North Star Essensio

[Yeh捨]

恩 對阿最好有AYRE QB-9 WEISS DAC202,之類的,看看彼此的音色差異在哪?

重燒土砲管機 dac(友借)..有rca.aes/ebu 數位輸入..R/L rca輸出可否..:P

響法..見emu0404與其他二機之評比文..

[drunkenlife]

重燒土砲管機 dac(友借)..有rca.aes/ebu 數位輸入..R/L rca輸出可否..:P

好啊，雷爾斯有隻Esoteric UX1可以當轉盤，這個夠格吧？

[tvec]

我也是差不多1:30要離開，2:30前要回到土城

[doubletoplei]

期待下對比評測的結果...葉sir和drunkenlife大總結下USB DAC32, essensio, 以及QB-9的聽感對比哈,不勝感激

[drunkenlife]

感謝io8277與tvec二位攜帶Essensio及DAC32千里迢迢在雨天老遠跑到汐止來，
二部同廠牌二個級距的機種的表現，確實沒話說，高級機種在空間感、細節、細膩度上明顯勝出一籌，
但二部都明顯聽的出來jitter都不高，音像都相當穩定，一如預期async USB DAC會有的優點。

[Yeh捨]

async..原字 asynchronous 發音..ㄟ'辛可諾耳死.
譯為..非同期的..異步的.

可能不少網友對 async usb dac 還不太了解.能者可否簡說明一番..?

今天在下工程忙碌未赴參與..真是唆蕊.

[io8277]

感謝 drunkenlife,還有雷爾斯黃先生ˋ柯先生的招待.恩隔離變壓器真的不是蓋的讓聲音升級許多,另外雷爾斯的落地喇叭,再加上前後級的驅動下,表現真的不輸越點的PCM喇叭.

[drunkenlife]

async..原字 asynchronous 發音..ㄟ'辛可諾耳死.
譯為..非同期的..異步的.
可能不少網友對 async usb dac 還不太了解.能者可否簡說明一番..?

這篇裡 http://www.computeraudiophile.com/co...B-Audio-Primer

"In Adaptive mode the computer controls the audio transfer rate, and the USB device has to follow along updating the Master Clock (MCLK) every one millisecond. The USB bus runs at 12MHz, which is unrelated to the audio sample rate of any digital audio format (i.e. 44.1K requires a MCLK = 11.2896MHz). Therefore Adaptive Mode USB DACs must derive the critical master audio clock by use of a complex Frequency Synthesizer. Since the computer is handling many tasks at once, the timing of the USB audio transfers has variations. This leads to jitter in the derived clock." Says Wavelength Audio's Gordon Rankin.

也就是說，adaptive mode下，USB DAC由收到的資料量來合成clock，
而在async mode下，則是自己有一個產生clock的石英震盪子，
二者自然會有相當的精準度差異

哎，糟糕...還是漏了拿出io8277的CD...還擺在我的Mac裡...
地址給我吧，寄過去...

又，tvec，sampling rate必須用應用程式下的工具程式裡的 音訊 midi設定

[io8277]

=.= 是漏了哪一片??我沒注意到,請直接幫我寄到我店內的地址 謝謝.

[kevintran]

我個人覺得Asynchronous 和 Adaptive 都不能“保證”沒有jitter. Gordon Rankin當然是賣瓜的說瓜甜了.

聽一聽另一家之言
Quote from CEntrance DACport http://www.centrance.com/products/dacport/

Jitter Management - Debunking the Asynchronous Myth

Some manufacturers may lead you to believe that Asynchronous USB transfers are superior to Adaptive USB transfers. This no more true than saying that you "must" hold the fork in your left hand. If you know what you are doing, you will feed yourself with either hand.

The USB argument comes down to jitter management and goes as follows: In Asynchronous mode the device is the clock master. In Adaptive mode, the computer is the clock master. Either way works fine, if correct design principles are followed. Here is the tricky part that often gets omitted: No matter which side is the source of the clock (PC or DAC), the two devices are still connected by the USB cable and the digital data on that USB cable is always irregular because the computer is involved. Computers do many things at once and end up sending data over USB in irregular intervals, no matter who is the clock master on the bus. This irregularity causes jitter. So, there is no jitter-free solution, just like there is no dust-free house. Irregularity always creeps in and needs to be actively managed.

DACport jitter cleanup

Here is where the Asynchronous vs. Adaptive argument breaks down: In either of the two clocking schemes, jitter is present during transmission. It's inevitable and also ok, if it is properly cleaned up prior to the D/A conversion, where it matters most. Neither clocking scheme is superior and both are capable of performing well if you know how to reassemble the bits prior to the DAC. Now, how do you actualy do that? There are many ways, the oldest and simplest of which is buffering. Irregular data comes in, regular data goes out. The most important part is to make sure that samples leaving the buffer on the way to the DAC are clocked accurately. DACport employs JitterGuard™, a proprietary two-stage clock management system that does just that - cleans up the jitter on the USB bus so that samples are virtually jitter-free at the D/A conversion point. The result is a natural response, crisp definition, extra resolution and wide soundstage.

我兩家的東西都沒買（沒預算）.