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a short diary of some part of my life.

Posts tagged PCM1704UK

Audio-gd isn’t a well known audio company brand in the US yet!. The company is led by Mr. He QingHua (Kingwa), the First Prize winner of the American National Semiconductor Audio Design Contest. Kingwa designs his gear based on his  extensive research on high end audio equipments. He’s been listening to his customers all along, including following discussion threads at many audio forums. There are three products that came to fruitions because of customers’ demands; first the Compass (Amp/DAC combo), the Panther (a power amp), and the Phoenix (a fully balanced headphone amp/pre-amp).

I’ve been using the Audio-gd DAC 19Mk3 for a few months and I‘m very happy to report that this is my favorite DAC, compared with:

  • NuForce uDAC-2 ($129 USB DAC)
  • Mhdt Havana ($749 ~ typical NOS DAC sound signature, sounds warm and pleasant)
  • Pico amp/DAC ($499 ~ small, err… tiny, there is nothing wrong with the SQ considering its’ size :D)
  • AMB Gamma 2 ($230-parts cost only ~ superb DAC for its’ small size, my second best DAC, it sounds neutral, you can also drive a headphone from one of the analog outputs)
  • And, a few other famous DACs…

I tend to buy a few things at the same time for my curiosity sake. If I don’t like it, I can always sell it or return it. I’m pairing the Audio-gd DAC-19Mk3 with Audio-gd P-2, D-Sonic Magnum 500S (2X250W / 8Ω | 2X500W / 4Ω; ICE Power), and Selah Audio RC3R (3 way monitor; Fountek ribbon tweeter, Morel dome midrange and Scan-speak woofer).

The DAC-19Mk3 uses two Burr-Brown PCM1704UK – R-2R/multi-bit chip, one chip per channel. It’s a single ended DAC with two sets of RCA outputs. The PCM1704UK is considered to be the best sounding DAC chip. Manufacturers are now favoring Sigma-Delta chips due to its ease of manufacturing (cheaper to produce) and features that can be implemented in the chip (built-in digital filters, anti-clipping; take a look at Wolfson’s top of the line DAC, WM8741 that can be found in PS Audio PerfectWave DAC). They no longer consider sound quality to be the top priority in making those chips. Those claims above may be argued by some people, but the PCM1704UK is still used by some of the best DAC designers and the chip can be found in some of the most expensive DACs. The D/A chip is irrelevant to judge a DAC unit sound quality, what really matters is its’ implementation.

There are two digital filters can be used in the DAC-19Mk3, the Pacific Microsonics PMD100 (a 24/55 HDCD digital filter) and the Burr-Brown DF1704 (a 24/96 digital filter). All the processing/filtering after the DAC is done in the current mode – ACSS which is a lot less harmful to the sound than voltage mode. Each PCM1704UK has its’ own ACSS module. The Audio-gd ACSS technology is inspired from Krell who is the proprietor of the current gain technology. It has zero feedback analog stage, DC coupled, and discrete output stage – there is no op-amp, no coupling capacitor on the signal path.  to purify dirty power and provide the cleanest power to the digital board and analog stage. There are two beefy R-Core power transformers, each of them serves different purpose, one for the digital board and the other one for the analog stage. They are carefully shielded. Those are not marketing hypes, they are just good designs.

It has 3 selectable inputs: Coax (RCA), Optical (ToSlink) and USB. One can ask Audio-gd if one needs different (Coax RCA – BNC) or more inputs. The USB input uses the commonly used PCM2707 USB receiver to convert the USB signal to S/PDIF. I have read a few decent articles that claim i2s signal is better for USB input. I used it once for my curiosity sake and the sound was decent. I don’t really care about this as I rarely use the USB input. I also found out that the DAC-19Mk3 is able to output ACSS (CAST) signal if needed, you just have to swap one set (there are two sets of RCA outputs) of the RCA outputs to ACSS (CAST – 4 pin) outputs. That if you own an amp or a pre-amp that accepts ACSS (CAST) inputs. For those who will be using the USB input exclusively, you might be interested in shutting down the S/PDIF inputs when using the USB input by installing a jumper to get an improved SQ. Here is a picture to show how to do it:

Let’s see where this DAC excels! The power supply is monstrous, Kingwa designed the DAC to have superb power filtration. It has 8 groups of parallel Class A voltage regulators to purify dirty power and provide the cleanest power to the digital board and analog stage. The noise floor is suppressed to the lowest level possible – no audible noise at all. Sub-par products tend to perform mediocre when fed with dirty power due to their poor power supplies. Switching power supply is also a big no-no, a regulated one is generally preferable for high end audio electronics. Clean power is very essential for any audio or electronic products, insufficient power filtration may produce bad results and also shorten the life of the circuits. Almost half the size of the DAC-19Mk3 is used for the power filtration, one does not need to worry about getting a power filtration/regenerator unit or a fancy power cord (snake oil!).

~ I tried various power cords for my curiosity sake, none of them improves the SQ or sound different. I have also tried various interconnects from Blue Jeans cable, ‘SPC (silver plated copper) head-fi.org sponsor’ cable, Cryo-parts SCSCag wires, all of them sound exactly the same. Unless your cables are mediocrely built, I don’t see the point of buying these fancy cables other than for their looks. All these expensive fancy cables are merely jewelries that do not add anything to the music ~

DAC-19Mk3 without digital filter board and ACSS modules installed

The Sound

About the SQ… it’s a superb DAC. This DAC completely surprised me during my first listening session with a whole new set of audio gear. I have always thought that the Audio-gd Phoenix (headamp/preamp) is no where as dynamic as some of the best headamps out there, I thought similar sound signature could also be found in the DAC-19Mk3. The single ended Audio-gd DAC (19Mk3) is well, different. It is very dynamic and at the same time, not harsh at all. This DAC makes me appreciate good recordings and instruments. There were times when I thought certain instruments sounded weird when played directly from my sound card, a PS3 and an iPod; the 19Mk3 corrects all faults in my system, every single instrument sounds right to my ears. The vocal is silky smooth, it does not have any digital trace at all. The soundstage is huge, grand soundstage. You won’t get the DAC-19Mk3’s soundstage and incredible dynamic with a NOS DAC, its soundstage is a lot smaller than what the DAC-19Mk3 can produce, NOS DAC also sounds recessed, very recessed if one compares them side by side. Now, I understand why some people like NOS DACs’ sound signature, it’s easy on the ears. The DAC-19Mk3 sound placement is superb, it is never in-front-of your face, it’s like hearing a live performance! The background is very black, one can easily notice tiny details in the recordings. There are layers of details, one can easily pin-point instruments that are playing. This is the most analog sounding DAC that I have tried. Everything seems to be natural, dynamic, and very well balanced. I couldn’t find anything wrong with the SQ. The bass gets low and impactful. I am honestly amazed by this DAC, it is a giant killer. The DAC-19Mk3 is quite neutral, this is a plus: good recordings would shine, but bad recordings were still bearable or even enjoyable if one liked the music enough to accept the poor recording. Being a music fanatic first and audiophile second, I tend to listen to a number of poor recordings as well as very good ones. 😎

If I were to point out areas where I want the 19Mk3 to be able to do a little more is the bass impact. I’m not a bass head, perhaps my transports aren’t good enough (Arcam CD36, Squeezebox Classic, and M2Tech hiFace) but I have not been able to find any major sound quality difference between them. I don’t see the need of getting a big and expensive transport unless my current transport is very bad and affecting my system’s sound quality.

I’m very impressed with Kingwa’s attentions to details, every single part of the DAC seems to be well thought out. I’m also amazed by Kingwa’s decision to salvage any (Pacific Microsonics) PMD100 from used audio equipments. PMD100 is no longer made and is getting rare to find. As mentioned above, I can choose to use one of two excellent digital filters, the musical PMD100 and the neutral (hi-fi) DF1704. The PMD100 produces musical sound signature which suits classical, jazz, female voices, basically anything slow. If I want more impact and neutral, I use the DF1704. The bass has noticeably increased, it goes deeper, and produces more details but the soundstage seems to suffer. PMD100 (laidback) is preferable for forward sounding speakers while DF1704 (forward) is better for laidback speakers, it’s all about balance and synergy.

Audio-gd PMD100 board

Build Quality

For those who care about the build quality and chassis work, the innards look quite good but it’s definately not at the same level of finesse of HeadAmp (Justin Wilson) which I consider to be one of the very few manufacturers who craves for perfections. There is a few major concerns about the build quality and there are some minor imperfections, such as: a few not-so-good soldering jobs, bent PCB, many traces of glue on the PCB, and parts are not aligned as neat as HeadAmp. This DAC looks almost like a DIY unit. My AMB y2 looks much better inside out. The chassis is as simple as it can be, it works and it is very sturdy but it’s far from a Grade A chassis. The plates are not aligned perfectly, there are gaps between plates here and there. My DAC-19Mk3 top plate is hard to pull out due to incorrect size of the top plate. These are just some minor shortcomings that have nothing to do with the sound quality. I would rather have a well designed innards than a beautiful chassis that may cost up to half the price of the unit and skimp on the quality of the components inside.

This is one hell of a DAC. I can’t imagine how good higher end Audio-gd DACs are after using this DAC. I bet it’s a huge step up above the DAC-19Mk3. This DAC is priced at $480 + shipping. I don’t think I can find any better DAC at that price point. All brand names DACs that I have auditioned above are not even close to the DAC-19Mk3. I don’t usually buy ‘Chinese’ products if I have the chance to choose. Off course, almost all electronic products are now made in China, not that it matters but I had a sheer experience of buying unknown ‘Chinese’ made products that failed to meet my expectations in the past. This is simply not the case with Audio-gd, superb designs, superb executions and zero marketing BS (unlike many major brand names who sell more marketing that the actual product itself :mad:). Thanks Kingwa, for making this excellent DAC! Oh and, you might want to pick the PMD100 as the digital filter or your super backup, the supply is running low. If you send an email to Audio-gd, don’t be surprised by their difficulties of answering questions in English. They usually reply within hours.

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