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The Border Patrol DAC - Maybe linearity in a DAC is bad ... Spitballing

Hi Everyone,
I've been thinking about a few things related to DAC's and how they behave and how we hear. Also thinking about a couple of audiophile comparisons I've heard and how we interpret what we hear.

Let's talk about this simple measurement called linearity.

In a DAC what we mean is that as the magnitude changes the output changes the same amount. That is, if the signal says "3 dB softer" you want to get exactly 3 dB softer output on the jacks.

And with modern, top tier DACs this is usually really good until around -90 dB where noise becomes the limiting factor.

For a long time I felt that a DAC which allowed me to hear the decay of a note, so that it fades instead of stops suddenly was the mark of a truly excellent sounding DAC.

I'm wondering if what I'm actually hearing is compression? Lack of linearity.

The reason I bring this up is that I was reading a long article about the complexities of reviewing a DAC from Border Patrol. One of the main failings, from measurements, is that it is really not linear at all. Sounds don't get softer fast enough. And ... low and behold, Herb Reichert actually makes many comments about how much more he can hear with this DAC than with others.

I'm going to link to a critique of the "scandal" so you all can get a better look:


https://parttimeaudiophile.com/2019/01/06/border-patrol-dac-revisited-audio-fur/


Also, take a look at the linearity charts in the original review. Honestly, awful. Not up to what we expect in state of the art DACs today, but ....


https://www.stereophile.com/content/borderpatrol-digital-analogue-converter-se-measurements

What do you all think? Do we need a compression feature in DACs so we can hear more details? That would make more sense to me than a lot of the current fad in having multiple filter types.

Best,
E

erik_squires

Showing 4 responses by nonoise

nonoise's avatar
nonoise
11,142 posts
 
@mzkmxzv,

You hydrogen based life forms are funny. Anyone can be tricked, even those who adhere strictly to measurements. It is with long term critical listening that we appreciate the differences and distinctions. 

Quick switching (A/B/X, whatever) is nothing more than a cheap parlor trick. Even your ears would be fooled into thinking you're hearing an excellently measured piece of kit about half the time when it's not.

Sighted references are just that and no amount of back seat psychobabble will account for all the situations as there are people who can overcome the stupidity of listening tests because they do have better ears. It's statistically inevitable that they can. Do the math since you're so good at it.

Also, all of your anecdotal evidence is just that. For every story you dredge up, there are those that prove the other point of view. And please, everyone, don't let someone dictate what "cold and sterile" is for you as mzkmxzc states.

For me, it's an unemotional and dry presentation. It can be full of bass and have what most would consider a normal treble but where it fails for me is a deficit of tone, body and timbre: a threadbare presentation. It simply won't pass the test of fooling anyone in an adjoining room or even off to the side  that something live is playing. It will measure well but it will not sound right.

All the best,
Nonoise
nonoise's avatar
nonoise
11,142 posts
 
@gwbeers, 
Nice analogy. My father was a film editor back when they used film. Towards the end of his career digital was coming on scene and he hated it. It's implementation lagged way behind the promises. 

Today it's great but back then, as a child, even I could see how bad it was.

All the best,
Nonoise
nonoise's avatar
nonoise
11,142 posts
 
Erik:
Don't let the objectivists hear you say that. They would consider it blasphemy and subject you to something jagged, or worse.  😄

All the best,
Nonoise
nonoise's avatar
nonoise
11,142 posts
 

From the Stereophile review, a rebuttal from the first reviewer:

In order to answer that question, I have purchased and studied at least 80 genuine (analogue) “master tapes” taken directly from the archives of RCA. Many of them I played back on the exact Ampex machines they were recorded on (which I also purchased). Virtually all of them sounded VERY “pleasing good” and therefore, by your definition, must ALSO have sounded accurate good. In truth, I can’t remember hearing too many bad sounding master tapes.

For my reviews I always use high-res “master” files supplied to me by the recordist for that purpose. When I finished my BP/BM comparison, I told JA about my own “alarming audiophile episode” with Macy Gray’s HDTracks album “Stripped,” wherein the BP DAC reproduced pretty much exactly what I heard sitting behind the binaural head at the former church in Greenpoint and the Benchmark DAC3 which did not even get close. It conspicuously stripped away a huge amounts of what I and David Chesky know is on the recording.

I use Chesky recording sessions to review headphones because I can compare what I hear live to the sound coming off the so-called “mike feed.” The Border Patrol DAC reproduced the church walls, the reverb, the positions on the floor where the musicians were standing, and all the subtle breathiness of Macy Gray’s voice. With the Benchmark, the majority of that information (which is definitely on the master file and appears via David’s $100K MSB DAC and via my Holo Spring DAC) disappeared !!! Your neutral DAC “stripped” away information that is unquestionably on the master file. Not to mention the BM DAC made it sound hard cold and harmonically threadbare. I call this subtractive distortion. Did you measure any of that?  


It’s all in the ear of the beholder.

All the best,
Nonoise
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