slim.a
1000+ Head-Fier
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Update 06 july 09
I decided to update my review to post my impressions after a few optimizations/upgrades I made to my system.
The DAC-100 is basically the DAC section of the Audio-GD Compass.
The ST-3 is a sigle ended Class A headphone amp which should be comparable to the Audio-GD Compass amp section according to Kingwa.
Part I : Initial review (including a comparison with EMU 0404 USB, Zero DAC and Little Dot MKIII)
Part II: Optimization of the system
Part III : Comparison with Audio-GD DAC19 MK3 (review here)
Part I : Initial review (January 09)
Hello,
I saw from the 'Designing an alternative to the Zero DAC/amp -- Now it has a name: The Audio-gd Compass' thread that Audio-gd gear raised a lot of interest in this forum, so I decided to share my experience with 2 components I bought from Kingwa at Audio-GD.
While I have been a regular reader on head-fi, this is my first post so I hope it is clear enough to be understood.
System
Software :
Foobar with ASIO output
Sources :
Audio-gd DAC-100
EMU-0404 USB
ZERO DAC
Creative Audigy 2ZS Notebook
Headphone amps :
Audio-gd ST-3
Little Dot MKIII (with upgraded tubes)
Tubes used in the Little Dot MKIII:
GE Five Star 6AK5 (matched pair)
Mullard M8100 / CV4010 Mil. Spec. (Matched pair)
6H6P-I (Matched pair)
NOS JAN Sylvania 6AK5 (EF95)
Headphones :
Sennheiser HD-650 with Moon Audio Blue Dragon V3 cable
Sony MDR 300
Cables :
Kimber PBJ
Custom Canare coaxial Cable "Signature Series 77" from Cable Solutions
Belkin Coaxial cable Silver Series
Real Cable USB
Belkin Gold USB
Below is the set-up I currently use :
Dell Inspiron ---> Foobar 0.9.5.2 with ASIO plug-in ---> 'Real Cable' USB cable ---> EMU 0404 USB ---> Canare coaxial Cable "Signature Series 77" ---> Audio-GD DAC-100 ---> Kimber PBJ ---> Audio-GD ST-3 ---> Moon Audio Blue Dragon v3 ---> Senneheiser HD-650
Background
Before getting the "audiophile bug" I was quite satisfied with a simple set-up consisting of Creative 2ZS Notebook and cheap Sony MDR 300.
Then I bought an EMU-0404 USB and shortly after a pair of Sennheiser HD-650 and I wad quite happy for a while. Indeed, the HD-650 are among the top rated headphones and the EMU 0404 USB had superb measured performance (113db of SNR and Dynamic range using RMAA). However, I had a growing feeling that I wasn't getting enough from the HD-650 and the sound was too thin to my taste.
Then I decided to buy a Little Dot MKIII which was a huge shock for me! While the specs were nowhere near those of the 0404 USB, the sound I got from was much better: the bass was stronger, there was more detail, the sound more rich and overall it was much more enjoyable. That led me to understand that the specs do not tell you the whole story. Then I stumbled on the Zero DAC review on the Head-Fi Forum which led me to buying it. Then I read in the thread that the OP-amps made by a lot of improvement to the stock Zero DAC which got me curious about the company which seemed to have a lot of in the head-fi forum.
When the left channel from my Zero DAC started making some audible noise, I decided to try and buy a better built DAC. The pictures and the description of the DAC-100 impressed me a lot (compared to the price) and I placed an order with Kingwa who has always very responsive with my e-mails.
DAC-100 (with OPA-Earth)
First impressions :
First, the build quality of DAC-100 is very impressive compared to that of the Zero DAC. Also the DAC-100 is dead silent.
Before burn-in, the DAC-100 is very soft sounding, it also lacks a little bit of resolution in comparison to the EMU 0404 USB, but I liked it from the start and enjoyed the sound very much.
While I didn't do any critical listening during the first week I owned the unit, I feel that it takes at least around 150 hours of burn-in to reach its full potential.
Burn-in :
The DAC-100 is a truly impressive DAC : It combines the transparency of the 0404 USB and the smoothness of the Zero DAC.
It is a very transparent piece of gear, it is very detailed (more than 0404 USB which has got many positive reviews), it has very solid bass and a very well defined soundstage. When I replaced the OPA-Earth with OPA-627 the sound became flatter, had less life and the soundstage shrunk.
SPDIF vs. USB:
The DAC-100 has two inputs: Coax and USB. While the USB input is very good (PCM2707), it only accepts 16/44 and 16/48. Therefore, when I used the EMU 0404 USB as a transport with upsampling at 24/96 with SRC, I found that the sound was warmer (more analog like) and that the soundstage improved. The sound through USB is a little bit thinner and brighter. But the difference is small and I wouldn't have noticed if I hadn't done some AB comparisons with the EMU-0404 USB. The differences may come from the drivers (custom drivers for the EMU vs. ASIO4ALL for the PCM2707) or from the quality of the USB receivers. Upsampling helps also a little bit but I still prefer the sound from the EMU with ASIO at 24/44 than the sound from USB input of the DAC-100.
However, even though the DIR9001(coax in) is supposed to reduced jitter I found that digital cables did matter and found differences between the two digital cables I have. While the Canare have a more natural sound, the Belkin, has a wider soundstage. Usually I listen to the Canare Coax.
Measurements :
I did some measurement using RMAA and EMU 0404 USB. Since I couldn't measure the DAC-100 through its SPDIF input, I only did measurement through the USB input which is limited to 16/48. The measurement were at the limit of the 16 bit test 98db SNR which indicates that the performance using 24bit data through the SPDIF would probably yield better results.
ST-3
First impressions:
After I was impressed with the DAC-100, I got curious about the ST-3 which is a Class-A Single Ended head-phone amp. I ordered the ST-3 because I was feeling the my Little Dot MKIII was maybe the weakest link in my chain.
When I received, the ST-3 I let it cook for around 40 hours before trying it. What I found got me disappointed at first. While I found that it had a great and detailed midrange, I felt that the highs were muted. The highs were much softer than those of the tubed Little Dot MKIII which was very surprising and unexpected.
I wrote a mail complaining about the sound to Kingwa. He answered very quickly and offered to take back the amp and return me the money or selling me the C2C. He also gave me advice about replacing the power cord and giving it a 100 more hours of burn-in.
So I changed the power cords of both the DAC-100 (with an Olflex power cord) and that of the ST-3 (with pure OFC power cord), plugged both units in a separate mains block away from the other equipment and let it burn-in 100 more hours without listnening to it.
Burn-in:
After around 150 hours of burn-in, I finally gave it a listen and I got a truly great sonic experience. Now, I could clearly feel that the ST-3 was miles ahead of the Little Dot MKIII (which is not a bad amp).
After around 300 hours, the sound improved to levels I have never achieved before. While I am not sure, I think that it took more than a month before the unit achieved its full potential.
Now, when I compare the unit to the Little Dot MKIII, it is like comparing a low quality Divx to a High Definition Blu-Ray. The difference is huge and you don't need to concentrate to notice differences.
Measurements:
I did some measurements doing using RMAA and found out that the SNR of the ST-3 was 104 db as indicated in audio gd site, which explains why I don't hear any hiss or noise using my Sennheiser HD-650. However when I use some low impedance ear-buds, I can hear some noise when no music is playing and the volume is turned to the maximum. But I am not sure it is relevant since it would either blow up the ear-buds or the ears at that volume.
Review of the DAC-100 & ST-3
Dynamics :
The noise floor is very low : you don't hear anything when turning the volume pot at maximum when using the Sennheiser hd-650.
The dynamics are huge, the system (Dac-100 and ST-3) can let you hear very small details. Listening, at the 'Jazz at the Pawnshop album' you can still the hear and feel the ambiance of the room even when the music is playing very loud. The dynamics are evenly spread throughout the spectrum and it feels natural.
Before listening to "The Battle" track from the Gladiator soundtrack with the DAC-100 & ST-3 combo, I always thought it was lifeless and compressed. When I listened to it with the combo, it was like a revelation : I got a truly dynamic and lifelike representation with my Sennheiser HD-650.
Transparency :
The combo is very transparent. Now, I can easily hear any change in the media player (Windows Media Player, Foobar with ASIO or Directsound), power cords, interconnects, digital cables and even USB cables ! In fact, I have found it very difficult to asses how good the ST-3 performs because any change transforms the sound of the combo (DAC-100).
Also, I can notice the difference between a lossless encoded file and an MP3. In order to confirm it and to check if it wasn't just a placebo effect, I did some ABX testing between a Wav file and 128kbps, 192kbps and 320kbps MP3s. I was able to easily hear the differences between the PCM and lower bitrates MP3s (128 and 192) and I got it right 100% just by focusing on the voices of the singers (Beegees). For the 320kbps, I got it right 7/10. But still, I feel that on long-term listening, FLAC or other lossless encoding offer a more relaxed and enjoyable sound than 320kbps.
Timbre :
The balance of the sound coming from the DAC-100 is very dependant on the OPA installed on it. The only OPA I tried are OPA-627, LM4562 and OPA-Earth. I didn't need to listen long to understand that the OPA-Earth was the clear winner, it has the most natural and dynamic sound of the 3. OPA-627 came second and LM4562 came last. I didn't try OPA 2134 because my unit was shipped with the Earth installed in it.
The timbre of the sound coming from the ST-3 is really outstanding. While you can easily get distracted in other gear by the boomy bass or the analytical highs, the ST-3 gives a sound that is balanced throughout the spectrum. In fact it seems to me that the ST-3 has a great midrange that extends in a natural and continuous way to the highs and low frequencies. While I used to think that the headphone output of the 0404 USB was very detailed in the highs because it was supposed to be transparent, I came to understand that I was hear a lot of distrotion.
In fact, I have to disagree with Kingwa on one point here. Once you give the ST-3 enough burn-in (at least 300 hours), the sound you get is nothing like tube-like but it doesn't have the digital harshness of the solid state gear I tried. The sound is very fast, clean and accurate while remaining very natural and very pleasing to listen to.
Soundstage :
The soundstage given by the system is huge and at the same time very focused.
Compared to the soundstage of the tubed Little Dot MKIII which is its major strength in my opinion, the soundstage of the ST-3 is almost as big but it is a lot more focused. The soundstage of the Little Dot seems a little fuzzy in comparison.
Also, the soundstage changes dramatically from one album to another and even from one track to another. For example, on Norah Jones 'Come away with me' album, you clearly hear differences between the tracks.
Note about the Moon Audio Blue Dragon cable :
All my review was done using the Moon Audio Blue Dragon V3 cable for my Sennheiser HD-650. When I tried the stock cable last out of curiosity, I found out that much of the characteristics described above (clean, fast, accurate, great midrange, highs and bass) are much more apparent with the Blue Dragon Cable. Through the Moon Audio Cable, the sound is cleaner (less distortion) and faster, the frequency extremities are more extended and the "veil" is lifted. If I hadn't listened to the cable I would have never been able to notice the deficiencies of the stock cable but now that I have, I can never go back.
Final thoughts
To sum-up I am very satisfied with sound using the DAC-100 and the ST-3. The sound is natural, fast, clean and transparent.
In fact it is so transparent that it was hard for me to review the gear. Each change in the interconnect affected the sound, so my review is probably biased by the quality of the cables I use, the Kimber PBJ and Canare Coaxial cable that were recommended a few years ago by Stereophile.
I have also to note that it takes a very long time break-in the Audio-gd gear.
But one thing is sure, I enjoy the sound of my system very much and I don't leave my headphones anymore either to listen to music or to watch movies.
Edit --- Comparison between the Compass and DAC-100 & ST-3 combo :
Since I haven't reviewed the Compass, I have to rely on Kingwa impressions.
According to him, the DAC section of the Compass should on par with the DAC-100 since they use the same components : AD1852, DIR9001, Nover capacitors ...
Also according to Kingwa, the amp section of the Compass is less coloured than the ST-3. It is supposed to be closer in sound character to the C2C than it is to the ST-3.
Part II: Optimization of the System
Well It has been around 6 months since my last review and I wanted to make an update to my review to share my experience with the DAC-100 paired with the ST-3 headphone amp.
My new Setup :
Foobar 0.8.3 (Otachan ASIO) ---> Wireworld ultraviolet USB ---> EMU 0404 USB ---> Hifi-Cables Sobek ---> Audio-gd DAC-100 ---> Hifi-Cables Khnoum ---> Audio-gd ST-3 ---> Moon Audio Blue Dragon v3 ---> Senneheiser HD-650
Power related Cables & Accessories : Hifi-Cables PowerTransPlus x2; Supra Mains multiplier; Essential Audio Tools Noise Eater (Parallel filter)
Other accessories : Vibapod cones, Vibrapod Isolators, plywood shelves, fiber carbon rigid sheets.
When I did my initial review in January I was unsure about how the ST-3 and DAC-100 really sound because of the limitations of the interconnects I was using at that time. Each time I changed interconnects I noticed improvements in some aspects but also drawbacks on other aspects.
Since January, I updated all my interconnects from Hifi-Cables a high-end French boutique that lets you borrow cables to try them for week before making your decision. And now, I don't feel anymore that interconnects are a limiting factor in my system (In fact, I am using a power cords that costs more than the ST-3)
So what were the changes to the sound ?
Well, the system improved in transparency, dynamics, soundstage and separation of instruments.
Transparency:
With the upgrades, I realized that the ST3/DAC100 combo was much more transparent than I first thought.
For example, when listening to the Pulse test track (which is recorded at a very low level) a lot of details become more easily apparent. Overall, it is like if I had lifted a few layers of cotton between my headphones and my ears.
I also found that I can "increase" the transparency even more by changing the Earth op-amp with the LME49720HA (a higher end version of the LM4562 that comes in metal can version). However I found that this op-amp is too revealing and a little more lightweight than the Earth op-amp. I guess that if I were doing monitoring work, it would be the opamp I will use since you can pick-up details easier than with the Earth Op-amp. I think that the AD1852 DAC used as a converter has a bit of digital sound that is masked through Earth HDAM.
Soundstage:
After the upgrades, I felt that the soundstage was not only bigger but also more focused at the same time. The soundstage extends well beyond my head with the Sennheiser HD-650 and on some recordings, there is a spooky 3D effect where you hear the instrument but also feel the person playing the instrument.
Also, when I listen to classical music, I don't feel anymore that there is a muddy mass playing. For instance, I can hear on most recording that distinct violins are playing on the left on loud passages while I used to hear sort of a one violin playing louder in intense passages.
Dynamics:
The dynamics also improved. While with my previous set-up I used to think that my system has nice dynamics, it made me aware that the Sennheiser are hard to drive. In contrast, now, I feel like the sennheiser hd-650 are some low impedance / high sensitivity headphones that can be driven pretty easily.
However, since I haven't listened to other headphone amps (such as DV337, audio-gd C2C, Lehmann Cube Linear, ...) I am pretty sure that there is still room for improvement on the dynamics side.
Notes about Media Players and Upsampling:
Before all those updates (interconnects, power conditioning, vibrapods, plywood and carbon fiber platforms ...) I used to prefer the sound with foobar 0.9.x with SRC upsampling. However, I realized now that while the upsampling brings some improvements (soundstage coherency, less digital sound, sweeter sound overall), it also lowers the transparency of the system. I feel like some small details are lost (or less apparent) with upsampling and that a kind of blanket is put between the system and me.
Finally I found that Foobar 0.8.3 (with Otachan ASIO) works best in my system. The next best player in my system is Media Monkey but I find it a little bit too much "hifi" for my taste.
Conclusion for Part II :
I have been enjoying a lot my system and I have been listening a lot more than before to music (especially classical music) so even after a few months, I am still happy with my purchase
But are there any "weaknesses" to the system ?
After a few months owning the DAC100/ST3 combo, I realized that the DAC100 (which is the DAC section of the COMPASS) has a little bit of digital sound. On live recordings, I feel like some instruments such as violins, or pianos do not sound as natural as on the real life.
This observation was further confirmed by reviews of people who own both a compass and a higher end DAC (such as DAC 19 MK3 or 19 SE). I guess that the AD1852 has some limitations in comparison to "better" DACs such as paralleled PCM1704-UK that you can find on the DAC-19MK3 or the Reference One.
Or maybe, I might be hearing he effect of jitter : the DAC-100 sounds better through its spdif input using the EMU 0404 usb as a transport. Also, I read in Stereophile that Multibit DACs (such as PCM1704 used in the DAC-19 MK3) have lower jitter than 1-bit DACs (such as the AD1852 used in the DAC100/DAC200/Compass). (Stereophile: Jitter & the Digital Interface)
Anyway, this has led me to a quest for a new DAC and I ordered a few days ago the DAC-19 MK3 from Kingwa.
The other (relative) weakness I found is that the DAC-100 / ST-3 (withe the ST-3 being the most sensitive) need really good power cords to sound their best. Those power cords usually come at a high price : I tried some entry-level power cords such as Olflex, Supra and a silver plated power cord (bought from ebay) but none of them come close to the Hifi-Cables PowerTransPlus.
Those weaknesses are only relative ones because even with a basic setup, the DAC-100 / ST-3 clearly outperform the other gear I have on hand (EMU 0404 USB, Zero DAC, Little dot MKIII, ...)
To sump up
Even if I am going to be shortly upgrading my DAC (case of upgraditis), I feel that I have reached a point where I have a very enjoyable music system. Even my non-audiophile friends tend to find my system "natural" and "lifelike". That usually was not their reaction for the few that had tried the EMU 0404 USB and Sennheiser HD-650 which did not seem to impress them nearly as much.
Also, I have been auditioning some speakers however I have been pretty disappointed : I auditioned speakers that ranged from 500€ to 5K€ that sounded bloated with low resolution.
The only system that surpassed (on most areas) the performance of my system was the JCT Heritage speakers (6moons audio reviews: JCT*Héritage AB). Those speakers made by the founder of Hifi-Cabes, act like a wide-bander : They have great resolution, soundstage and most of all you feel that highs and bass are perfectly integrated with the mids. When I listened to it, they were powered with heavily modified Atoll CD 200, stock Atoll PR300, stock Atoll AM200 and of course top of the line.
That is to say that I am quite happy with my current headphone setup and that I would need to spend a lot more to get comparable results from a speaker setup.
Part III:Comparison with Audio-GD DAC19 MK3
I have done a full length review of the DAC-19MK3 here for those who might be interested.
I decided to update my review to post my impressions after a few optimizations/upgrades I made to my system.
The DAC-100 is basically the DAC section of the Audio-GD Compass.
The ST-3 is a sigle ended Class A headphone amp which should be comparable to the Audio-GD Compass amp section according to Kingwa.
Part I : Initial review (including a comparison with EMU 0404 USB, Zero DAC and Little Dot MKIII)
Part II: Optimization of the system
Part III : Comparison with Audio-GD DAC19 MK3 (review here)
Part I : Initial review (January 09)
Hello,
I saw from the 'Designing an alternative to the Zero DAC/amp -- Now it has a name: The Audio-gd Compass' thread that Audio-gd gear raised a lot of interest in this forum, so I decided to share my experience with 2 components I bought from Kingwa at Audio-GD.
While I have been a regular reader on head-fi, this is my first post so I hope it is clear enough to be understood.
System
Software :
Foobar with ASIO output
Sources :
Audio-gd DAC-100
EMU-0404 USB
ZERO DAC
Creative Audigy 2ZS Notebook
Headphone amps :
Audio-gd ST-3
Little Dot MKIII (with upgraded tubes)
Tubes used in the Little Dot MKIII:
GE Five Star 6AK5 (matched pair)
Mullard M8100 / CV4010 Mil. Spec. (Matched pair)
6H6P-I (Matched pair)
NOS JAN Sylvania 6AK5 (EF95)
Headphones :
Sennheiser HD-650 with Moon Audio Blue Dragon V3 cable
Sony MDR 300
Cables :
Kimber PBJ
Custom Canare coaxial Cable "Signature Series 77" from Cable Solutions
Belkin Coaxial cable Silver Series
Real Cable USB
Belkin Gold USB
Below is the set-up I currently use :
Dell Inspiron ---> Foobar 0.9.5.2 with ASIO plug-in ---> 'Real Cable' USB cable ---> EMU 0404 USB ---> Canare coaxial Cable "Signature Series 77" ---> Audio-GD DAC-100 ---> Kimber PBJ ---> Audio-GD ST-3 ---> Moon Audio Blue Dragon v3 ---> Senneheiser HD-650
Background
Before getting the "audiophile bug" I was quite satisfied with a simple set-up consisting of Creative 2ZS Notebook and cheap Sony MDR 300.
Then I bought an EMU-0404 USB and shortly after a pair of Sennheiser HD-650 and I wad quite happy for a while. Indeed, the HD-650 are among the top rated headphones and the EMU 0404 USB had superb measured performance (113db of SNR and Dynamic range using RMAA). However, I had a growing feeling that I wasn't getting enough from the HD-650 and the sound was too thin to my taste.
Then I decided to buy a Little Dot MKIII which was a huge shock for me! While the specs were nowhere near those of the 0404 USB, the sound I got from was much better: the bass was stronger, there was more detail, the sound more rich and overall it was much more enjoyable. That led me to understand that the specs do not tell you the whole story. Then I stumbled on the Zero DAC review on the Head-Fi Forum which led me to buying it. Then I read in the thread that the OP-amps made by a lot of improvement to the stock Zero DAC which got me curious about the company which seemed to have a lot of in the head-fi forum.
When the left channel from my Zero DAC started making some audible noise, I decided to try and buy a better built DAC. The pictures and the description of the DAC-100 impressed me a lot (compared to the price) and I placed an order with Kingwa who has always very responsive with my e-mails.
DAC-100 (with OPA-Earth)
First impressions :
First, the build quality of DAC-100 is very impressive compared to that of the Zero DAC. Also the DAC-100 is dead silent.
Before burn-in, the DAC-100 is very soft sounding, it also lacks a little bit of resolution in comparison to the EMU 0404 USB, but I liked it from the start and enjoyed the sound very much.
While I didn't do any critical listening during the first week I owned the unit, I feel that it takes at least around 150 hours of burn-in to reach its full potential.
Burn-in :
The DAC-100 is a truly impressive DAC : It combines the transparency of the 0404 USB and the smoothness of the Zero DAC.
It is a very transparent piece of gear, it is very detailed (more than 0404 USB which has got many positive reviews), it has very solid bass and a very well defined soundstage. When I replaced the OPA-Earth with OPA-627 the sound became flatter, had less life and the soundstage shrunk.
SPDIF vs. USB:
The DAC-100 has two inputs: Coax and USB. While the USB input is very good (PCM2707), it only accepts 16/44 and 16/48. Therefore, when I used the EMU 0404 USB as a transport with upsampling at 24/96 with SRC, I found that the sound was warmer (more analog like) and that the soundstage improved. The sound through USB is a little bit thinner and brighter. But the difference is small and I wouldn't have noticed if I hadn't done some AB comparisons with the EMU-0404 USB. The differences may come from the drivers (custom drivers for the EMU vs. ASIO4ALL for the PCM2707) or from the quality of the USB receivers. Upsampling helps also a little bit but I still prefer the sound from the EMU with ASIO at 24/44 than the sound from USB input of the DAC-100.
However, even though the DIR9001(coax in) is supposed to reduced jitter I found that digital cables did matter and found differences between the two digital cables I have. While the Canare have a more natural sound, the Belkin, has a wider soundstage. Usually I listen to the Canare Coax.
Measurements :
I did some measurement using RMAA and EMU 0404 USB. Since I couldn't measure the DAC-100 through its SPDIF input, I only did measurement through the USB input which is limited to 16/48. The measurement were at the limit of the 16 bit test 98db SNR which indicates that the performance using 24bit data through the SPDIF would probably yield better results.
ST-3
First impressions:
After I was impressed with the DAC-100, I got curious about the ST-3 which is a Class-A Single Ended head-phone amp. I ordered the ST-3 because I was feeling the my Little Dot MKIII was maybe the weakest link in my chain.
When I received, the ST-3 I let it cook for around 40 hours before trying it. What I found got me disappointed at first. While I found that it had a great and detailed midrange, I felt that the highs were muted. The highs were much softer than those of the tubed Little Dot MKIII which was very surprising and unexpected.
I wrote a mail complaining about the sound to Kingwa. He answered very quickly and offered to take back the amp and return me the money or selling me the C2C. He also gave me advice about replacing the power cord and giving it a 100 more hours of burn-in.
So I changed the power cords of both the DAC-100 (with an Olflex power cord) and that of the ST-3 (with pure OFC power cord), plugged both units in a separate mains block away from the other equipment and let it burn-in 100 more hours without listnening to it.
Burn-in:
After around 150 hours of burn-in, I finally gave it a listen and I got a truly great sonic experience. Now, I could clearly feel that the ST-3 was miles ahead of the Little Dot MKIII (which is not a bad amp).
After around 300 hours, the sound improved to levels I have never achieved before. While I am not sure, I think that it took more than a month before the unit achieved its full potential.
Now, when I compare the unit to the Little Dot MKIII, it is like comparing a low quality Divx to a High Definition Blu-Ray. The difference is huge and you don't need to concentrate to notice differences.
Measurements:
I did some measurements doing using RMAA and found out that the SNR of the ST-3 was 104 db as indicated in audio gd site, which explains why I don't hear any hiss or noise using my Sennheiser HD-650. However when I use some low impedance ear-buds, I can hear some noise when no music is playing and the volume is turned to the maximum. But I am not sure it is relevant since it would either blow up the ear-buds or the ears at that volume.
Review of the DAC-100 & ST-3
Dynamics :
The noise floor is very low : you don't hear anything when turning the volume pot at maximum when using the Sennheiser hd-650.
The dynamics are huge, the system (Dac-100 and ST-3) can let you hear very small details. Listening, at the 'Jazz at the Pawnshop album' you can still the hear and feel the ambiance of the room even when the music is playing very loud. The dynamics are evenly spread throughout the spectrum and it feels natural.
Before listening to "The Battle" track from the Gladiator soundtrack with the DAC-100 & ST-3 combo, I always thought it was lifeless and compressed. When I listened to it with the combo, it was like a revelation : I got a truly dynamic and lifelike representation with my Sennheiser HD-650.
Transparency :
The combo is very transparent. Now, I can easily hear any change in the media player (Windows Media Player, Foobar with ASIO or Directsound), power cords, interconnects, digital cables and even USB cables ! In fact, I have found it very difficult to asses how good the ST-3 performs because any change transforms the sound of the combo (DAC-100).
Also, I can notice the difference between a lossless encoded file and an MP3. In order to confirm it and to check if it wasn't just a placebo effect, I did some ABX testing between a Wav file and 128kbps, 192kbps and 320kbps MP3s. I was able to easily hear the differences between the PCM and lower bitrates MP3s (128 and 192) and I got it right 100% just by focusing on the voices of the singers (Beegees). For the 320kbps, I got it right 7/10. But still, I feel that on long-term listening, FLAC or other lossless encoding offer a more relaxed and enjoyable sound than 320kbps.
Timbre :
The balance of the sound coming from the DAC-100 is very dependant on the OPA installed on it. The only OPA I tried are OPA-627, LM4562 and OPA-Earth. I didn't need to listen long to understand that the OPA-Earth was the clear winner, it has the most natural and dynamic sound of the 3. OPA-627 came second and LM4562 came last. I didn't try OPA 2134 because my unit was shipped with the Earth installed in it.
The timbre of the sound coming from the ST-3 is really outstanding. While you can easily get distracted in other gear by the boomy bass or the analytical highs, the ST-3 gives a sound that is balanced throughout the spectrum. In fact it seems to me that the ST-3 has a great midrange that extends in a natural and continuous way to the highs and low frequencies. While I used to think that the headphone output of the 0404 USB was very detailed in the highs because it was supposed to be transparent, I came to understand that I was hear a lot of distrotion.
In fact, I have to disagree with Kingwa on one point here. Once you give the ST-3 enough burn-in (at least 300 hours), the sound you get is nothing like tube-like but it doesn't have the digital harshness of the solid state gear I tried. The sound is very fast, clean and accurate while remaining very natural and very pleasing to listen to.
Soundstage :
The soundstage given by the system is huge and at the same time very focused.
Compared to the soundstage of the tubed Little Dot MKIII which is its major strength in my opinion, the soundstage of the ST-3 is almost as big but it is a lot more focused. The soundstage of the Little Dot seems a little fuzzy in comparison.
Also, the soundstage changes dramatically from one album to another and even from one track to another. For example, on Norah Jones 'Come away with me' album, you clearly hear differences between the tracks.
Note about the Moon Audio Blue Dragon cable :
All my review was done using the Moon Audio Blue Dragon V3 cable for my Sennheiser HD-650. When I tried the stock cable last out of curiosity, I found out that much of the characteristics described above (clean, fast, accurate, great midrange, highs and bass) are much more apparent with the Blue Dragon Cable. Through the Moon Audio Cable, the sound is cleaner (less distortion) and faster, the frequency extremities are more extended and the "veil" is lifted. If I hadn't listened to the cable I would have never been able to notice the deficiencies of the stock cable but now that I have, I can never go back.
Final thoughts
To sum-up I am very satisfied with sound using the DAC-100 and the ST-3. The sound is natural, fast, clean and transparent.
In fact it is so transparent that it was hard for me to review the gear. Each change in the interconnect affected the sound, so my review is probably biased by the quality of the cables I use, the Kimber PBJ and Canare Coaxial cable that were recommended a few years ago by Stereophile.
I have also to note that it takes a very long time break-in the Audio-gd gear.
But one thing is sure, I enjoy the sound of my system very much and I don't leave my headphones anymore either to listen to music or to watch movies.
Edit --- Comparison between the Compass and DAC-100 & ST-3 combo :
Since I haven't reviewed the Compass, I have to rely on Kingwa impressions.
According to him, the DAC section of the Compass should on par with the DAC-100 since they use the same components : AD1852, DIR9001, Nover capacitors ...
Also according to Kingwa, the amp section of the Compass is less coloured than the ST-3. It is supposed to be closer in sound character to the C2C than it is to the ST-3.
Part II: Optimization of the System
Well It has been around 6 months since my last review and I wanted to make an update to my review to share my experience with the DAC-100 paired with the ST-3 headphone amp.
My new Setup :
Foobar 0.8.3 (Otachan ASIO) ---> Wireworld ultraviolet USB ---> EMU 0404 USB ---> Hifi-Cables Sobek ---> Audio-gd DAC-100 ---> Hifi-Cables Khnoum ---> Audio-gd ST-3 ---> Moon Audio Blue Dragon v3 ---> Senneheiser HD-650
Power related Cables & Accessories : Hifi-Cables PowerTransPlus x2; Supra Mains multiplier; Essential Audio Tools Noise Eater (Parallel filter)
Other accessories : Vibapod cones, Vibrapod Isolators, plywood shelves, fiber carbon rigid sheets.
When I did my initial review in January I was unsure about how the ST-3 and DAC-100 really sound because of the limitations of the interconnects I was using at that time. Each time I changed interconnects I noticed improvements in some aspects but also drawbacks on other aspects.
Since January, I updated all my interconnects from Hifi-Cables a high-end French boutique that lets you borrow cables to try them for week before making your decision. And now, I don't feel anymore that interconnects are a limiting factor in my system (In fact, I am using a power cords that costs more than the ST-3)
So what were the changes to the sound ?
Well, the system improved in transparency, dynamics, soundstage and separation of instruments.
Transparency:
With the upgrades, I realized that the ST3/DAC100 combo was much more transparent than I first thought.
For example, when listening to the Pulse test track (which is recorded at a very low level) a lot of details become more easily apparent. Overall, it is like if I had lifted a few layers of cotton between my headphones and my ears.
I also found that I can "increase" the transparency even more by changing the Earth op-amp with the LME49720HA (a higher end version of the LM4562 that comes in metal can version). However I found that this op-amp is too revealing and a little more lightweight than the Earth op-amp. I guess that if I were doing monitoring work, it would be the opamp I will use since you can pick-up details easier than with the Earth Op-amp. I think that the AD1852 DAC used as a converter has a bit of digital sound that is masked through Earth HDAM.
Soundstage:
After the upgrades, I felt that the soundstage was not only bigger but also more focused at the same time. The soundstage extends well beyond my head with the Sennheiser HD-650 and on some recordings, there is a spooky 3D effect where you hear the instrument but also feel the person playing the instrument.
Also, when I listen to classical music, I don't feel anymore that there is a muddy mass playing. For instance, I can hear on most recording that distinct violins are playing on the left on loud passages while I used to hear sort of a one violin playing louder in intense passages.
Dynamics:
The dynamics also improved. While with my previous set-up I used to think that my system has nice dynamics, it made me aware that the Sennheiser are hard to drive. In contrast, now, I feel like the sennheiser hd-650 are some low impedance / high sensitivity headphones that can be driven pretty easily.
However, since I haven't listened to other headphone amps (such as DV337, audio-gd C2C, Lehmann Cube Linear, ...) I am pretty sure that there is still room for improvement on the dynamics side.
Notes about Media Players and Upsampling:
Before all those updates (interconnects, power conditioning, vibrapods, plywood and carbon fiber platforms ...) I used to prefer the sound with foobar 0.9.x with SRC upsampling. However, I realized now that while the upsampling brings some improvements (soundstage coherency, less digital sound, sweeter sound overall), it also lowers the transparency of the system. I feel like some small details are lost (or less apparent) with upsampling and that a kind of blanket is put between the system and me.
Finally I found that Foobar 0.8.3 (with Otachan ASIO) works best in my system. The next best player in my system is Media Monkey but I find it a little bit too much "hifi" for my taste.
Conclusion for Part II :
I have been enjoying a lot my system and I have been listening a lot more than before to music (especially classical music) so even after a few months, I am still happy with my purchase
But are there any "weaknesses" to the system ?
After a few months owning the DAC100/ST3 combo, I realized that the DAC100 (which is the DAC section of the COMPASS) has a little bit of digital sound. On live recordings, I feel like some instruments such as violins, or pianos do not sound as natural as on the real life.
This observation was further confirmed by reviews of people who own both a compass and a higher end DAC (such as DAC 19 MK3 or 19 SE). I guess that the AD1852 has some limitations in comparison to "better" DACs such as paralleled PCM1704-UK that you can find on the DAC-19MK3 or the Reference One.
Or maybe, I might be hearing he effect of jitter : the DAC-100 sounds better through its spdif input using the EMU 0404 usb as a transport. Also, I read in Stereophile that Multibit DACs (such as PCM1704 used in the DAC-19 MK3) have lower jitter than 1-bit DACs (such as the AD1852 used in the DAC100/DAC200/Compass). (Stereophile: Jitter & the Digital Interface)
Anyway, this has led me to a quest for a new DAC and I ordered a few days ago the DAC-19 MK3 from Kingwa.
The other (relative) weakness I found is that the DAC-100 / ST-3 (withe the ST-3 being the most sensitive) need really good power cords to sound their best. Those power cords usually come at a high price : I tried some entry-level power cords such as Olflex, Supra and a silver plated power cord (bought from ebay) but none of them come close to the Hifi-Cables PowerTransPlus.
Those weaknesses are only relative ones because even with a basic setup, the DAC-100 / ST-3 clearly outperform the other gear I have on hand (EMU 0404 USB, Zero DAC, Little dot MKIII, ...)
To sump up
Even if I am going to be shortly upgrading my DAC (case of upgraditis), I feel that I have reached a point where I have a very enjoyable music system. Even my non-audiophile friends tend to find my system "natural" and "lifelike". That usually was not their reaction for the few that had tried the EMU 0404 USB and Sennheiser HD-650 which did not seem to impress them nearly as much.
Also, I have been auditioning some speakers however I have been pretty disappointed : I auditioned speakers that ranged from 500€ to 5K€ that sounded bloated with low resolution.
The only system that surpassed (on most areas) the performance of my system was the JCT Heritage speakers (6moons audio reviews: JCT*Héritage AB). Those speakers made by the founder of Hifi-Cabes, act like a wide-bander : They have great resolution, soundstage and most of all you feel that highs and bass are perfectly integrated with the mids. When I listened to it, they were powered with heavily modified Atoll CD 200, stock Atoll PR300, stock Atoll AM200 and of course top of the line.
That is to say that I am quite happy with my current headphone setup and that I would need to spend a lot more to get comparable results from a speaker setup.
Part III:Comparison with Audio-GD DAC19 MK3
I have done a full length review of the DAC-19MK3 here for those who might be interested.
