เอามาฝากจากกระทู้ Ayre DX-5 ใน AVS Forum ที่ลุงเริ่มไว้ครับ
อันนี้ Charles Hansen มาตอบไว้มื่อวานเกี่ยวกับตัว DX-5 ครับ
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Q: [Quote:
Originally Posted by rtrautner
I own the CX-7 and QB-9 and would consider replacing both with the DX-5 but only if I can convince myself that all functions represent a significant upgrade.]
A: I usually have a grading scale with only three steps of difference:
Noticeable -- This means that the difference would be easily noticeable to a careful listener who is familiar with that system. If you are not a careful listener or not familiar with the system, you would probably notice a difference but possibly not.
Significant -- This means that the difference would be not only noticeable to almost anyone who listened to the system, but that the improvements were large enough that you would not want to go back. In fact you would feel deprived if you had to go back.
Dramatic -- This means that the difference would be instantly obvious to anyone who listened to the system, and furthermore everyone would agree that the improvement was quite large. Anyone who listened would feel completely let down upon returning to the old system.
I don't think it is possible to have a change greater that "dramatic". It is possible to have changes that are smaller than "noticeable". For example, I hear an improvement when I turn off the display of the C-5xeMP. But the difference is so small that I rarely bother to do so, even though it is on the remote handset. We might do it at trade shows to get that last little bit of an edge.
Compared to the CX-7 (assuming it is the latest CX-7eMP version) and QB-9, I would rate the following areas of improvement:
CD -- Significant. The C-5xeMP outperforms the CX-7eMP, and the DX-5 outperforms the C-5xeMP. After spending a week with the DX-5, it would probably take a month or more to go back to the CX-7eMP and forget about how good the DX-5 was.
SACD -- Dramatic. Currently you cannot play them. That is about as big a difference as it gets!
DVD-Audio -- Dramatic to Noticeable. Currently you cannot play DVD-Audio discs, so that again is a huge difference. However, it is possible to rip them to your computer and play them on your QB-9. The original QB-9 only went up to 96 kHz, while later models and all DX-5's go to 192 kHz. But even at the same sample rate, the DX-5 is noticeably better on computer sources (I'm getting ahead of myself).
DVD-Video -- Dramatic! Once again you cannot play these discs.
Blu-ray -- Dramatic! Only a blind man couldn't see the difference between the two players (literally!).
USB -- Noticeable. The 192 kHz capable USB receiver board is identical with later (or updated) models of the QB-9. However, the DAC chip is a more expensive model with twice the current output for a 6 dB increase in S/N ratio, the audio circuitry has some extra refinements, and the power supply is double-regulated, meaning that a regulator feeds another regulator which feeds the audio circuitry. Both sets of regulators are discrete, zero-feedback types. It's not a huge difference, but if you have been living with the QB-9 for a while, you will easily notice the improvement. If that is your main reason for upgrading, it's certainly not worth $10,000, but you won't have to strain your ears to hear the difference.
I think that covers everything.
Q: [Quote:
Originally Posted by rtrautner
The Stereophile review that found SQ of the USB DAC comparable to the CD player was not very reassuring-one would expect it to be significantly superior.]
A: I'm not sure why you would say that. The QB-9 is definitely a significant improvement over the original CX-7. However I would say that it is only somewhere between a noticeable and significant improvement over the CX-7eMP.
But the reason for this improvement is not because a hard drive is better than an optical drive or anything
that. It's just that we have developed a more dynamic and engaging sounding analog circuit for the QB-9. I would hope that we have learned a few tricks in the eight years since the CX-7 was developed!
Q: [Quote:
Originally Posted by rtrautner
I'd
to know how the USB DAC compares to SACD.]
A: There is absolutely no way to make that comparison in a fair manner. It would be
trying to compare an LP to CD. Of course they sound different. But why? The mastering process? The analog-to-digital conversion process? The replication process? The phono cartridge? The turntable isolation platform? The phono stage? The DAC?
There are simply too many variables. And similarly with SACD. The DX-5 allows the best comparison possible, as the DAC chip, analog circuitry, and power supplies are all identical for the two formats. But that still leaves the source and how it was made and mastered as two huge variables.
Q: [Quote:
Originally Posted by rtrautner
Has there been any attempt to make this comparison with the QB-9 or, say with the Berkeley, Weiss, dCS, etc? Is any planned in the near future?]
A: Both SoundStage and The Audio Beat will have online reviews of the DX-5 in the next few months. I have no idea how much they will focus on computer audio or what they will compare the unit to.
However, I think it is safe to say that both the QB-9 and the DX-5 belong in the top echelon of USB DACs and can withstand comparison with anything out there. (The QB-9 just won the DAC of the Year award from Hi-Fi+ in the UK.) But what really sets the DX-5 apart is that this is the first time that anyone has made one single component that can be used for all of your digital audio and video. It will play any type of audio optical disc, any type of video optical disc, and it will also give world-class service as a music server along with your computer. So if you want rid your system of all of those boxes and all of that clutter, there really isn't any other choice. And considering what it offers, I believe it to be more than a fair value.
But it is your money and your system, and only you can decide if that is true for you. If you don't plan on watching any movies and/or listening to a lot of SACDs, then the improvement over what you have already may not be worth the added expense. The DX-5 is unquestionably better, but what you have already makes compelling sounding music. However, I'd rather spend money on a DX-5 than (say) a new car. It will hold its value longer, provide more pleasure, and require less maintenance. But it won't impress your neighbors....
