2011/03/04
아래에 갈무리는 할스 한센이 오포 83의 어떤 부분을 어떤 식으로 다르게 만들었는지 상세히 설명한 것입니다.
에어는 OPPO 83 완제품을 사서 그 제품에 포함되어 있는 여러 부품을 재사용했지만 완전히 새로 만든 부분이 많네요. 전원부 외에도 Main PCB 까지도 완전 새로 만들었다네요.
에어 DX-5의 HDMI 출력 소리가 좋은 이유는 이곳저곳 꼼꼼하게 음질에 좋도록 설계한 것이지만 그중에서도 "Audio Rate Control" (ARC)를 제대로 지원하는 것을 강조하고 있습니다.
ARC기능은 HDMI1.3a 규격에 새로 생긴 것인데, (CEC라인을 이용하여) HDMI 케이블을 피드백 파이프라인처럼 사용하는 기능입니다. ARC를 지원하지 못하는 경우는 플레이어가 마스터 클럭을 송출하고 AV 프로세서/리시버는 슬레이브가 됩니다. 반면에 ARC를 지원할 경우에는 AV 프로세서/리시버가 신호를 요청하는 대로 플레이어가 제공해 준다고 하네요. (플레이어는 속도를 조절해서 AV 프로세서/리시버의 요청에 따릅니다)
놀랍게도 AV 리시버의 최대 강국 일본에서 이 기능을 편협하게 사용했다는군요. 파이오니아와 소니는 자기네 제품끼리만 ARC를 사용할 수 있도록 했었다네요. 파이오니아에서는 PQLS이라는 이름으로, 소니에서는 HATS로 적용해 왔습니다. 그래서 에어 DX-5의 훌륭한 HDMI 성능이 소니나 파이오니아 리시버에서는 제대로 동작되지 못할 수도 있겠네요. 하지만 파이오니아는 서라운드 프로세서를 만들지 않고 소니는 AV리시버 시장에서 명함을 내밀지 못하고 있으니 별 문제는 없지 않을까 싶습니다. 설마 에어 DX-5를 사용하는 사람이 AV 리시버를 사용하지는 않겠죠?!
아래쪽에 있는 " > " 모양의 아이콘을 클릭하시면 AVS forum의 원본 Thread로 연결됩니다.
Quote from Charles Hansen Avs forum,
How to make an Ayre
Quote:
Originally Posted by mmiles
I wonder what Ayre does to a $500 unit to make an "Ayre"?
Well, first of all you have to remember that we don't have to pay $500 for the unit. We buy in quantity, so Oppo gives us the spectacular discounted price of (make sure you are sitting down, please!) $400.
Then to make it an Ayre, we dismantle it completely and recycle everything except the main PCB (with the video decoder, ABT scaler chip, and HDMI transmitter), the transport mechanism, the VFD display, and the remote control handset.
Next we re-build the main PCB. The big switching power supply only provides 5 VDC, then there are little mini-switching power supplies (called DC-DC converters) on the main PCB that turn the 5 VDC into 1.0 VDC, 1.1 VDC, 1.8 VDC, and 3.3 VDC. All of those are removed. There are also USB power switches that allow hot-plugging of USB devices. These are removed as they have another kind of DC-DC converter called a "charge pump".
All of the supplies are replaced with pure linear supplies with analog regulators. The USB power switches are replaced with devices without the charge pumps. Now we have gotten rid of seven noise sources that create high-frequency square waves with harmonics well out into the MHz region. Getting rid of all of that noise creates a visibly cleaner picture.
Next, we replace the low-quality master video clock with a VCXO. This becomes more important later on, as you will see.
Now we start adding things back in. First is our AyreLink communication system. It allows AyreLink equipped components to act as one big system. For example, turning on the player will turn on all of the downstream components as well as automatically select the correct input on the preamp. We also make an external RS-232 to AyreLink converter box for system controllers like Crestrons. The AyreLink system has opto-isolators between each component to avoid unwanted ground loops, which is why we don't use RS-232 inputs on any of our equipment.
Then we add a custom programmed FPGA on the front panel PCB to do some housekeeping. It intercepts the appropriate commands and translates them to operate the AyreLink system. It disables the internal volume control (which operates in the digital domain and degrades the sound) and instead routes the volume changes to an AyreLink equipped preamp. It also allows us to send custom messages to the front panel VFD display. So when the USB audio input is activated, it will report that on the front panel along with the sample rate of the received signal.
There are a bunch of boards added on the audio side. I say "side" because we literally split the player into two parts. There is a separate power transformer that runs all of the audio circuitry, which is separated from the video side by a bank of opto-isolators. So the audio and video "sides" have separate grounds that are completely galvanically isolated. This is the only way to get the best performance from either your audio system or your video system.
All video displays have switching power supplies that dump noise into your system in the absence of such isolation. There are also ground loops that are inevitably formed as there is no such thing as a balanced video connection. All of those problems go away with our isolation system.
The ten-channel audio board is replaced by a two-channel audio board. Everything on this board is top-quality, with discrete, fully balanced, zero-feedback audio circuitry and discrete, zero-feedback power supply regulators. There are improvements in both the parts quality and circuit design that give it even higher performance than the QB-9 USB DAC that was recently rated "Class A+" in Stereophile's recommended components issue. For two-channel disc playback (CD, SACD, DVD-Audio), the performance exceeds our $6,000 audio-only disc player.
We also add the USB audio input that allows you to connect your personal computer and turn your system into a music server. Your entire digital library (except SACD's, thank you very much Sony -- not!) can be stored on a hard drive and played back with the click of a mouse. So this one component can be the only source component that you need. This input is also connected via a bank of opto-isolators, so there is actually a *third* "side" to the system -- the video, the audio, and the computer. The noise from your computer and its switching power supply will not be connected to either your video or audio systems.
We also add a second audio-only HDMI connector. This is fed by the isolated signals on the audio "side" so that it won't contaminate your surround-sound system if you choose to connect one. It also supports the new "Audio Rate Control" (ARC) feature that is part of the HDMI 1.3a specifcation. This is a breakthrough for the surround-sound enthusiast, as HDMI is normally the worst way in the world to send audio data -- the jitter is even worse than the lowly S/PDIF connection.
But with ARC, the surround-sound processor uses a local crystal oscillator to provide a low-jitter clock to the DAC chips. Then there is a buffer that stores the incoming audio data. When the buffer is too full it sends a signal back upstream to the Blu-Ray player telling it to slow down the disc slightly. When the buffer is too empty, it asks the disc to speed up slightly. Now the audio clock is in charge, the way that it should be. (When the unit is running in two-channel mode, the local low-jitter, fixed-frequency crystal oscillator provides the master audio clock.)
With a modern digital display (plasma, LCD, LCOS, DLP, et cetera) jitter on the video signal does not matter. Since there is no conversion to analog, the digital signal values are simply stored in a frame buffer until needed.
Then the whole thing is put into a custom chassis made entirely from anodized aluminum and stainless steel. We want our products to look just as good 50 years from now as they do today. There are other people making Oppo "clones". One of them only replaces the chassis. Another replaces the power supply also. Nobody is rebuilding the complete player and adding the extra features and advanced technology that Ayre is.
As far as the value, it is up to you to determine that. I can't tell you how much an improved picture is worth. I can't tell you how much better sound is worth. I can't tell you how much the features we add are worth. You will have to decide that for yourself.
What I can tell you is that, just like all of our other products, they offer engineering and performance beyond what anyone else is offering, at a fair price that reflects our cost of manufacturing, and that we back up our products with both a strong network of the finest dealers on the planet and an incredible service policy.
Unlike other manufacturers that try to sell you a "new and improved" product every year or two, when we figure out a way to genuinely improve the performance of our existing products, we offer upgrades to current owners at very reasonable prices. Go to the Audio Asylum and check out some comments regarding our recent "MP" upgrades to the C-5xe and CX-7e disc players, for example.
If you want a great Blu-Ray player for an incredible price, buy the Oppo. If you want the best picture and sound quality in the world for your home theater and price is not a concern, check out the Ayre. And no, it will not be available in November, sorry. Early next year will be a better guess.