that my Transparent Ultra, pre to amp, was ’beyond reproach’.
Turns out that was not quite so!

A more like accidental change, of this item (Transparent), for a Madrigal HPC XLR (25 years old!) affected my digital (and analogue) performance most profoundly!

Former harsh like digital sounds, trying to mellow down (make mor 'musical') by e.g. CDP interconnects, using another DAC, with very pricy Transparent Reference digital interconnect, and on - all was of rather marginal outcome.

The ’right’ pre to amp interconnect, all of the sudden, ’changed’ digital harshness into... previously unheard DETAIL, AIR, TONALITY, CLARITY etc.! 

So, the looking for more ’warmth’ in digital reproduction, in this case turned out to be just a band-aid for low cable/system synergy.
This is just an example for what can happen if one ’looks’ in the wrong place - based on some long held assumptions.

I hope this makes some sense, as its not a very easy thing to get accross.
Michélle 🇿🇦

Thank you all for your insightful responses! 

The synergy between components to one another and the interconnects between them, as mentioned in Michélle's response, is something for which I have great respect. Sadly, it's often blind luck that ends up fixing the problem for me. At least in this case I have an apple to compare to another apple, and I *know* the specific component in the system that's responsible for the change in sound. My collection of audiophile quality cables is small (limited to the Nordost Blue Heavens that I'm currently using, a few offering from Tributaries that have never really sounded good to me, and a few sets of Mogami Gold that mostly see use in the music studio). I feel that, while adding cables to the comparison might not be useful at this point, I might swap them out later in this process and see what the results are. 

The sound of the PS Audio is not what I'd call vinyl-like. And I hesitate to describe it as warm. It definitely has the flavor of a solid state device, but manages not to be "out front" nearly as much as the Benchmark. Again, the level of noise isn't perceptibly different than that of the Benchmark in my current system, which is to say that I cannot detect any noise whatsoever in either DAC. 

And with that in mind, I've decided to swap out the Magnepans for Klipsch LaScalas and see if an extremely efficient horn speaker can shed any light on the noise and dynamic range issues. Or, at the very least, see if any differences are revealed between the two DACs in those specific categories while using the other speakers. Who knows? Maybe that will bridge the gap between the measurements and my perception, even if I may actually be getting to the point (albeit slowly) where I no longer put a premium on measurements in choosing audio components.