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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 3 responses by charles1dad

charles1dad's avatar
charles1dad
6,996 posts
 
Numerous posts on this thread attest to the very good sound quality of the Border Patrol DAC (BP). I’ve heard the BP and Benchmark (BM) although not in the same systems. In a general overall assessment the BP was more natural sounding and realistic IMO.

Herb Reichert’s rebuttal comments are exceedingly telling comparing the BP versus the BM. The BP captured and revealed master tape information /nuance completely missed by the BM DAC. in addition the BM struck him as harmonically threadbare, hard and cold (similar to my listening impression).

The BM has superior measurements and specifications. What does this yield? What is the benefit of the better numbers? Why does the poorer measuring BP retain critical master tape sonic and musical information that "disappears" when heard through the BM? It suggests that the ’superior measurements have little correlation with actual sound quality. Most experienced listeners already know this.
Charles
charles1dad's avatar
charles1dad
6,996 posts
 
Reichert is a very experienced listener and professional reviewer who additionally had access to the live Chesky studio and master file. He had access to both DACs and could compare directly.  It doesn’t get much better than this in terms of knowing the actual sound of the recording you are listening to. 

 He is quite adamant that he heard musical information that was present on the master file  and subsequently conveyed convincingly with the BP .  The BM was notably inferior  under these listening circumstances according to him..  he simply and honestly reported what he heard. I don’t believe for a moment there are any ‘mind games’ being played here.  

One may not like the results of his listening sessions but he is reporting what he experienced.  In this scenario one DAC was clearly found to be better than the other, in this case the better sounding DAC happened to be the BP 
 Charles
charles1dad's avatar
charles1dad
6,996 posts
 
I had a very similar Spectral experience (Dr. Keith Johnson controlled the room) with them  driving Avalons at CES in the late 1990s. The sound quality was threadbare,  mechanical and artificial in my opinion.  About 30 minutes after this demonstration I heard in another room the exact same Avalon model speakers driven by Jeff Rowland electronics. Substantially better, natural and very emotionally involving relative to the Spectral components. Much more instrumental realism.  Those Avalons really revealed the stark sonic differences between the two brands. I wouldn't be at all surprised if the Spectral components had the superior measurements on a test bench. Hearing both there was no comparison.
Charles 
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