英国和弦是HIFI圈热门品牌之一，旗下Choral系列解码更是以精巧时髦的饭盒造型，松香味共鸣感十足的英伦调音，高贵不贵的定位深入人心。

我入手两个月的DAVE，则是和弦今年才正式推出的旗舰解码。旗舰体现在哪里？首先是功能：自带耳机输出与数字前级。其次是数据：首次做到APX555无法测出任何底噪与谐波失真。最后是价格，与之前款型相比，定价几乎翻倍。








作为多面手的DAVE，不靠“堆料”。它的内部可谓简单，也可以说复杂，随着FPGA技术的不断发展，DAVE可以用十倍于Hugo的性能，去运转独家算法，不再受限于使用第三方DAC芯片，也没有传统Delta Sigma与R2R架构开关速率低的限制。DAVE，甚至连整机控制和字体显示都由同一片FPGA芯片计算，手写程序来完成。这样极度简化的机内线路，才有了前文提及的惊人指标。官方自信宣布DAVE的数字音量，即使用到最大程度的衰减，其信息量与透明度可以超越任何模拟前级。

论坛名人Romaz在试用Dave后，出掉了曾让他感动泪下的六分体天价音源。“As it has become clear to me that what is connected before the DAVE has become less important, what is connected after the DAVE has become even more important.”他点评DAVE，除了招牌的热情与鲜活，音场的纵深与高度（好似2ch音乐出杜比全景声的包围感）、与对前端的免疫才是核心提升。Dave之前用什么转盘和线不再关键，而之后的耳机与音箱系统，却怎么折腾都不过分。
我原先的系统，是美国BRICASTI M1解码、最新款ATC 50ASLT主动版音箱，配上原厂SCA-2前级。作为曾经的耳烧，也留了几副耳机用于夜晚聆听与较音参考。这是一套足够满足我听音需求的简单组合，其中的每个环节都无可取代。去掉前级改用解码直推，钢琴变得拖泥带水，气势全无。不同耳机，需要搭配不同级别的耳放和线……

和弦的“黑科技”宣传与多功能定位打动了我，第一批下定了DAVE解码，然而这些数据真能为我的系统带来跨级别的音质提升，亦或是可以简化我的组合搭配？必须耳听为实。

完美Timing

最初诱起我对DAVE兴趣的，是国外用家听感中所说的完美Timing，个人理解为类似英国茗的节奏感。高端茗cd机那充满韧劲的现场感正是我的最爱。相比M1解码的沉稳、内敛，DAVE带有更鲜活的中高频染色，明亮而圆润。强烈的纹理与瞬态，配合拿捏有度的起伏控制，毫无拖泥带水，和弦的钢琴与弦乐真是一绝。而音场完整性、密度与动态竟也再上一个台阶。用一个词难以概括DAVE的特色，它仿佛一张顶级数码相片，画面中的一切都活了起来，目不暇接的热情让人来不及思考，随波逐流，一时好听得不想关机。差点忘了，记得打开DAVE选项中的滤波再听！

“高保真”耳放

DAVE的耳机输出是个热门话题。在讨论区被拿去与众多高端耳放PK，传水准在Eddie Current Balancing Act管机或Simaudio Moon Neo 430HAD晶体管机之上。合适的耳机，则有HE-1000、Hd800s……从Hugo开始，和弦一体机的耳机输出，都用上Direct-to-DAC独有直通解码架构，不再需要额外的耳放线路，也足够推动各路顶级耳机。在耳机界，被玄乎的称之为直通音乐的最短途径（从耳朵到麦克风）。
在我听来，DAVE的耳机输出，甚至比接入音箱系统，更体现一些自身特点：那是一种透明度、力度、速度、控制力兼备的声音。第一次搭配T1 MK2耳机，我惊讶于ATC音箱的空间细节竟然比不上耳机，从未感受过如此强烈的现场气场与3D互动感。值得为DAVE找一副搭配素质出众又不缺低频衬托的耳机，感受和弦顶级调音的绝妙。

数字前级有惊喜

数字音量是如今的潮流，许多解码品牌，都宣称自己的音量控制，通过算法或模拟线路，可以替代高等级的前级。然而现实残酷，选择ATC SCA-2前级，是我对比过EAR、势必草等知名前级后的选择，较为适合我的房间环境与平衡度喜好，多年来无法被解码数字音量所取代。

DAVE第一次直连ATC 50ASLT，我是失望的。声音厚密，火气偏大，层次感有所损失。但我调整搭配后发现，之前的很多周边配件，都有过于浓厚有力的倾向。为了弥补房间声学也好，个人喜好也罢，现在变得多此一举了。直推的尝试一波三折，但最后的结果，是我决定卖掉ATC前级。前级能拉宽音场，低频的量感较多。而鲜活、透明、纵深感和层次感就是直推的强项，原先系统中显松散的钢琴左手段重现也变得流畅。和弦小饭盒直推一对大喇叭，如此违和的现代感组合！系统的性价比又提升了，可谓是意外之喜吧。

DSD也有“黑科技”

SACD被破解后，普及了几千张DSD数字音乐。DSD功能也成了这几年解码的必备卖点。我也曾为此买过一台纯DSD解码。然而静下心来，发现真正的好声音，并不在于格式，而是转盘与解码。好音源，即使播放CD与CDrip，一样出动态夸张、层次鲜明的好声音。之前的聆听，我选择的全部是CD与PCM规格音乐。
和弦近年的解码，数字输入范围都做得极广，从44 kHz到768 kHz，从DXD 到四倍 DSD支持，全都没有问题。值得一体的是，这次为了完美回放DSD，和弦为DAVE全新编写了两套独立的解码算法，充分发挥出新一代FPGA性能。需要DAVE选DSD模式并等待一秒，切换到专属的算法。声音之妙，找机会试下便知。即使不切换，在标准的PCM模式下，DAVE也是可以回放DSD音乐的。


前端与周边真的全免疫？

DAVE对前端转盘的宽容确实给我留下了挺深的印象，无论是接入林德曼CD兼网播、鱼大专机，甚至是BOSE蓝牙输入，都能出来圆润饱满的声音，但风格差别仍然明显。
我也测试了手边的一些配件：
USB线：随机线、Entreq挑战者、AIM UA3
两种墙插：381Au老款、EAGLE 8200
排插或电处：音乐丝带QB4 MK2（QED参考总线插381Au）、日本中村160w隔离牛等
电源线：随机线、Jorma、Stealth、Tiglon、分析家、NBS、Naim机线，Gotham 2.5平方DIY线等
对比后选择了：
DAVE直插Eagle 8200墙插、其他设备接入音乐丝带QB4 MK2。USB线选择了场面宽广的Entreq，随机线素质较弱，但也耐听。而电源线中，Stealth Straight的表情刻画、NBS Omega2的宁静饱满、Naim机线的低火气表现我都挺喜欢。为DAVE选择最合适好听的周边，值得！



想到DAVE包里一塞就可以走南闯北，直插耳机轻松愉快，FPGA也有无限潜能。突然发觉，未来的发烧之路似乎离不开和弦了！

Chord DAVE设计师Rob Watts论坛言论节选：

关于电源和噪音：

What people don't understand is that a DAC internally is a RF noise hell (and moreover is signal correlated too) - and this is several orders of magnitude more noisy than the noise you get from a properly designed PSU. That is where the effort goes into - the internal nodes in the DAC, where people don't see, appreciate or understand the difficulties.

大伙不了解，解码内部才是射频噪音的垃圾场——比从外部电源引入的噪音多几个数量级。这就是为什么我们在不断努力去改善解码的内部节点。而大伙看不到，也不能欣赏和理解这其中的难度。

关于DAVE的FPGA核心：

Dave has a single FPGA, with about ten times the capacity of Hugo's. I don't know where 4 came from, that would have been the DAC 64.
It controls everything, including the display, which means that apart from the USB decoder (which is not on Dave's ground as its galvanically isolated), there are no other digital processing devices. This way I get the lowest possible noise, with everything running from the crystal oscillator. That said, it was a pain creating my own font generator to drive the display.

DAVE内部只有一块FPGA，性能为HUGO的十倍。我不知道四块是谁说的，那是DAC64时代的设计。

FPGA控制一切，包括显示屏，这意味着除了USB接收（它不与DAVE共地，因为做了电气隔离），机器内没有任何其他的数字处理元件。这是为什么我做到了最低的噪音可能性，一切根据时钟运转。换句话说，为自己的显示屏设计字体合成器真心痛苦。

关于开关电源、线性电源：

I am sure there is some compromise in using a linear power supply - in fact I know there are compromises.

Perhaps I should explain.

When developing Hugo in 2012 I had to use switching regulators (battery life issues) rather than linear ones, as we all know linear regulators sound better don't they?

Funny thing was, in testing and listening, the switching regulators sounded a lot smoother and darker with much better sound-stage depth.

Also the DAC measured a lot better too, particularly with very small signals. I now know exactly why this happened, and why they sound better and exactly why they measure better within a DAC.

Moral of the tale? Don't make assumptions based on what you think is happening, do the work, do the measuring, and do the rigorous listening tests. Then you find out that things are not as simple as you think, and you find out that previous certainties were mere assumptions.

我可以确信的是，如果换上线性电源，那会是一种妥协——实际上，我知道有哪些妥协。

我来解释下。

12年我设计HUGO的时候，我不得不选用开关稳压（电池持续时间的原因）代替线性稳压，我们都知道线性稳压声音更好不是？

有意思的是，在测试和试听环节，我们发现开关稳压听起来更顺更黑，连带音场深度提升非常明显。

同时，解码测出来的指标也好多了，特别针对细微信号。我现在掌握了到底是什么环节，为什么解码内开关稳压声音更好、测试结果更好了。

寓意？别根据你认为会发生什么去臆想，去做，去测试，谨慎地试听实践。你会发现事情不像你想象的那么简单，然后发现很多先前确信的事，其实只是臆想。

关于耳机模式里的Crossfeed设定：
0 is no crossfeed; 1 is min, 3 is max.
As to cross-feed - I prefer 3, its closer to loudspeaker perspective.

关于耳放crossfeed补偿模式：0为无补偿，1最小，3最大。

我倾向3，最近接听音箱的感觉。

Now the problem is definitely not jitter from the source - my DAC's can tolerate 2uS of jitter and it will have zero difference to the measurements - also the USB is isochronous asynchronous so the timing comes from the DAC clock, so source jitter is not a problem.
So I looked into the issue of different SQ with sources and found two sources of error:
1. RF noise.
2. Correlated current noise.
So the solution to the above problems is galvanic isolation. This means that RF noise from the source can't get into Dave, and small correlated currents can't get in too. And this approach gave two benefits - much smoother sound quality, and a deeper soundstage.

Now with Dave I can no longer hear which source is connected, but before without the galvanic isolation it was easy to hear. Additionally, optical sounds almost identical to the USB, as optical is clearly galvanically isolated too.

关于USB链接不同电脑或数播音质不同：

我的解码可以容忍高达2uS的jitter，而测试结果并无不同。异步USB意味着时钟基于解码，所以音源Jitter不是个问题。

我觉得不同转盘音质不同，主要源于音源产生的两类干扰：射频噪音和相关电流噪音。

解决方式是做电气隔离，之前没有隔离的机器（Hugo等）能轻易听出音源差异。另外，光纤与USB的音质几乎等同，也是因为光纤显然能做到电隔离。（他曾说平衡数字线路是造成音质问题的原因之一，所以DAVE多达四组BNC数字输入，两组光纤输入，而只有一个AES口）。


网友问：为什么其他解码耳放一体机需要额外的耳放部分
为什么其他解码的模拟部分如此复杂：

Just a thought. Why do other DAC/headphone amps have amp sections when Hugo/Mojo get by without one, and many including Chord say it is more transparent? Have Chord got the patent for ampless amps :-)

A：Because they can't using chip based DAC's. Chip DAC's have two current outputs. So you need two I to V converters (amps) then a differential to single ended amp, then a headphone buffer to deliver the current. You also need a lot of analogue filtering wrapped around these amps. So why are normal DAC's so complex in the analogue domain? Two reasons:

因为（这种设计）不能使用基于芯片的解码。解码芯片有两路电流输出。所以需要两组IV转换（放大器），然后是差分转单端的放大器，然后是耳机缓冲。你还需要一堆模拟滤波围绕放大器（所以增加了干扰和底噪）。因此为啥普通解码模拟部分都那么复杂？有两种原因：

1. Silicon DAC's are horribly noisy, as the substrate and grounds are bouncing around due to switching activity. So to counter this, it is done differentially, which means the ground noise is cancelled. It also hides the problems of the reference circuitry, which can't be made with low enough impedance on silicon. This translates to more distortion, and crucially noise floor modulation.

1，解码硅片内部吵得很，因为基板和地会对开关活动造成不断反射。为了对抗这些，它会用到差分线路，因此地的噪音可以被消除。它也隐匿了参考线路中的问题，即是硅片上做不到足够低的内阻。这编译出更多失真、还有关键性的底噪调制。

2. Delta sigma converters run at low rates - best is at 12 MHz - this means that there is a lot of noise that must be aggressively filtered out in the analogue section. This also applies with R2R DAC's too as these have even worse problems due to the very slow switching speed.

2，Delta sigma转换器的速率很低——最高也不过12 MHz——这意味着许多噪音必须靠模拟环节的强力滤波来处理。这也适用于R2R解码，因为切换速率如此之慢，产生的问题只会更严重。

So to run with a single amp section you need the DAC to be single ended and to run the noise shapers at much higher rates to reduce your filtering requirements. Because the analogue section with Mojo is discrete, I can use extremely low impedance and low noise reference supplies - something that is impossible on silicon. This has the other benefit of eliminating noise floor modulation (actually there is a lot more to it than this as there are countless other sources of noise floor modulation in a DAC). To make the filtering easier, the pulse array noise shapers run at 104MHz - over an order of magnitude faster than normal. There are other benefits to running the noise shapers at 104MHz, principally the resolving power of the noise shaper. Now soundstage depth is determined by how accurately small signals are reproduced. The problem with noise shaping is that small signals get lost - any signal below the noise shaper noise floor is lost information. But by running the noise shaper at much faster rates you solve this problem too - indeed Mojo noise shapers exceed 200dB THD and noise digital performance - that's a thousand times more resolving power than high end DAC's.

要同单端放大部分一起工作，DAC必须是单端的，且整形滤波必须处于非常高的频率以减少滤波需求。因为Mojo内部的模拟部分是分立的，我可以使用极端低内阻和低噪音基准的产品——有些硅片完全做不到。另一个好处就是不再需要底噪调制（实际上需要做的远不止这些，解码内还有其他数不尽的底噪调制源）。为了让滤波更简单，脉波阵列噪音整形运行于104MHz——一个数量级地超越一般做法。运行在如此高的频率还有其他方面好处，尤其是噪音整形的分辨率。如今音场深度取决于小信号的还原准确程度。噪音整形产生的问题，就是小信号的损失——信号小于噪音整形本底噪音的就是损失的信息量。但通过把噪音整形运行在极高的速率，你也就解决了问题——实际上，Mojo的噪音整形能超越200dB THD，噪音数字水平——分辨率上成百上千倍地超越那些high end解码。

If I get time today I hope to publish noise floor modulation measurements showing Mojo has zero measured noise floor modulation. This level of performance does not happen on any other non pulse array DAC's at any price, and its the primary reason why Mojo sounds so smooth and musical.

如果我今天有时间，我希望能发一些底噪调制的测试数据来证明Mojo的零底噪调制。这种水平也没有任何价位的非脉波阵列解码可以做到。这也是为什么和弦可以做到如此平顺乐感。

其他帖子还有很多技术讨论，就不一一翻译了，有兴趣可以去原帖看。

http://www.head-fi.org/t/766517/chord-electronics-dave/2010

Rob解答网友提问，最佳解码耳放一体机大战三选一：南瓜HD，法国解码和DAVE？

So now we need a battle between the 3 pretenders for "Best DAC with a Headphone Out" :  NAGRA HD DAC, TotalDAC D1-Dual (or Mono) &  DAVE.  Who will win ?
Rob:
That depends on how one defines best - if best is defined as transparency and musicality then Dave will win easily. I am prepared to bet a brand new Dave against a bottle of Bollinger that Dave will win.
在于你定义最好的标准是什么——如果看重透明度和音乐性，DAVE轻松胜出。


另备注一下，平衡口因为加了短路保护，不能用来直连耳机。而四个BNC高速输出口，未来CHORD会推出配套的极简数字后级（用于高灵敏度音箱和高级耳机），已达到消除后级个性，系统音色即DAVE音色的目标。

ROB贴出的测试指标（转帖）：

真心不喜欢饭盒的外观

排骨年糕

没有架子看起来好一般啊，dave官方那个架子很帅

嗯，看刘总的介绍，对和弦这个品牌还是很有信心的。

还是对msb比较感冒

架子贵...用一段时间看看，再考虑买一个

chord的顶级解码不标配个架子也是过分了，又不是多大的东西，黑

我原来觉得这个架子是专门用来叠放在后级上而设计的...如果有一堆Chord设备，倒是还有专门的饭盒多层架子。

最老的HIFI杂志，英国HIFI NEWS最新评测：阴阳的两面：黑胶 pk 数码音乐，深度分析了两个独一无二的产品the Clearaudio Statement turntable and the technical triumph that is Chord's flagship DAVE DAC，DAVE和清澈黑胶系统都有拿到91% 分数，比之前评测的DCS Vivaldi分数高1%（还没看评测内容，不排除涉及到性价比因素）

A rare high score for Chord’s DAVE, but then this is no ordinary digital-to-analogue converter.
From the handcrafted quality of its casework to the sheer quantity of proprietary engineering within, this is a standard-setting product, and when you hear it in action all that hard work – and the price – is more than justified by a scintillating performance. From lab to listening room, this is an outstanding product.

网上有电子版杂志，下到了，有点意思，先去看看。