[the terabyte]

Associated equipment: AKG K1000, Etymotic ER-4S, M-Audio Transit, Hosa interconnects, DIY Hifi Chazz with KT88 power tubes.

Music/sound preferences: I listen to almost everything, this "review" is a result of general observations and not direct comparison. I find this to give a better overall representation. In terms of sound, I love the K1000 tonal balance and character. I want dynamic, lively sound, without losing touch with reality.

About a week ago I received my RME ADI-2 24bit/192KHz AD/DAC. First the pictures, which I know you all appreciate:

Inside

The DAC is the AKM4395 , the same that is found in the E-MU 0404 and AKM's top of the line (discounting the 4396 which supports DSD).

The headphone output is centered around the JRC NJM4580 opamp. The power section (also in this photo) accepts anywhere between 8 and 28V, DC or AC (RME does sell a battery solution, I believe).

The ADC is the AKM 5385. I don't have anything to test this with, unfortunately.

Introduction

Well, I'll start off by saying that not since I bought the K1000s have I heard this much of an impact in terms of how much the sound changed in my system. Some people find that source upgrades are the kind of thing that you need to listen to for a while in order to appreciate, but this was slap-in-the-face "wow I can't believe it sounds this good" as soon as I plugged it in.

For those of you skeptical of the context of such claims, I understand. Thus, let me explain my source path to this point. For quite some time, vinyl has been my main "real" source and has brought me great pleasure. Most of my vinyl collection is classical, but I do have most of my favorites on LP (assuming they exist in that media). I have dabbled with digital in the computer-as-a-source style, first with a modified ART DI/O and then with various sound cards. None of these digital devices ever made me think "I'm glad I bought this, this was really worth the upgrade." Thus, I have for the past couple months been on the lookout for something more satisfying.

My price range was not great, but my tastes were specific. I had an Echo Indigo which I liked the general sound of but that didn't sound "real" (and so didn't work at all with classical. I suppose it sounded similar to classical through my old SR-325s). Thus, I read up and finally decided to try out the Bel Canto DAC 1, after hearing reports of its smooth yet detailed sound that appealed to me. Needless to say, the DAC 1 was a huge disappointment. For a while I struggled with it, forcing myself to listen (this must be what it's supposed to sound like, right?). No good came of this, though.

The unit was modified, so I thought perhaps something was wrong with the powersupply, but after thoroughly inspecting and measuring it this isn't true. The sound just wasn't what I was after and thus it was sold after but a few weeks.

Now, on the prowl for a sub-$700 DAC that would fit my tastes, I spied a thread discussing the ADI-2, which, people reported, used the same type (AKM) of DAC my beloved Echo Indigo uses. And so, once I saw the Bel Canto off, the order for the ADI-2 was placed.

The sound: w/ K1000

As mentioned above, I found this little thing jawdropping right off the bat. (Well, not right off the bat. When I first saw it I thought "my isn't that ugly.") I listened and listened and couldn't stop. Album after album had a quality that was nearly indescribable that made me want to listen more. I know you all want to know exactly what the differences between this and the Bel Canto or Indigo were, but the closest I can come is that this sounds much more "real." This is a product of increased detail, non-rolled off treble (which it now sounds like the indigo suffers from) and outstanding soundstaging (something I had doubts about a source mattering in). A few times I had been surprised on some albums with a sound that seemed to be real while using the K1000s, but this was a rare occurence. Now, this happens over and over again, and I love it.

The sound: ER-4S out of built-in amp

The built-in amp is actually surprisingly good, I find, at least with the etys. I have always been skeptical about drastic differences in solid state amplifiers and still am, but I can safely say that this one in particular does its job quite well in terms of giving the etys some much needed kick. The volume pot was set at about 1/3 the way with them, so I imagine it could power some pretty inefficient headphones adequately. Unfortunately I don't have any "normal" headphones to try or "normal" headphone amps to compare to, so take my impressions in this section with a grain of salt.

Final thoughts

Hopefully I'll find the time to do something more substantial in the way of a review, but if not, this should get a bit of the word out on this device. What I'd really like to see/hear is a comparison between the Benchmark, the Apogee, and the ADI-2. I'm sure the other two would likely outclass the lowly ADI-2, but given the price difference, I'm wondering by how much... If anyone has any specific questions, let me know and I'll try to answer them as best I can.

 

[lan]

It's refreshing to see somebody go on the limb and try something new.

Glad you like it. I'd wait a week or two for burnin. Should be sweeter then. I'm a fan of the AKM sound so I'm sure I'd like this also. I wonder if this would sound like a better 0404. hmm........

What kind of power adaptor did they give you with the unit?

My only recommendations at this point is better transport, digital cable, power conditioning, new power adaptor for this unit, and modding it.

Oh yeah new interconnects also

 

[the terabyte]

Quote:

Originally Posted by lan It's refreshing to see somebody go on the limb and try something new. Glad you like it. I'd wait a week or two for burnin. Should be sweeter then. I'm a fan of the AKM sound so I'm sure I'd like this also. I wonder if this would sound like a better 0404. hmm........ What kind of power adaptor did they give you with the unit? My only recommendations at this point is better transport, digital cable, power conditioning, new power adaptor for this unit, and modding it. Oh yeah new interconnects also

They give a simple 1.25A 12V switching unit, which I'm sure can be easily bettered (although one person claimed it was good, so who knows). I'm looking for a new transport actually because the Transit drivers are horrible in OS X, but I can't find anything else near that price (I'm using a laptop). I am curious to try out a battery setup as it seems like the ultimate in power conditioning. We'll see, I suppose.

 

[lan]

Hmm just searched. It uses switching power supply.

"Following the 'Universal Power Supply' philosophy of RME's Digiface, Multiface, QuadMic und OctaMic, the ADI-2 comes with an external switching power supply. The unit's additional internal switching power supply has been specially designed and optimized for audio applications. It accepts any voltage from 7 to 30 V, be it AC or DC, and even runs on batteries and rechargeable batteries."

As always hearing is believing though. Some people would swear away from switching power supplies though.

This is an interesting unit at a good price. I have to acquire one to test maybe.

 

[Daroid]

Very intereisting, and good to hear that you like it. Can't identify the JRC NJM4580 opamp on the images, but is it socketed (DIP) or SOIC PCB mount ?
Yeah, it isn't exactly the prettiest piece of gear, but it's the inside that makes the sound in the end

 

[the terabyte]

Quote:

Originally Posted by Daroid Very intereisting, and good to hear that you like it. Can't identify the JRC NJM4580 opamp on the images, but is it socketed (DIP) or SOIC PCB mount ? Yeah, it isn't exactly the prettiest piece of gear, but it's the inside that makes the sound in the end

they aren't socketed, unfortunately. here's a large crop on which one can easily see the chips (400KB): http://www.server605.org/files/CRW_5969-2.jpg

 

[Glassman]

the socketed PDIP8 part is actually Xilinx serial EEPROM, it stores configuration bitstream, that is loaded into the Spartan FPGA upon powering on.. it's socketed so that it's possible to obtain newer firmware in the future..

interesting thing is, however, just single 25MHz oscillator.. I wonder where the audio clocks are being made, using the Spartan internal clock management functions? that wouldn't be the cleanest way.. hmm, I'm sure RME know what they are doing..

 

[byronyu]

"The DAC is the AKM4395 , the same that is found in the E-MU 0404 and AKM's top of the line (discounting the 4396 which supports DSD)."

Does that mean that discounting the power supply, the quality of which i am unaware of, this will sound basically like a modded 0404?

 

[Daroid]

Hard to say, owning neither of them. The DAC has little to do about the final sound quality output - i.e. a lot can be done; good or bad to alter the sound. For example the use of opamps, capacitors in signal path, and physical board layout. Though, I'll bet that the heart of most expensive DACs available today is the very same DAC, since 1) it sounds very neutral to most people, 2) It's the top offering from Asahi Kasei, 3) Design is tested through-out and is a safe bet since the DAC is from 2001.

 

[Daroid]

Any news ? Do you still like the ADI-2 now as much as you did when you firstly heard it, or have you grown tired of it ? Has the sound changed during use, like a "burn-in" ?

 

[the terabyte]

Quote:

Originally Posted by Daroid Any news ? Do you still like the ADI-2 now as much as you did when you firstly heard it, or have you grown tired of it ? Has the sound changed during use, like a "burn-in" ?

I will hopefully be able to find some more time this weekend to write up my thoughts in more detail, but the short of it is yes, I still like it as much as ever. I'm not sure whether or not the sound has changed, but if it has, it is for the slightly more mellow side. I've noticed better sibilance control with the K1000s (though the ER-4S still suffer from this, so it may not be the source), as well as a more prominent midrange that actually made me take notice to the drastic difference in midrange quality the ER-4S and K1000 have (I'm looking for a replacement for the etys as I decided that their midrange was horrible by comparison). Despite this mellowing out, it still has the dynamics I'm after. All of the above observations may also just be things that are only noticed through extended listening, so I can't say that "burn in" is the cause, though. I'm also looking into a replacement powersupply, to see if the fact that the included is a switching unit really makes that much of a difference (I figure that if the ADI-2 is fed a DC signal the internal switching power supply will be bypassed as theres nothing to "switch," though I may be mistaken).

 

[dmoffitt]

mmm transformer coupled coaxial SPDIF's - a lot like the EMU1212 (and, while i haven't taken it apart, i'd guess my m-audio firewire 410)

 

[Distroyed]

I hope you find someone to contrast with the Benchmark Dac 1. I found that DAC to be extremely disappointing, and would like to hear your comparision to it.

 

[the terabyte]

Quote:

Originally Posted by Distroyed I hope you find someone to contrast with the Benchmark Dac 1. I found that DAC to be extremely disappointing, and would like to hear your comparision to it.

I'm going to bring the ADI-2 back home with me while I'm on spring break next week (I'm off at college right now in the middle of nowhere) and hopefully track down a dealer with the DAC-1 and ideally Apogee Mini-DAC. The other unit that caught my eye was the Lucid DA9624, which although is a relatively old device, is still priced competitively and likely sounds damn good.

 

[the terabyte]

I just got back from a local pro audio store where I took some time to compare the Apogee Mini-DAC (w/ USB input) to the ADI-2. With both setups, I used the headphone out to my ER-4S. The ADI-2 was connected to my Transit and the Mini-DAC was connected directly with USB input.

I listened to a variety of songs (no time for full albums) and tried both the "quick switch" and "listen for a while, then switch" techniques. One cannot be completely sure that perfect volume matching was done, so take these impressions with a grain of salt. The first thing I noticed switching between them was how similar they sounded. Both were smooth, though if pressed I would say the ADI-2 was less so, though this in fact gave it a more dynamic sound. The Apogee had more of a fullness to it, but some classical works sounded slightly compressed.

The specific area where the two differentiated themselves most was in the high end. Though the Apogee didn't have the sizzle the ADI-2 had, it had more natural extension, more "air." Is the difference worth the $600 (retail) difference? I can't say. It's more of a difference than I've ever heard in cables or anything of that sort, but it's less than that between, for example, the Bel Canto and the ADI-2. The store owner offered me a deal on the Apogee that's pretty hard to refuse, so I'll likely be selling my ADI-2 and moving on to the Apogee.

As per the volume dial on the Mini-DAC, it "goes to 11" in terms of sound quality, while the ADI-2, a solid performer with more features (that I don't use), only gets to 10 in my opinion. Though it is still a great DAC in my eyes, it simply can't compete with something that costs twice as much with half the features.