[Armaegis]

If You don't care about quality that's Your business.No stacking when replacing one switching unit with a line power supply.One replace on the other.

I care about sound quality as much as the next guy around these parts. I don't know why you would assume that I don't simply because I didn't evaluate this dac with your favourite power supply.
I have stated the procedures and associated equipment of my review. Adding aftermarket products into a product review are not terribly useful as they are not necessarily easily accessible nor desirable to the next consumer. The cost is significant, and the size increase is likewise significant compared to the stock psu.

Awesome job man. I just got a Yggy Analog 2 in, looking sexy in black but ADI-2 DAC isn't going anywhere. It is such a versatile piece of hardware in an incredibly small package.

I haven't heard the new analog board yet, but boy howdy is it on my list of wants.

 

[lowvolume]

Apparently someone doesn't understand how it positively affects the sound replacing the switching supply to a linear power transformer.It is perfectly audible and visible on exact measurements of noises.

You can measure differences of noise at the power supply outputs, but not at the ADI's analog outputs. Not at all. If linear (hum inducing) supplies are your cup of tea - no problem, but don't expect others to follow stone-age technology myths and complicate their setups for zero gain.

 

[lowvolume]

And here is the proof:

https://www.audiosciencereview.com/...eview-and-measurements-of-rme-adi-2-dac.2582/

 

[LuckyNat]

Thanks for the review/comparison - am only just coming across the ADI-2 now and looks a fantastic bit of gear I can both use for recording and enjoy fully for listening.

I wanted to add to everyone's knowledge though...

and also a unique "Loudness" setting which to my knowledge is the only implementation of the loudness function done properly.

The Meridian 601 DSP pre-amp released in 1992 (!) did this too and also had a headphone output. 26 year old DSP !

 

[Armaegis]

Hah, thanks for sharing that obscure little tidbit!

 

[LuckyNat]

A pleasure! I had a stint of collecting the Meridian 600 series 12 years or so ago, just to get a taste of a 90's well-off person's world in my living room. Still got the CD transport but the rest passed back to ebay land whence it came.

The most annoying thing about that 1990s DSP is that you could only run one DSP process at a time - too little processing power available.

 

[Phoniac]

According to this unit's manual found here:

https://www.meridian-audio.info/public/601um[1475].pdf

it had a 'threshold' value to define volume, similar to the RME. But else I would say it failed, because it used a tilt-style tone control. You could not set up bass and treble boost as your ears need it. Only either bass OR treble boost. At least that is what I find in the manual.

 

[LuckyNat]

That manual online is crazily small! Think I have the original somewhere.

The Loudness function has the tilt tone control overlaying the loudness EQ - so set it at 0 and it just does the loudness curve without any tilt . I guess the tilt overlays a bass/treble tilt rather than changing the loudness curve itself? I'd have thought the loudness curve was set in stone based on psychacoustic principles and Meridian folks are/were clever folks.

EDIT: I just re-read your comment. Seems like it is set up like the RME, like you say.

 

[BLacklWf]

Great review!! Subscribed!!

 

[Phoniac]

@LuckyNat: yeah, to be really sure what they did we would need measurements, it seems. The RME stuff is 100% documented and explained in the unit's manual.

I think that using the equal loudness curves to perform such a compensation alone will fail for several reasons. First no one has the exact curves as shown there. Second they do not reflect the current state of hearing based on our demography, with society getting older and older. Third treble loss with older people (eehm, 50 up, sorry) or people that suffer from the Walkman syndrome does not work like a low pass - it shows a threshold, that is higher as usual. Did you ever do a listening test? They generate sine tones and ramp up the volume until you hear them. When you are young the threshold of hearing is very low, and at very low volume. But when you get older the threshold in the higher areas rises. That means you don't hear the tone, and the next moment you hear it - really loud! Consequently you need to listen to music at a higher volume to enjoy the sound quality, and when you reduce the volume just a bit all the glare is gone, for others it already sounds totally dull.

The RME version is flexible enough to allow for compensation even of the threshold-dull effect so that music sounds nice again at lower volumes. The sound will not be exactly the same as when hearing with higher volumes, obviously, as their solution does not address the underlying threshold-effect correctly. I wonder if a solution addressing this effect will ever exist, though.

And I wonder about the expertise of some. Just read that Dr. Floyd Toole has written a book where he states that Loudness should ONLY address bass. He can't be more wrong than that.

 

[LuckyNat]

Just to come back to this - refound the thread after searching for Callia reviews - as far as I'm aware, there is a technically accepted (continuous) set of "loudness" curves that varies with level . Adherence to the algorythm (or theoretial circuit ?) that produces those EQ curves *is* Loudness done correctly by definition. In other words "Loudness" is a thing that is defined and stops at the basic EQ curve vs level.

What it seems the RME then does is allow personalisation on top of Loudness done properly. That is to say that Loudness done properly has been done before in consumer gear, even as far back as the early 90s, but perhaps not this *extra* level of personalisation which make Loudness work properly for everyone, one set up.

 

[Armaegis]

Loudness in the past was simply an adjustable knob (or simply a switch) that tuned the bass and treble. In effect, it was a static EQ applied.

On the RME, it is a dynamic EQ that changes depending on your volume (and you set both the threshold at which it begins, and the maximum size of the curve). The quieter you make it, the more the loudness curve kicks in.

 

[Phoniac]

No offense, but I find your description/explanation misleading, especially 'static' and 'dynamic EQ'. The former loudness versions were a fixed EQ setting that was blended in with the current volume setting. I wouldn't describe this as 'static' as the EQ effect does change. And it is not different to the RME, and their implementation is not 'dynamic' at all. The difference between former and RME's loudness is that the user can shift the range where the loudness effect will be audible to whatever volume reference. That is a big difference to 'old' implementations where the effect had a fixed reference level and often did not match the listeners needs of bass and treble amplification for the perceived volume. Loudness has always been an EQ that varies the gain of bass/treble with the volume setting. RME went one step further and also allows the user to adjust the bass and treble gain in detail, which can better match the listeners expectation. But all this had been explained a few posts back already.

 

[Armaegis]

Tomayto-tomahto. I'll agree that fixed is probably a better word than static.

Most old implementations of Loudness were a fixed EQ that boosted the lows and highs. This boost would apply regardless of where your volume knob was.

The RME on the other hand gradually applies the loudness curve depending where you are on the knob. When you are at high volumes, no loudness is applied. The softer you go, the more the loudness curve is applied. You can set the shape of the curve, as well as the upper and lower thresholds for where the curve triggers.

 

[Phoniac]

Most old implementations of Loudness were a fixed EQ that boosted the lows and highs. This boost would apply regardless of where your volume knob was.

I have to disagree here. I have never seen a unit where Loudness was NOT coupled to the volume knob position. And I have used many devices in my life with that function. You have an example of a unit where Loudness is really 'fixed'?