版主
俱乐部理事
- 积分
- 3761
- 注册时间
- 2001-11-21
  
|
发表于 2007-12-18 17:26:33
|
显示全部楼层
这里有一篇国外的专业评论,出自荷兰HI-FI网站. 看得懂英文的请仔细看. 推荐对MINI-DAC感兴趣的朋友们阅读. 我翻译了最后两段结论部分的总结文字.
Apogee Mini-DAC
To the returning reader of this site, Apogee’s Mini-DAC is not a stranger. Rene van Es’ favorite little one is being put on the test bench once again. For two reasons: to start, the Mini-DAC is easy to hook up through USB to the computer. Both Mac OS X and Windows XP did recognize this device instantly; no additional drivers were required to install. It did not even require a restart. However you do not have the electrical isolation, USB is not optical. There is also a limitation of 24/48 with USB. Which is not a major problem, since most audio on your drive will be 16/44.1. More important is the 215 Euro price for this USB option. A high quality optical cable and if required a soundcard with optical, will be much less.
One of the important reasons to pull in the Apogee was, because it seemed, after reading Van Es’ review, the best DAC in the price range below “grand-masters” like Burmester and Mark Levinson. Needless to say there is a giant gap in price. Even better news is that the price has come down since Van Es’ review: 1115 Euro without USB (was 1285) and 1330 with USB (was 1625).
It is almost embarrassing to tell how I had my first listening experience with the Mini-DAC, but since it is kind of informing, I am going to do it anyway. The Mini-DAC was the first device to arrive, but it was, awaiting the big shipment of Oehlbach, not connectable. There is analog output on XLR and line on mini-jack. On the front there is 6.3 mm headphone jack. I loaned my Senheisser 580 and my mini-jack to RCA conversion cable to a friend, 200 kilometers from here and my Kenwood 7090R does not have XLRs, so I had only one option: the ear-buds of my iPod.
That worked fine with the adjustable line output on the back of the unit. To be more accurate, it worked very well. Wonderful. I would not say the sound was perfect, the headphones do not allow for such a thing. But with these humble ear-buds I did hear a lot of details that escaped my attention before. I have been listening for more than an hour with my head in close proximity of the Apogee (since the cord of the iPod phone is really short), while changing one cd after another. It made me run to a friendly electronics store in my current city for a XLR to RCA cable. They had them…
At that point the teamwork of Philips/Mac-Apogee-Kenwood-B&W revealed a quality almost unheard. But before I get into it, a brief technical description of the Mini-DAC: Adjustable outputs (XLR, line and headphone), S/PDIF, AES/EBU and ADAT in, through 2x AES/EBU, Toslink and coaxial. The Mini-DAC accepts signals up to 192 kHz. With the USB option, it will not only accept signal from the computer, it will also pass other digital signals from external gear, for instance MD and pass it through USB to the computer.
One of the reasons the Mini-DAC sound so good is, according to Apogee’s manual:
The clock circuitry of a typical D-to-A converter must be designed as a compromise between the ability to attenuate input signal jitter and the ability to accept any bitstream, regardless of its stability. The more the clock is allowed to track timing variations of the input, the more jitter remains in the clock at the conversion stage, with the degradation of conversion quality as a result. The Mini-DAC’s Dual Stage Clock overcomes this compromise by employing one clock stage to accept the bitstream and store bits in a buffer, and a second stage to clock bits out of the buffer to the conversion stage. The first stage is optimized to track timing variations of the input, while the second stage is optimized to attenuate jitter and ensure that conversion takes place with the lowest jitter clock possible.
There is no doubt that the bitstream needs to be free of jitter when converted to analog, but that is not a guarantee for top quality. The Mini-DAC gives the impression they have been thinking just as much about the rest of the design as on the digital input. To illustrate, the powersupply of the Mini-DAC is a super high speed switcher. The external supply, a table top, is nothing but a DC source. Inside the Mini-DAC this DC is being converted to ultra-high frequency AC (in the range of 750kHz) a multiple of the sample rate. Next, the AC is being reconverted to normal DC. The advantage of this system is the high tolerance for any type of external powersupply (the Mini-DAC accepts DC from 6 to 14 Volt, with a minimum of 1.25 Amps). The noise of this procedure is way beyond the audible range and the response time of the circuitry is fast enough for transient up into the inaudible. Apogee claims that there is an overcapacity locally and within the power supply, resulting in a total elimination of garbage, noise, DC within the power net. This is an expensive solution, but it is very effective.
But most of all the Mini-DAC shows there has been done some extensive listening during development. For instance while I am writing this, I see next to my text program a window that displays the DVD Live at Madison Square Garden van Pearl Jam. I have to say it is very distractive. I knew it was an amazing recording (even though the quality of the picture of the PAL version is to cry for), but I do hear more details, more separation, a better image and improved dimensions. Suddenly I am not that convinced anymore to make the switch to surround in the near future. (Wishing that all DVDs had a decent stereo track...) When I get really tired of the distraction (I have to write, remember) I launch iTunes. An album like Beach Boys’ 'Holland', recorded in Baambrugge (Netherlands, 1973 and recently released on cd), brings out the quality of the Mini-DAC. The two mini-symphonies on this record, A 'California Saga' and 'Trader' became apexes of musical creativity, more than I ever experienced, just with the Mini-DAC. It suddenly becomes apparent what an enormous energy the Beach Boys put in their arrangements.
Next to the standard rock band instruments, the beach dudes play flute, piano, harmonica and instruments I do not really know the name of. The boys’ close harmony vocals are just perfect on this record and are really convincing with the Mini-DAC. The Beach Boys are seated on a wide virtual stage and the depth remains extremely stabile.
With Carl Wilson’s 'Trader', his voice is so real and saturated with emotion. The very subtle percussion of this song, which is really demanding of the timing of the DAC, is convincing and extremely rhythmic. The Bottom line is, an excellent performance.
I can go on forever. But instead of telling how every one of my CDs or MP3s sounds through the Mini-DAC, I refrain to saying this. The Apogee is equally convincing with, rock, pop, jazz and classical. It has fantastic features for everyone: it convinces in timing, emotional contents, unique and authentic vocals; a sweet, never intrusive high with just enough clarity, an ever contained and dimensional soundstage, which transposes far beyond the loudspeakers. Low response and dynamics are never compromised with the Apogee: when required, the Mini-DAC displays a dynamic range I did not consider my equipment being able to reproduce. There was no music in my collection that did not give me a whole new experience with the Mini-DAC. I could not find any disadvantages…
(译: MINI-DAC播放摇滚,流行,爵士乐,古典音乐同样令人信服. 对每个人来说它都有美妙的特点: 节奏感,感情内涵,独特而权威的人声,甜美而不刺耳的高频,清晰度正好足够,富有三维立体感的稳定音场能超出喇叭的尺寸. 低频响应和动态绝不受妥协. 当需要时,MINI-DAC能展现出我觉得我的器材无法重播出来的动态范围.)
What a delight of a machine! No other piece of Hi-fi gear has ever brought me such listening pleasure as the Mini-DAC and never was I so reluctant to return a device that I reviewed. I have to. I don’t have the money right now. But to those who do, it must be obvious what I recommend.
(译: 多么令人赏心的一部机器! 没有其他HI-FI器件曾经给过我这么美妙的聆听乐趣. 我也从未曾如此不情愿归还一部借给我试听的机器. 然而我必须归还它,因为我手头没有足够的钱. 但对于那些有足够钱的人,很显然我会推荐它!)
[ 本帖最后由 小白 于 2007-12-18 17:43 编辑 ] |
|
提升卡
变色卡
发表于 2007-12-18 19:27:17
