Apogee Duet 2 vs O2/ODAC

[r010159]

I owned an O2/ODAC for several months. That was the first time I heard a transparent amp that was fun to listen to. But I tried to correct what I heard with some music by trying plugins to warm up the sound. It has this "edge" to some sounds. On some vocal passages in the higher registers, like with Enya, there is a type of "distortion" that can get on the way. This also can show up with Bob Seger singing Hollywood Nights with his gravely voice for instance. And the sound can come across a bit "thin".

 

I next tried the Apogee Duet 2. I immediately noticed that a soundstage can have depth. This really threw me for my initial time with this unit. I also noticed that "edge" to sounds disappeared and has a more "refined" sound with better nuances in its place. Saxes come across not raucous like they can with the O2/ODAC. There is a different tonality between the two units, the Apogee much nicer. But I cannot define what is this difference in tonality.

 

I am trying to describe the differences which I only partially can identify and understand. I cannot put my finger on the differences in tonally between the two. But there is an obvious difference to me. Can anyone help me by making ann attempt to understand what I am trying to say? How about relating what you notice as the differences in this tonality between the two?

 

Boy, I am hard pressed to discern the differences that I am hearing.

 

Bob Graham

[Sam Lord]

Bob,

 

A while back you wrote, "There is not much 'magic' and technical 'wizardry' that goes into the design of a DAC."

 

I'm sorry to say that you won't be able to correlate sonic results and electrical phenomena, given your statement above. DACs are exceedingly difficult to design; only really exceptional teams of engineers are capable of equaling, let alone beating a current design at an equivalent price.

 

So you must rely on metaphors to help you. There are lots of accepted terms for describing nuances of sound reproduction. I think the best route for you to learn those is to spend time hearing truly first-rate systems. You can either find a store with a really fine system in place (very rare), or go to a demonstration at a really good venue with well-constructed, quiet rooms. Consider RMAF for that. If you happen to be in a big city, one of the audio societies would be your best bet. It is quite easy to point out audio distortions after you have heard a great system for a long time. IME the first thing that will grab you, in a couple seconds, is dynamics. The second is honest soundstaging. The third, tonal truth, comes right afterwords and those 3 things really define the experience. All other sound features, whether positive or negative attributes, are subsets of those, IME.

 

Good luck.

[pooger]

I fully agree with what Sam has said. I also think you are asking about the "lingo" of reviewing audio, and along with educating your ears, reading good reviewers can give you a better vocabulary to describe what you are hearing. Not only that, once you have the vocabulary, your thought processes can become more specific (we do analytical thinking in a verbal fashion) to help you discern what you are hearing.

 

My son has an O2 that I made last summer as a portable amp for him. I tricked it out with very closely matched parts, and it is a good headphone amp. Not great, but great for the money. And I think that with some headphones that are easier to drive, it can be great.

 

I don't have direct Duet2 experience, but have used Apogee's rack equipment, and it's very very well designed and built. I've also listened to a good amount of music made using Duets, and can say that the Duet sounds pretty darn good. I'm sure that the DAC part of the duet is in another class above the ODac. Harder to say (for me, not having listened to it), if the built in amp is any better than the O2. Plus headphones and amps are hugely synergistic.

 

Anyway, getting back to my original point--find some reviewers that you understand and like. They don't have to be current; other than jitter and digital artifact discussions, you could go back to 1980s Absolute Sound and read Anthony Cordesman, et al. You're looking for long, in depth write-ups that may include technical explanations of why something sounds the way it does--but mainly well reasoned and explained subjective assessments that will give you a linguistic framework.

[r010159]

I guess I was wrong. I have never heard anything better than the O2, and understanding just the basics of DACs, I thought it would be straightforward to implement. I guess I am expanding my horizons and seeing things differently now. But I still cannot understand what is so difficult with implementing a well-performing DAC. There are DAC chips that do most of the work.

 

Bob

[pooger]

I guess I was wrong. I have never heard anything better than the O2, and understanding just the basics of DACs, I thought it would be straightforward to implement. I guess I am expanding my horizons and seeing things differently now. But I still cannot understand what is so difficult with implementing a well-performing DAC. There are DAC chips that do most of the work.

 

Bob

 

A DAC has 4 basic blocks in it: a receiver to get the signal from the computer and send it to the DAC circuitry, the DAC circuitry, which outputs a signal that typically needs conversion, an analog stage (usually I/V, but not always, and a power supply that gives everything the clean current that it needs to do its job. What the DAC chip does is, in ways, the least important of the four, because the chips are easy to implement, and very inexpensive (for the most part). So the other three blocks of parts are the ones that have the greatest effect on sonics. (Basically, you could take great version of these three and make a good sounding DAC with any of the current chips that get used. Some would be better than others. But you could take the best chips, or even other technologies that get used for the D to A process, and mix them with sub par power, input, and analog stages, and still get a poor sounding DAC. From a cost point of view, the power supply is the most expensive.

 

There are certainly other issues—construction quality (board technology and layout, vibration and shielding, mechanical quality of the inputs and outputs, that all can add or subtract from the sound quality. It's anything but easy. If it were, then the markets for higher end equipment would dry up pretty fast.

 

Again, Sam has some great advice—listen to some top notch systems, get a sense of what is possible (if not affordable ;-)) and keep an open mind.

[pooger]

PS—I think you are actually on your way to doing a good job of describing what you are hearing.

[Audio_ELF]

Well put...

A DAC has 4 basic blocks in it: a receiver to get the signal from the computer and send it to the DAC circuitry, the DAC circuitry, which outputs a signal that typically needs conversion, an analog stage (usually I/V, but not always, and a power supply that gives everything the clean current that it needs to do its job. What the DAC chip does is, in ways, the least important of the four, because the chips are easy to implement, and very inexpensive (for the most part). So the other three blocks of parts are the ones that have the greatest effect on sonics. (Basically, you could take great version of these three and make a good sounding DAC with any of the current chips that get used. Some would be better than others. But you could take the best chips, or even other technologies that get used for the D to A process, and mix them with sub par power, input, and analog stages, and still get a poor sounding DAC. From a cost point of view, the power supply is the most expensive.

 

There are certainly other issues—construction quality (board technology and layout, vibration and shielding, mechanical quality of the inputs and outputs, that all can add or subtract from the sound quality. It's anything but easy. If it were, then the markets for higher end equipment would dry up pretty fast.

 

Again, Sam has some great advice—listen to some top notch systems, get a sense of what is possible (if not affordable ;-)) and keep an open mind.