Review of the Purepiper DAC A-1
I was asked by a fellow head-fier (on behalf of Purepiper) if I were interested in reviewing a DAC from a Chinese company I have never heard of before.
After accepting, Purepiper sent me pretty quickly their DAC A-1 and I received it about 2 weeks ago.
Packaging and Build Quality:
The Purepiper DAC A-1 came in a nice and professional package. In my case, Purepiper sent along with the DAC their usb to spdif converter (usually sold separately).
However, before even powering it up, I was curious to see the insides of this DAC. After opening it up, I was very impressed with the quality inside. It looked very tidy and well organized inside (pictures at the end of the review).
The first interesting thing for a DAC that is going to be selling for $170 (as I was told) is that it has 2 separate transformers inside: one for the digital section and another for the analogue section. This is a nice touch for an entry level DAC.
For the digital section, it uses the DIR9001 digital receiver. It is limited to 24/96 but it is has a lower jitter than the CS8416 commonly used in other DACs (40ps for the DIR9001 vs. 200ps for the CS8416). By the way, I have had the opportunity to try both digital receivers in the same DAC and I can attest that the DIR9001 is sonically definitely superior to the CS8416.
Anyway, while 24/96 (hi-rez) can provide an improvement over 16/44 (cd quality), it is mainly because it makes filtering easier. Anything beyond 24/96 is just marketing. So it is nice to see that Purepiper has not chosen the easy way (24/192) and preferred to offer a 24/96 that actually sounds better than the 24/192 one.
As for the DAC section, the DAC A-1 uses the CS4398. It is the top of the line Cirrus dac chip. It also uses the OPA2604 for the digital filtering. It is an audio grade opamp that is supposed to be better than the well known OPA2134.
As for the output stage, the DAC A-1 uses a discrete output stage with what seems to be 4 big output capacitors.
Overall, the choice of components is quite impressive for a unit sold at this price. I cannot but help to compare the insides of some commercial and well known DACs. The insides of the much more expensive PS Audio DLIII looks empty (and cheap) in comparison with the Purepiper. So even if the components used by themselves do not mean much, it is nice to see that a company is not cutting costs everywhere.
Setting-up the DAC:
The DAC A-1 has only 2 digital inputs: a coaxial and optical input. It doesn’t have a usb input which is a good thing in my opinion and here is why: In most DACs I have tried, the usb input was an afterthought and its performance level never approached that of the coaxial input. Even by using very cheap external usb to spdif converters, the performance is usually better than using the internal built-in. The reason behind that is because most built-in usb do not offer galvanic isolation from the computer. However, by using an external device and using the spdif inputs, you are providing the DAC with galvanic isolation (if the DAC or the usb to spdif converter are using transformers which they do most of the time). Also most built-in usb inputs are limited to 16/48. Only a few high end companies offer good usb solutions built-in into their DAC (Ayre, Wavelength, DCS...) but they never come cheap.
To cut it short, the DAC A-1 doesn’t have a usb input but it shouldn’t be discarded for that reason. Purepiper offers a usb to spdif converter that sells for $22 but it is limited to 16/48. For those who want to have 24/96 capability, they can probably go towards the Teralink-X2.
The Purepiper DAC A-1 was not extremely sensitive to tweaks (change in transport, digital cables, power cord). This is a good thing for an entry level product because it means that it should work pretty much near its full potential in most cases. This is contrary to the experience I had with the Audio-gd DACs which require a lot of care/tweaks before they sound their best. However, for the sake of consistency and fairness, I used the same source, digital cable, power cord, platform support... when I was comparing the DACs.
Main Chain used for this review:
Foobar v1.0 --> Kernel Streaming --> M2Tech hiFace BNC --> Oyaide DB-510 --> Purepiper DAC A-1 --> Artisan Cables "Ultimate Silver Dream" (or Kimber PBJ) --> Audio-GD C-2C (or Little Dot MkIII) --> Artisan Silver Cables --> Sennheiser HD-650
Power related accessories:
Hi-Fi Cables & Cie PowertransPlus Power Cords (x2)
Hi-Fi Cables & Cie SimplePower
Bada LB-5600 Power Filter Plant
Essential Audio Tools Noise Eater Parallel Filter
E&T Spider Rack, Maple platforms, Sandboxes, Brass cones, Acrylic and Fiber carbon sheets, Yamamoto footers, Herbie's Audio Lab Tenderfoot, SuperSonic Component Stabilizer
Some of the reference tracks used for this review:
Mozart Violin Concertos - Marianne Thorsen - 2L - 24/96
Sol Gabetta - Schostakowitsch Cellokonzert Nr. 2/Cello
Vivaldi - Concerto for 2 violins - Carmignola/Mullova
Keith Jarrett - Paris / London - Testament - 24/96
Glenn Gould - The Goldberg Variations 1981
Hans Zimmer - Gladiator Soundtrack
The Dave Brubeck Quartet - Take Five
The World's Greatest Audiophile Vocal Recordings - Chesky - 24/96
Diana Krall - Live in Paris
Norah Jones - Come Away With Me
Patricia Barber - Companion
Soundrama - "The Pulse" Test CD
Head-fi/Chesky Sampler - Open Your Ears - 24/96
Timbre & Tonal Balance:
Before getting into the description of the sound, I have to note that the Purepiper DAC A-1 is voiced a little differently than the audio-gd DACs I have been using these last months. It has a more upfront presentation that took me a little while to get adapted to.
Straight out of the box (before burn-in) the sound was thick, warm and soft (not very extended on top). After 200 hours+ of burn-in (mainly using the Isotek Burn-in CD and some 24/96 files during that time), the sound became a lot clearer and more extended on top (those big output coupling capacitors probably need a lot of running before to settle-in). By the way, I only listened for a few minutes at a time during the burn-in process, so it was the component and not my ears that burned-in.
Overall, the sound balance is rather on neutral side: it is neither bass heavy nor it is treble lifted. But it has a slight upper mid/lower treble brightness.
The extension at both frequency extremes is pretty good (better than the EMU 0404 usb, audio-gd DAC A-100/Compass DAC). It is only when directly compared to a better DAC such as the DAC A-19mk3, that you feel that it is missing that last bit of extension in the deep lows and deep bass.
However, I have one (small) complaint about the tonal quality of the DAC that I didn’t realize until I listened for a few hours. While I first thought that it was more detailed and extended than the twice more expensive Audio-gd FUN, I kept feeling that something was missing.
That missing thing hit me when I played the “Use Me” from Patricia’s Barber “Companion” Live album. The Bass playing at the beginning of the track sounded wrong. I listened to the same track with the DAC A-19mk3 and FUN, and I realized that it was much drier through the Purepiper DAC A-1. Once I put my hand on that lack of richness of tone, it became quickly apparent on other tracks as well.
However, that relative dryness can be quickly overcome: when using the warmer Kimber PBJ interconnects (instead of my reference interconnects) or when using the Little Dot MKIII headphone amp (instead of the C2C headphone amp), the missing warmth reappears but at the expense of other qualities (soundstage, low level details...).
That relative dryness of tone was small enough that I still did most of my listening with the Artisan Silver Cables and C2C amp (the Purepiper is a tonally richer sounding DAC than the EMU 0404 usb for example). But it would be probably a bad idea to pair the Purepiper DAC A-1 with bright/sterile equipment as it could become quickly fatiguing.
To sum up, I would say that the Purepiper DAC A-1 has a nice frequency extension at the extremes, it is relatively neutral (with the exception of that slight upper mids emphasis) and the best tonal balance is achieved when paired with neutral or slightly warm components and interconnects.
As a comparison, the Purepiper DAC A-1 is clearer sounding DAC than the Zero DAC but it is not thin sounding like the EMU 0404 usb for instance.
Soundstage & Imaging:
I was very impressed by the size of the soundstage and the quality of the imaging.
In my headphone set-up, the soundstage extends well beyond my head regardless of the transport used. Some DACs are very dependant on the quality of the transport (CD Players, usb to spdif converter, sound card...) and can sound constricted with a jittery source. This was not the case Purepiper DAC A-1 as it has a nice a big soundstage regardless of the source.
I also have to note that the size of the soundstage varied from one track to another. Some components can give you a big or small soundstage regardless of what is recorded. The Purepiper DAC A-1 is good enough to let you hear reliably if the recording venue was big or small or if the recorded event was in a studio or live event....
The imaging was also pretty good and better than expected from a unit of this price. I remember than when I compared the dac19mk3 against the €3000 Audiomat DAC 2.6, I was surprised with the poor imaging of the Audiomat where everything sounded diffuse (in space).
If the equipment downstream is good enough, the Purepiper DAC gives a pinpoint location of instruments/performers in the soundstage in both the width and depth directions. What it fails to do in comparison with better (but also much more expensive) DACs such as the dac19mk3 is to give you 3D/hollographic representation.
The Purepiper DAC A-1 has good macro dynamics with no discernable compression. When listening to the demanding Battle track from Gladiator, the DAC A-1 doesn’t run out of steam. In comparison, listening to the same track with the EMU 0404 usb, the track sounds compressed.
However, I have to note that the way it portrays micro dynamics is not the Purepiper DAC A-1 biggest strength. I felt that the Purepiper did a better job handling macro dynamics than it did from the more subtle micro-dynamics.
However it is important to note that those sonic characters are subtractive and not additive. What it means is that you can be pretty much satisfied with the dynamics unless you listen to better equipment.
It is a relatively transparent DAC: it respects what is on the recording. The sonic signature is relatively minimal as it respects the tonal balance and soundstage differences between recordings. What it means, is that you don’t get a constant sound signature with the Purepiper DAC A-1. When recording are overly smooth/warm, you hear it and when they are forward or over processed you also hear it.
The slight emphasis in the upper mids and lower treble increases the “perceived” transparency. The voicing gives it a vivid sound signature. In a resolving system, it can become tiring but in most entry level systems, it will be probably give it the edge in A/B comparisons.
When listening the head-fi/Chesky sampler, you realize that there is a little simplification of the message and you don’t get that “you are there” feeling. However, at now time the message gets confused or anything. So the Purepiper DAC A-1 has a achieved a good trade-off between transparency and tonal density. The makers of the DAC A-1 could have probably made it more “transparent” (by choosing another opamp for example) but the result would probably have been a thinner over-articulated representation of the sound.
It is also important to note that it behaves better with high quality recordings and with lossless files. On poorly encoded (and/or) files, the Purepiper can increase sibilance. This excessive sensitivity is not a sign of real transparency (in my opinion) but more of a characteristic of the most sigma-delta dac chips (the Purepiper uses the CS4398). For example, while the dac19mk3 (which uses a mutlibit R2R dac chip) is a more resolving dac, it is also more forgiving towards low quality files.
Anyway, it is important to feed the Purepiper DAC A-1 at the very least high quality MP3 files (256 or better), or better lossless/high rez encoding.
While I might have sounded critical, I just wanted to give an accurate picture of what to expect from the Purepiper DAC A-1. When buying audio components (especially the budget ones), it is always a compromise. That is why I tried to describe as accurately as possible not only the strengths but also the weaknesses. While the qualities are what catch our ears at the beginning, the weaknesses are what we have to live with the long run.
At $170, the Purepiper DAC A-1 did a great job at maximizing the qualities and minimizing the weaknesses. I have listened to many DACs and CD players that sounded “broken”. The Purepiper DAC A-1 is definitely not one those DACs.
Given that the Purepiper DAC A-1 is likely to be used with entry level amps and headphones, I would say that it is likely to be overkill for those situations. Overall, the Purepiper DAC A-1 offers a tremendous value for the money in my opinion.
Follow-up – 04/04/10:
Last week, I took the decision to upgrade my former reference system by replacing the older audio-gd dac19mk3/C2C combo with the newer offering: dac19dsp/ACSS/C2.
While waiting for the delivery of the dac19dsp/c2 combo, I had to assemble a temporary system with what I had on hand.
I first thought that I would settle on the Audio-gd FUN alone but after doing a little bit of experimenting, I found out that I got the best subjective (and most satisfying) results by running the Purepiper DAC A-1 into the Audio-gd FUN headphone amp.
So during these past few days, I have had the opportunity to listen a little bit more to the Purepiper which motivated me to write this little follow-up.
After re-reading my review, I realize that I described many times the Purepiper DAC A-1 as having a slight mid treble brightness. While that was clearly audible with the C2C headphone amp, it is far less audible with the FUN headphone amp which is more forgiving (and less resolving) than the C2C headphone amp that I used for the review.
My test set-up for the review (a revealing amp, pure solid core silver interconnects and headphone cables, high end power cords...) was probably not very representative of the situations that the Purepiper would likely to be used with. When using a slightly less resolving headphone amp, most of those sonic faults disappeared.
Does it mean that I can live happily ever after with the Purepiper DAC A-1?
The answer is no simply because I spent many months with a better DAC which made me aware that it is possible to have a better sound from a digital source.
However, if I were coming from an entry level gear such as the Emu 0404 usb, the Zero DAC or a regular soundcard, I would have been extremely happy with the Purepiper DAC A-1 as it represents a tremendous value in the hi-fi arena. In fact, in order to not limit the performance of the DAC A-1, one would have to use high performance interconnects that usually retail for a higher price than the DAC itself.
Overall, I am once again impressed about the performance level of this DAC that is selling for so low. I highly recommend it for those looking for a sub $200 DAC.
Bixby comment on the Purepiper DAC A-1 (w/ comparisons against the Benchmark DAC1 and Apogee Duet):
I have had the Purepiper for several weeks now and have had it in my main system where it shared some time with my Benchmark DAC1 as well as in my office system where it replaced my other Benchmark DAC1. I really cannot add much to the impressions above by Slim.a. He did a great job characterizing this dac. It is a pretty nice piece of equipment for the $.
In my main system, it did a great job of reproducing a flat frequency balance. Compared to the Little Dot Dac for instance it was much more natural and did not exhibit the excessive plumbiness in guitars and upper bass that the LD does. Also highs were a bit on the restrained side but not at all tipped up like so many lower costs dacs. It did a good job of resolving details and space although compared to my Benchmark one could easily hear the difference that spending 5X more dollars brings.
Unlike Slim.A I did find that the Purepiper like most dacs is dependent on a good transport to sound it's best. From my Macbook via very high quality Glass toslink it did a good job but was just lacking a bit in dynamics and space between instruments compared to the $1k dac. When I tried the USB to spdif adapter that is also made by Purepioer I could hear that the noise floor crept up a bit and that highs were now more prevalent as well as bass. Upon further listening the highs revealed a bit of brittle metal tone that I have heard on other usb implementations. Perhaps it is the electrical noise coming through he USB connection as well as some USB jitter. The sound-stage also sounded a bit off. Vocals a bit too forward. Overall I liked it best via toslink with the mac. Even when I tried the Halide bridge I still preferred toslink. With the Halide the sound had become better separated but lacked warmth (which I know is on the recordings). the Halide also seemed to strip a bit of chest away from female vocals like Diana Krall. Detail of breath and mouth were increased but body decreased.
In my office system being fed by the Apple TV, jitter made it sound like the sound-stage was contained between the speakers just like it had with the Benchmark but with less detail and resolution of instruments and voices. Highs did not have the dynamics or extension of the Benchmark. But given that the ATV is not the best transport out there, it did well enough that if I had not owned or heard the Benchmark in this system, that I might be fairly happy with the Purepiper and the AT. It was not until I fed the Purepiper with the coax out of my Opera Droplet CD player that I really heard how the Purepiper can sound. Increased resolution, much better sounds-stage width and cleaner highs as well as more weight to the bass. Even with the jitter reduction capabilities of the DIR9001 receiver chip, it seems a lower jitter transport will sound better with the Purepiper dac. Perhaps my new Logitech Touch will have lower jitter and will get me close to how the Purepiper can sound with my CD transport.
On a final note, I will say that the Purepiper is receptive to power cord changes and the tone of it like may dacs can be tuned if you will by swapping cords. Since it doe snot come with a power cord, one must find a suitable one. It sounded nice with my vintage Volex cord and even weightier with my VH Audio Flavor 4. Feels kind of wierd putting a $250 cord on a $225 dac, but at least the Volex was only $15 back when I bought a half dozen of them.
All in all the Purepiper is a very nice dac for the price and better than the Little Dot DAC2 that I had for a short time. No one will mistake it for a $750 dac like the EE minimax or the PS audio DACIII. The PS is without a doubt the best sounding dac under $800 that have heard and could easily live with it versus the Benchmark. They are just different flavors. I will also say that the Pupepiper may also be preferred to my favorite under $500 dac, the Apogee Duet. The Duet is more musical but a bit less natural in freq response, so if you like a less romantic sound and can live with a little less dynamics then the Purepiper might be a good choice.
The Purepiper dac is also quite revealing of the digital source. Using PureMusic I found hog mode and upsampling to 96khz to sound the best with the Macbook. I also found that running it direct to my amp and bypassing my pre made for the most transparent sound.
One final note, all listening was done on nicely resolving speakers in both systems since my headphone amp was my Benchmark dac1 in the past. PICS HERE http://www.head-fi.org/gallery/album/view/id/7658/user_id/17837
That's about all I can say for now, well done Purepiper.
Edited by slim.a - 11/4/10 at 10:37am