Absolute top tier DAC for standard res Redbook CD

In fact, the Aeris is currently a bit bright if anything.

Bright as compared to what? I based my thoughts on your response to the MA-1 in particular. That is not typically perceived as a overly bright or hyper detailed dac but can reveal crappy Redbook files for what they are:

File density. Primarily, increased data density seems to net greater ambient retrieval. Space appears. With it the venue acoustics turn 'wetter'. Minuscule reverb interactions come more to the fore as performer auras. Reducing file density from 24/192 to 16/44 dries out the apparent acoustics. This puts the focus on just the performers. It eliminates much contextual data which previously interfaced the performers with the physical space in which they performed. It's quite similar to overdamping a room. Lower resolution mirrors higher damping and how too much absorption progressively kills off not just room reflections but also the musical charge or energy of the playback. In that sense hi-rez isn't about more primary stuff. It's about more secondary and tertiary stuff. Short hand might call that a lot more audible space.

A parallel perception is of greater fluidity. Lower resolution appears stiffer and starker. As resolution increases, more nuanced microdynamics flow into this feel. That greater differentiation of micro swings translates into more ebb and flow, into greater inner motion and from there into greater listener e-motion. Finally treble performance becomes more sophisticated particularly with as revealing a tweeter as the Raal ribbon in my Aries Cerat Gladius speaker. But the most profound benefit from higher resolution—at least to my ears—really is the superior ambient recovery or dimensional context.

DSD vs. PCM. The dsf/dff files compared directly to their PCM equivalents all exhibited the same slightly sweet slightly soft texture. As perhaps a deeply PCM-engrained listener who couldn't make the quick transition, I soon related to this as an admittedly pleasing but nonetheless minor coloration. Sharing this with Morton, his terse reply was comforting. Exactly my experience. There's a kind of Hollywood soft focus to DSD. Those who concur to prefer high-resolution PCM (someone could acknowledge this DSD effect but be partial to it*1) might refocus from streaming DSD to playing back PCM at up to 24/352.

Sixmoons

Thus the need for a slightly softer SS or tubed dac particularly in light of your room and primary source material.

Brightness is of course subjective, however there are some key things in a DAC design that can cause this perception:

1) out of balance dynamic response

This occurs when the power subsystem cannot respond exactly the same speed to a low-frequency transient as a high-frequency transient. Low frequency transients require power reserves. High-frequency transients require fast regulation and low ESR decoupling caps. Even though the DAC measures perfect for frequency response, the dynamic response can be and usually is out of kilter. It requires both excellent voltage regulators as well as optimum mixes and locations of decoupling caps to achieve the correct balance.

2) Compression

Compression is when the active stages, whether discrete, op-amps or tubes cannot react linearly under all circumstances. Circumstances such as high energy bass, high-level signals or fast transients can sometimes push active stages too far and they cannot react linearly. They may behave differently when amplifying low-level signals versus high-level signals. Local heating in integrated circuits or current sharing in the on-die power distribution can cause this. Power supply and decoupling can also play a role. Reflections of significant power back to the output driver can cause it to go non-linear (see #3).

3) insufficient output drive or reflections

The output drive must have low-impedance. It must behave the same when driving difficult loads and easy loads. However, like a high-Q cable, a low output impedance and fast slew-rate has its downside: It must be critically damped for HF reflections. Many DACs do not have any termination and this can cause harshness at the leading edges due to HF reflections. Even though reflections are an RF or digital phenomena, these can occur on the output cable. The question is whether these affect the behavior of the output driver or not. It is best to put a treatment there to address this IME.

Steve N.
Empirical Audio

AGear - Thank you for your input. I am, by no means, a professional reviewer and appreciate your six moons quote as it better describes the MA1 in a more objective description then my own. If you could maybe provide some links to professional reviews for the gear I am auditioning it would be appreciated and helpful to the group at large. I have neither the trained ears, acoustically corrected room, expansive vocabulary nor elocution to properly review gear in the objective manor in which the pros can do it.

As I said when I started, I am simply saying it like I hear it with no bias other then what sounds best to me, in my room, with my ears. What I heard from the MA1 lacked emotion as compared to the Aeris and OverDrive. It did not engage me the way the other 2 did; I spent more time analyzing and less time lost in the music. To me it was not simply a matter of bright or dark, nor analytical vs slurred. I think in a different system and a different room it would shine, but not mine. I would also imagine that for a reviewer it would be an ideal DAC as it is miraculously accurate in both it's soundstage, imaging and reproduction of tone.

My apologies to all for the limitations in my room, my ears and my ability to objectively convey what I hear with the gifts of a reviewer. As Popeye said, " I ams what I ams...."

But I'm getting closer to my objective and having a damn good time doing it, and talking with some really good audio guys along the way like my new friend AGear, Charles1dad, Merrill, Audiolabyrnth, Steve, Guido and 2 dozen other guys. Isn't Tay what it's really all about?

Matt, you have nothing at all to apologize for since you made your intentions very clear. You have been up front about your specific situation and objectives (i.e. only being interested in a DAC's 16bit/44kHz performance.) Your efforts are still very helpful to many of us and appreciated. Keep up the good work and glad to hear that you're still enjoying the process. Sometimes such evaluations can become tedious and less than enjoyable for many of us with less patience than you obviously have.

Matt,
A big attraction to your thread is the honesty, don't change that, continue to call it as you hear it. A friend of mine who has heard many DACs described the EmmLabs just as you, he didn't care for it. Everyone has an opinion about something, some love this and others love that. Matt just do your thing and continue to enjoy the experience.
Charles,