- Joined
- Aug 18, 2007
- Posts
- 17,452
- Likes
- 835
This isn't gonna be like one of my previous reviews. It's a belated re-review of the Audioengine D2 DAC, which I believe I posted to Computer Audio where it didn't belong last December 2016, and it may have been moved to this forum and subsequently lost somehow. It was pointed out as missing this January, after my MacBook had a serious crash that wiped out everything new from before Xmas break thru the 12th of January, so my 1st review is gone forever.
To complicate things, I developed a much more severe case of tinnitus in my right ear after an infection (MRI normal, but definite hearing loss above 10Khz with the ringing at about 10-12KHz). So I am having to do much of this review based on memory from when I had better hearing. But I felt that I should at least post the impressions that I had when comparing the Audioengine D2 to my Airport Express, CEntrance DACmini, and my PS Audio Perfectwave DAC Mk2 (PWD) before my condition worsened.
I didn't feel right about not re-doing my review, especially since I genuinely enjoy and highly recommend the product. They are currently available on Amazon for $399 which is a great price for the sound and features it offers.
https://www.amazon.com/Audioengine-D2-Premium-24-bit-Wireless/dp/B006IPH496/
I have been very impressed with the D2 as the best wireless DAC that I have tried. My Perfectwave DAC Mk2 has the ethernet bridge to eliminate having to plug it directly into a computer or other transport, and it allows me to access my entire music library that won't fit on my MacBook or iPhone.
However, the bridge is wired and it also requires additional software like JR Music server and JR Music Player iPhone App to control it. And unfortunately the Mac OS X version of the JR Music server was crashing so much at the time that I quit using the Bridge completely as soon as I received the D2 two years ago. It's that good.
With the D2 I am able to leave the transmitter plugged into my iMac 24/7, with iTunes running as a music server, and I can use the iPhone Remote app to control my music playing through my D2 > Eddie Current ZDT amplifier whenever I want. We already leave the iMac running to serve music and movies to all our Macs and Apple TV, because with five of us in the family we can easily exceed the 1TB Comcast bandwidth limit when streaming via the cloud - so we stream everything from the iMac instead.
We never use the iMac for anything that requires the built-in speakers, so we leave the output set for the USB with the D2 DAC. I have a VNC app on my iPhone 7+ and iPad Air, in case someone does switch the iMac output to the internal speakers and I need to remotely switch it back to use the D2 for audio.
The Audioengine D2 is a 2-piece wireless DAC which has a separate transmitter and receiver that work on their own 2.4Ghz WiFi channel, but doesn't require a WiFi network to communicate. The audio is transmitted losslessly at up to 24/96 bit rates. The transmitter can be powered by USB, or by the 6V power brick that ships with it. My son told me the iPhone camera connection kit isn't powerful enough to run the transmitter's USB section, even when the D2 is plugged into it's power brick that apparently only powers the transmitter radio. The SPDIF receiver/DAC section is powered by the 6V 1000ma power brick only.
The Transmitter has USB audio and optical SPDIF inputs, so it can also be used with a standalone CD/DVD/BD player or HDTV that has an optical output. And the receiver has a optical output and analog RCA analog output, with decoding done by an internal AK4396 DAC (if I recall correctly, which when properly implemented can result in excellent sound).
The D2 can also be used solely as a USB to SPDIF converter, or as an optical SPDIF wireless transmitter, yet it also includes a nice DAC in case you don't have another DAC to use with it. This is similar to how we previously used our several Apple Airport Express units, which I also compared to the D2 DAC for feeding optical into my Perfectwave DAC Mk2.
The transmitter also has an output level control, so that if you are sitting at the source and playing through a remote amplifier across the room/house you can control the volume at the source without getting up. Both units have a "power" button and a "pair" button, and you can have multiple units in the house working with different sources and amplifiers, depending on how you pair them. They are small and about the size of 2-3 stacked CD cases each.
(1) My first comparison of the D2 was vs my CEntrance DACmini that I use in the bedroom daily with my MacBook Pro. The DACmini previously beat out my old PS Audio Digital Link III, as well as my well respected Stello DA100 and Apogee MiniDAC. I parted with the previous DACs because the CEntrance seemed to offer the micro-detail of the Apogee, plus the refinement and larger soundstage of the Stello, but without the jitter of the Digital Link III when used with some lesser transports (like 1st Gen Airport Express and 1st Gen Apple TV).
In this comparison of the D2 vs the well known DACmini, I tested each as a DAC-only, with USB and optical sources, feeding their RCA outputs (with ALO Audio SXT cables) into my Edie Current ZDT amplifier, as well as using the DACmini's built-in amplifier. And I used a variety of headphones, including Sennheiser HD600 and HD800, HiFiman HE-560 and Edition X, Grado HF-2, and Audeze LCD-2 V2.
Note regarding synergy of the gear tested - the ZDT amplifier pairs much better than the DACmini with the HD800 and Grado HF-2 headphones, making the choice of DAC less important when using this amp with those phones. It was actually harder to tell the difference between DACs when using the ZDT amp, while the DACmini's amp was less forgiving with different DACs and headphones, and could become a little more edgy with certain music played through these two headphones. So, remember that your amp and headphone choices can definitely affect how much you enjoy the D2 DAC.
Regardless, with my MacBook Pro via USB or optical output, the Audioengine D2's RCA output was basically almost indistinguishable from my $800 DACmini DAC in most areas, including excellent frequency response, extension, speed, micro-detail, ambience, air, and space. The sound is quite neutral with little flavor of it's own, just like the DACmini,
I would not call either DAC overly analytical or sterile, although neither one is particularly smooth and warm either - just neutral, crisp and detailed. While I can't get into the detailed descriptions of the DAC + Amp + phones with specific songs, this far out from the worsening of my tinnitus after my first review, I do vividly recall how closely these two DACs performed side by side.
So, if you've heard the DACmini for yourself then you have a better idea of how this DAC might also sound. If you thought that the DACmini was too bright (unless used with a warm amp), then this might not be the DAC for you either.
Nevertheless, while quite open and transparent sounding, in some instances (especially with the DACmini's built-in amp) I thought the DACmini's DAC was slightly less analytical than the D2, although neither one was as warm, smooth, and romantic sounding as my old Stello DA100 or my current Perfectwave DAC (PWD). This was the same result whether feeding the D2 RCA or optical outputs into the DACmini (to use its amplifier), although less so when feeding them into the ZDT amp which was more forgiving as noted below.
(2) Switching these two DACs to directly feed my Eddie Current ZDT amplifier (using ALO Audio SXT RCA cables) improved the sound noticeably, with more bass impact and warmth, giving the instruments more body and presence. Ambience and Imaging were surprisingly good using these two DACs via the DACmini amp, but they improved even more with the ZDT amplifier. Basically the D2 scales up when you upgrade your amplifier ($3,000 maxed out ZDT). There is very good synergy using both of these DACs with my ZDT amplifier, and as noted before, the differences in the D2 and DACmini as a DAC-only are smaller with a better amp like the ZDT.
(3) As I only had one set of the ALO Audio SXT RCA cables and I wanted to do some A/B testing, I tried each DAC with these, as well as using a pair of Anti-Cables RCA interconnects. I performed an A/B comparison with one DAC connected to the ZDT's input #1 and the other DAC on input #2. The differences the cables made was negligible on the sound differences between the two DACs, and my impressions remained the same.
(4) And as I mentioned, I'm currently using the D2 paired directly with my ZDT amplifier, bypassing my Perfectwave DAC altogether unless I'm sitting on the couch with my MacBook right there to plug into the PWD. The ZDT is less picky about what DAC I use, so the D2 > ZDT is perfect to casually listen while controlling my music playback with my iPhone.
So, in my next comparison I set out to explore the quality of the D2 analog output vs my old 1st Gen Airport Express for wireless audio, while connected directly to the ZDT amp. I left the D2 receiver's analog outputs connected to the amp's RCA input #1, and added the Apple Airport Express analog output to the amp's input #2 (using my ALO Audio SXT mini-RCA interconnects).
Using Airplay to send music through the Airport Express analog output was a huge disappointment. There simply was no comparison to the excellent sound quality of the D2. The 1st Get Airport Express sounded dull and lifeless when compared the D2 analog output - with lack of sparkle, detail, extension, and soundstage.
It was worse than any Bluetooth wireless audio, and even the Audioengine B1 upsampling bluetooth DAC beats the crap out of the Airport Express (the B1 is actually quite good with my iPhone bluetooth, and may be better for those who prefer a warmer, punchier, and more euphonic or romantic sound.
(5) The next step was to test the D2 optical SPDIF output vs the Airport Express optical output. When I compared the D2 optical out vs the Airport Express optical out, feeding them into the Perfectwave DAC and then into the ZDT amp, the same differences were there. There was no doubt that Airport Express via optical out still sounded terrible in comparison to the D2, and I'm not sure it was any better than the Airport Express analog out. It's crazy how a bad optical source can make a $4,000 DAC sound bad.
Maybe the old Airport is fine for casual listening in a college student's apartment, but not by any definition would the 1st Gen Airport Express optical or analog output be close to "audiophile" quality. It's no wonder that I retired my Airport Express over 2 years ago.
I seem to recall a few years ago that the Apple TV 2nd/3rd generation optical output was much better than the optical output of the 1st Gen Airport Express or ATV, so I have to wonder if the 2nd Gen Airport Express is also better. Maybe I'll pick up a newer one to test it one of these days - it's too bad the 4th Gen ATV lost the optical output, because I do have one of those.
(6) And lastly, I compared the the Audioengine D2's RCA output to the it's own optical out. The D2's RCA and optical outputs operate simultaneously, making it easier to compare them. I connected the D2 RCA out to my ZDT amplifier input #1, and connected the Perfectwave DAC Mk2 RCA output to the amp's input #2. In this case I then connected the D2 optical out into the Perfectwave DAC, so that I could compare the D2 analog output directly vs the D2 optical output that was feeding a better DAC.
When switching between the ZDT input #1 and #2 (which was the D2 analog vs D2 optical) the sound was basically indistinguishable between inputs. I simply couldn't tell which input I was listening to, and the sound signature and quality of the RCA out and optical out were nearly identical, despite using the optical with the PWD. I don't know if the D2 optical out is limited by the design to sound the same as it's RCA output, but using the D2 optical into the PWD didn't result in any improvement over the already excellent sound out of the RCA jacks.
It was only when connecting my DVD player or Macbook Pro directly to the perfect wave DAC, via coax or optical with the same music, that I could hear a difference with the PWD. With the MacBook USB > PWD > ZDT having a little more air and ambience and depth of stage, and slightly fuller impact and weight to the instruments, one could again appreciate the more expensive DAC.
SUMMARY: The Audioengine D2 is a very nice sounding low to mid-level wireless DAC that rivals a wired DAC costing twice a much (albeit without a built-in amp). The RCA output is clean and crisp, and neutral or uncolored sounding, making most audiophiles content with the sound, especially vs using an Airport Express with Airplay. And if you want a slightly warmer sounding wireless DAC, with slightly less micro-detail and ambience, but more impact, punch, and warmth, then consider the Audioengine B1 wireless DAC with 24/96 upsampling. That is what I have connected to my ZDT amp's input #3 right now.
Based on what I heard, the main reason that I see to use the D2 optical output is when you want to listen to music wirelessly but your home theater receiver or headphone amp is out of available analog inputs. Otherwise you'll get a similar performance out the D2 RCA output, and can skip the step of having an extra DAC in the music's pathway.
Right now I have the D2 RCA output connected directly to one of the inputs on my ZDT amp, and I often I don't bother turning on the PWD for a quick listen that the D2 can handle nicely on its own. When I want the ultimate listening experience, then I'll use my MacBook Pro via the PWD USB or optical, or I use my CD player on the PWD coax input. I still use the B1 bluetooth DAC on input #3 with my iPhone or iPad which can't work with the D2.
I may someday go back to using the PWD ethernet bridge, but with the B1 and D2 I can can have 90% of the sound quality and control my music easily with my iPhone, without the trouble of upgrading my buggy JR Music player or buying some other DLNA/uPNP music controller to fetch music from my NAS and send it to the PWD via ethernet cable. I don't even have my PWD connected to ethernet anymore, after getting these wireless DACs.
The D2 comes with the transmitter and receiver, two power bricks, a USB cable, and a set of RCA cables, so you can get started using it right away.
I want to thank Brady and Brett at Audiengine for the use of the D2 DAC, and apologize for taking so long to repost my review after it was lost.
To complicate things, I developed a much more severe case of tinnitus in my right ear after an infection (MRI normal, but definite hearing loss above 10Khz with the ringing at about 10-12KHz). So I am having to do much of this review based on memory from when I had better hearing. But I felt that I should at least post the impressions that I had when comparing the Audioengine D2 to my Airport Express, CEntrance DACmini, and my PS Audio Perfectwave DAC Mk2 (PWD) before my condition worsened.
I didn't feel right about not re-doing my review, especially since I genuinely enjoy and highly recommend the product. They are currently available on Amazon for $399 which is a great price for the sound and features it offers.
https://www.amazon.com/Audioengine-D2-Premium-24-bit-Wireless/dp/B006IPH496/
I have been very impressed with the D2 as the best wireless DAC that I have tried. My Perfectwave DAC Mk2 has the ethernet bridge to eliminate having to plug it directly into a computer or other transport, and it allows me to access my entire music library that won't fit on my MacBook or iPhone.
However, the bridge is wired and it also requires additional software like JR Music server and JR Music Player iPhone App to control it. And unfortunately the Mac OS X version of the JR Music server was crashing so much at the time that I quit using the Bridge completely as soon as I received the D2 two years ago. It's that good.
With the D2 I am able to leave the transmitter plugged into my iMac 24/7, with iTunes running as a music server, and I can use the iPhone Remote app to control my music playing through my D2 > Eddie Current ZDT amplifier whenever I want. We already leave the iMac running to serve music and movies to all our Macs and Apple TV, because with five of us in the family we can easily exceed the 1TB Comcast bandwidth limit when streaming via the cloud - so we stream everything from the iMac instead.
We never use the iMac for anything that requires the built-in speakers, so we leave the output set for the USB with the D2 DAC. I have a VNC app on my iPhone 7+ and iPad Air, in case someone does switch the iMac output to the internal speakers and I need to remotely switch it back to use the D2 for audio.
The Audioengine D2 is a 2-piece wireless DAC which has a separate transmitter and receiver that work on their own 2.4Ghz WiFi channel, but doesn't require a WiFi network to communicate. The audio is transmitted losslessly at up to 24/96 bit rates. The transmitter can be powered by USB, or by the 6V power brick that ships with it. My son told me the iPhone camera connection kit isn't powerful enough to run the transmitter's USB section, even when the D2 is plugged into it's power brick that apparently only powers the transmitter radio. The SPDIF receiver/DAC section is powered by the 6V 1000ma power brick only.
The Transmitter has USB audio and optical SPDIF inputs, so it can also be used with a standalone CD/DVD/BD player or HDTV that has an optical output. And the receiver has a optical output and analog RCA analog output, with decoding done by an internal AK4396 DAC (if I recall correctly, which when properly implemented can result in excellent sound).
The D2 can also be used solely as a USB to SPDIF converter, or as an optical SPDIF wireless transmitter, yet it also includes a nice DAC in case you don't have another DAC to use with it. This is similar to how we previously used our several Apple Airport Express units, which I also compared to the D2 DAC for feeding optical into my Perfectwave DAC Mk2.
The transmitter also has an output level control, so that if you are sitting at the source and playing through a remote amplifier across the room/house you can control the volume at the source without getting up. Both units have a "power" button and a "pair" button, and you can have multiple units in the house working with different sources and amplifiers, depending on how you pair them. They are small and about the size of 2-3 stacked CD cases each.
(1) My first comparison of the D2 was vs my CEntrance DACmini that I use in the bedroom daily with my MacBook Pro. The DACmini previously beat out my old PS Audio Digital Link III, as well as my well respected Stello DA100 and Apogee MiniDAC. I parted with the previous DACs because the CEntrance seemed to offer the micro-detail of the Apogee, plus the refinement and larger soundstage of the Stello, but without the jitter of the Digital Link III when used with some lesser transports (like 1st Gen Airport Express and 1st Gen Apple TV).
In this comparison of the D2 vs the well known DACmini, I tested each as a DAC-only, with USB and optical sources, feeding their RCA outputs (with ALO Audio SXT cables) into my Edie Current ZDT amplifier, as well as using the DACmini's built-in amplifier. And I used a variety of headphones, including Sennheiser HD600 and HD800, HiFiman HE-560 and Edition X, Grado HF-2, and Audeze LCD-2 V2.
Note regarding synergy of the gear tested - the ZDT amplifier pairs much better than the DACmini with the HD800 and Grado HF-2 headphones, making the choice of DAC less important when using this amp with those phones. It was actually harder to tell the difference between DACs when using the ZDT amp, while the DACmini's amp was less forgiving with different DACs and headphones, and could become a little more edgy with certain music played through these two headphones. So, remember that your amp and headphone choices can definitely affect how much you enjoy the D2 DAC.
Regardless, with my MacBook Pro via USB or optical output, the Audioengine D2's RCA output was basically almost indistinguishable from my $800 DACmini DAC in most areas, including excellent frequency response, extension, speed, micro-detail, ambience, air, and space. The sound is quite neutral with little flavor of it's own, just like the DACmini,
I would not call either DAC overly analytical or sterile, although neither one is particularly smooth and warm either - just neutral, crisp and detailed. While I can't get into the detailed descriptions of the DAC + Amp + phones with specific songs, this far out from the worsening of my tinnitus after my first review, I do vividly recall how closely these two DACs performed side by side.
So, if you've heard the DACmini for yourself then you have a better idea of how this DAC might also sound. If you thought that the DACmini was too bright (unless used with a warm amp), then this might not be the DAC for you either.
Nevertheless, while quite open and transparent sounding, in some instances (especially with the DACmini's built-in amp) I thought the DACmini's DAC was slightly less analytical than the D2, although neither one was as warm, smooth, and romantic sounding as my old Stello DA100 or my current Perfectwave DAC (PWD). This was the same result whether feeding the D2 RCA or optical outputs into the DACmini (to use its amplifier), although less so when feeding them into the ZDT amp which was more forgiving as noted below.
(2) Switching these two DACs to directly feed my Eddie Current ZDT amplifier (using ALO Audio SXT RCA cables) improved the sound noticeably, with more bass impact and warmth, giving the instruments more body and presence. Ambience and Imaging were surprisingly good using these two DACs via the DACmini amp, but they improved even more with the ZDT amplifier. Basically the D2 scales up when you upgrade your amplifier ($3,000 maxed out ZDT). There is very good synergy using both of these DACs with my ZDT amplifier, and as noted before, the differences in the D2 and DACmini as a DAC-only are smaller with a better amp like the ZDT.
(3) As I only had one set of the ALO Audio SXT RCA cables and I wanted to do some A/B testing, I tried each DAC with these, as well as using a pair of Anti-Cables RCA interconnects. I performed an A/B comparison with one DAC connected to the ZDT's input #1 and the other DAC on input #2. The differences the cables made was negligible on the sound differences between the two DACs, and my impressions remained the same.
(4) And as I mentioned, I'm currently using the D2 paired directly with my ZDT amplifier, bypassing my Perfectwave DAC altogether unless I'm sitting on the couch with my MacBook right there to plug into the PWD. The ZDT is less picky about what DAC I use, so the D2 > ZDT is perfect to casually listen while controlling my music playback with my iPhone.
So, in my next comparison I set out to explore the quality of the D2 analog output vs my old 1st Gen Airport Express for wireless audio, while connected directly to the ZDT amp. I left the D2 receiver's analog outputs connected to the amp's RCA input #1, and added the Apple Airport Express analog output to the amp's input #2 (using my ALO Audio SXT mini-RCA interconnects).
Using Airplay to send music through the Airport Express analog output was a huge disappointment. There simply was no comparison to the excellent sound quality of the D2. The 1st Get Airport Express sounded dull and lifeless when compared the D2 analog output - with lack of sparkle, detail, extension, and soundstage.
It was worse than any Bluetooth wireless audio, and even the Audioengine B1 upsampling bluetooth DAC beats the crap out of the Airport Express (the B1 is actually quite good with my iPhone bluetooth, and may be better for those who prefer a warmer, punchier, and more euphonic or romantic sound.
(5) The next step was to test the D2 optical SPDIF output vs the Airport Express optical output. When I compared the D2 optical out vs the Airport Express optical out, feeding them into the Perfectwave DAC and then into the ZDT amp, the same differences were there. There was no doubt that Airport Express via optical out still sounded terrible in comparison to the D2, and I'm not sure it was any better than the Airport Express analog out. It's crazy how a bad optical source can make a $4,000 DAC sound bad.
Maybe the old Airport is fine for casual listening in a college student's apartment, but not by any definition would the 1st Gen Airport Express optical or analog output be close to "audiophile" quality. It's no wonder that I retired my Airport Express over 2 years ago.
I seem to recall a few years ago that the Apple TV 2nd/3rd generation optical output was much better than the optical output of the 1st Gen Airport Express or ATV, so I have to wonder if the 2nd Gen Airport Express is also better. Maybe I'll pick up a newer one to test it one of these days - it's too bad the 4th Gen ATV lost the optical output, because I do have one of those.
(6) And lastly, I compared the the Audioengine D2's RCA output to the it's own optical out. The D2's RCA and optical outputs operate simultaneously, making it easier to compare them. I connected the D2 RCA out to my ZDT amplifier input #1, and connected the Perfectwave DAC Mk2 RCA output to the amp's input #2. In this case I then connected the D2 optical out into the Perfectwave DAC, so that I could compare the D2 analog output directly vs the D2 optical output that was feeding a better DAC.
When switching between the ZDT input #1 and #2 (which was the D2 analog vs D2 optical) the sound was basically indistinguishable between inputs. I simply couldn't tell which input I was listening to, and the sound signature and quality of the RCA out and optical out were nearly identical, despite using the optical with the PWD. I don't know if the D2 optical out is limited by the design to sound the same as it's RCA output, but using the D2 optical into the PWD didn't result in any improvement over the already excellent sound out of the RCA jacks.
It was only when connecting my DVD player or Macbook Pro directly to the perfect wave DAC, via coax or optical with the same music, that I could hear a difference with the PWD. With the MacBook USB > PWD > ZDT having a little more air and ambience and depth of stage, and slightly fuller impact and weight to the instruments, one could again appreciate the more expensive DAC.
SUMMARY: The Audioengine D2 is a very nice sounding low to mid-level wireless DAC that rivals a wired DAC costing twice a much (albeit without a built-in amp). The RCA output is clean and crisp, and neutral or uncolored sounding, making most audiophiles content with the sound, especially vs using an Airport Express with Airplay. And if you want a slightly warmer sounding wireless DAC, with slightly less micro-detail and ambience, but more impact, punch, and warmth, then consider the Audioengine B1 wireless DAC with 24/96 upsampling. That is what I have connected to my ZDT amp's input #3 right now.
Based on what I heard, the main reason that I see to use the D2 optical output is when you want to listen to music wirelessly but your home theater receiver or headphone amp is out of available analog inputs. Otherwise you'll get a similar performance out the D2 RCA output, and can skip the step of having an extra DAC in the music's pathway.
Right now I have the D2 RCA output connected directly to one of the inputs on my ZDT amp, and I often I don't bother turning on the PWD for a quick listen that the D2 can handle nicely on its own. When I want the ultimate listening experience, then I'll use my MacBook Pro via the PWD USB or optical, or I use my CD player on the PWD coax input. I still use the B1 bluetooth DAC on input #3 with my iPhone or iPad which can't work with the D2.
I may someday go back to using the PWD ethernet bridge, but with the B1 and D2 I can can have 90% of the sound quality and control my music easily with my iPhone, without the trouble of upgrading my buggy JR Music player or buying some other DLNA/uPNP music controller to fetch music from my NAS and send it to the PWD via ethernet cable. I don't even have my PWD connected to ethernet anymore, after getting these wireless DACs.
The D2 comes with the transmitter and receiver, two power bricks, a USB cable, and a set of RCA cables, so you can get started using it right away.
I want to thank Brady and Brett at Audiengine for the use of the D2 DAC, and apologize for taking so long to repost my review after it was lost.
