Single Ended DAC vs Dual Differential XLR DAC

Measurements, done correctly, do not lie.

Nor do they the whole story.

I believe that most audio purchases are made with relatively little prior listening, and are based on reading reviews. Many of those reviews are highly suspect and involve little in the way of critical listening or critical comparison.

Agree with this big time and is a HUGE pet peeve of mine. TAS is a main offender of not doing any relevant comparisons or even disclosing what equipment is in the review system and I’d never rely on one of their “reviews” to form an opinion on a product. However, there are some good, rigorous reviewers out there who I find very helpful, so it’s important to find the more reputable reviewers out there and just ignore the trash.

You will get a better s/n ratio and a cleaner, clearer signal with a fully balanced unit.  That being said, if you do not have a fully balanced system, it is unlikely that you will get the full benefit of this.  This is largely due to the fact that at some point, the balanced signal will be converted to a single ended signal when it hits the unbalanced component.  Common mode noise rejection is lost and the quality of that transformer will have a BIG impact on sound.  

That transformer is often why, single ended devices sound better when using RCAs rather than XLRs with a transformed signal.  It is also why balanced devices XLRs almost always sound better than the RCAs that typically accompany the units.

If your system is fully balanced, you should get a fully balanced DAC.  SE will never sound as good.  If your system is single ended, a fully balanced unit will sound as good as a single ended unit at best.  Pay a lot of attention to the quality of the output of the RCAs if you get a fully balanced DAC.  Brands like Bricasti and Weiss have virtually no difference in performance between XLRs and and RCAs in practical terms but those are more the exception than the rule.  Many others see signal degradation in that XLR to RCA transformer.  

The reason the circuit is duplicated, (4 chips vs. 2 chips, etc...) is driven by the need to produce the inverse for common mode noise rejection.  That extra chip does not increase resolution, etc...

@verdantaudio ,

The reason the circuit is duplicated, (4 chips vs. 2 chips, etc...) is driven by the need to produce the inverse for common mode noise rejection.  That extra chip does not increase resolution, etc...

While that may be true in this device, where the noise is so high that nothing will fix it, using two DACs in a balanced configuration will often result in an improvement in THD+N/SNR as non-linearity is averaged between the two chips.

I think you need to explain more about the transformer you mention. I assume you mean an external transformer based single ended to balanced converter?

Unfortunately, there is no guarantee that balanced will sound better. It all comes down to the implementation as you have noted, and it takes more components and it is harder to do properly than a single ended connection. You are pretty much always guaranteed to get better noise/emi rejection, but I would be cautious about that blanket statement w.r.t. distortion.

You are right...being sloppy. If all you are doing to convert an SE signal to XLR is adding an "inverting amplifier" you will not get all the benefits of a device being "balanced" and depending on the quality of that section of the amp/premap/DAC, etc... you may get degradation in quality. This is where you can get the phenomenon of RCAs sounding better than XLRs in non-balanced equipment.

If the entire circuit is fully balanced, then it will be cleaner sounding but if the components that balanced signal is being sent to are not balanced then all that excellence is lost.

In practice, this shows up in DACs. Take the Rockna Wavedream SE vs. XLR. In a fully balanced system, the XLR DAC will outperform the SE. In an SE system, the XLR and SE will sound the same.

@verdantaudio ,

I think you are interchanging balanced and differential but perhaps do not mean to. "Balanced" would refer only to the connection. Differential would refer to the circuitry.