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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
erik_squires OP
16,128 posts
 
But I do not think we can measure what Herb R. says is 'human sounding musical pleasures'.


In this case, I actually genuinely think we can. My hypothesis is that he is enjoying the compression at the bottom of the dynamic range.

I'm going to see if I can prove this. :)

Stay tuned.

E

marqmike
839 posts
 
That would be nice if it could be correlated to what we perceive as 'human sounding musical pleasure'. Then it could be designed into our components. But so many, by my wild approximation of 250, systems I have heard most have a very small measure of that sound. Interesting topic Erik. I think it('human sounding musical pleasure')for me is a kind of core importance.
onhwy61's avatar
onhwy61
5,229 posts
 
The most common use of a compressor in music production is to reduce overall dynamic range by some combination of lowering the peaks and increasing the soft passages.  If uses judiciously it will bring out low level detail in a track.  It's a basic and widely used recording technique.
If the Border Patrol is manipulating the output signal to mimic a compressor, than it is not surprising that many listeners would like the effect.  An analogy would be upping the contrast slightly in a video signal.  There's no magic involved.
audioman58's avatar
audioman58
4,173 posts
 
That is a a pretty natural sounding dac ,the New Audio Mirror
is very similar and uses Vacuum tubes currently $1200 Outstanding ,Audio Analog Multibit dac which yourarely see anymore the Burr Brown 1704  dac chipsetcomes to mind.
way to expensive to make ,greatchipsets of the past 

mickeyb
578 posts
 
The border patrol is the best sounding dac I’ve heard. I found it very transparent and almost 
life like. I’ve not compared it to 10k plus dacs but some have said it’s the r2r arrangement. I’ve heard the denefrips dacs come close at twice the cost. Would like to hear the terminator. 
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