严重中毒First Watt f1j
让代理找了一些日子，终于找到了。多谢杨版、蓝色狮子和PRIINCE99几位兄弟。因为机器是110V的，已经让代理那边联系NELSON更换为220V的。另外PRINCE老兄特意提醒牛需要额外加固。
借用个图YY一下
http://pic8.audiogon.com/i/c/f/1315233448.jpg
http://pic8.audiogon.com/i/c/f/1315233449.jpg
最初的1瓦最甜美！http://www.hdavchina.com/attachments/2008/11/17/2_2008111710512779Egy.jpghttp://www.hdavchina.com/attachments/2008/11/17/2_200811171051278wYxy.jpgPass Labs的创办人Nelson Pass现已退出实际设计经营，改当顾问了，在该公司的网页上，除了Pass :abs的量产品之外，我们还可以看到一个Pass DIY区块，以及另一个“First Watt”区块，这才是Nelson Pass最喜欢的工作。
DIY顾名思义，是由Nelson Pass提供构思与线路设计，欢迎所有人都一起参与，你可以用及其简单廉价的组件来制作，也可以不惜血本的精工打造，访问http://www.passdiy.com/default.html上有很多图片可供参考。Nelson Pass始终受到音响业界与发烧友的尊敬，不仅是他制作最高品质的功放，还包括无私的分享，以更高的理想推动音响线路的进化。Nelson Pass还没有进入音响业界工作前，他早已是DIY音响杂志《Audio Electronics》的撰稿人，发表许多创意线路，而许多DIY迷津津乐道的“禅”（Zen），就是Nelson Pass的杰作，在公布线路细节之后，吸引许多好手加入线路最佳化的修改意见，也让“禅”的线路不断精进。
Nelson Pass自己成为DIY圈子里的意见领袖，只要是非商业性的应用，他都欢迎音响爱好者善用他所公布的线路资料，制作出自己心目中最好的功放。而First Watt号称“直通Nelson Pass的厨房”，标榜由Nelson Pass限量制作的小功率高品质功放，他认为“音乐的第一瓦最重要。”在First Watt网站上销售的产品，设计的初衷都紧紧扣着这句话。网站上说明，所有First Watt的产品在销售周期结束以后，线路详情全部会上传到Pass DIY公开，让DIY族群可以非营利使用（注：First Watt并不是Pass的子公司，但设计者一样是Nelson Pass）。我们从图片中可以发现，First Watt的功放由里到外都简单到极点，以F5后级为例，利用JFET与 MOSFET构成二级放大的推挽式甲类放大，频率响应DC-500 kHz，声音路径上没有任何电容器，失真率仅有0.01，非常安静又有良好阻尼系数，所以不必担心有多少瓦数，音质的醇美才是Nelson Pass最关心的。
http://img.photobucket.com/albums/v389/MrSneis/DSC_0015.jpg
http://img.photobucket.com/albums/v389/MrSneis/DSC_0004-1.jpg
http://img.photobucket.com/albums/v389/MrSneis/DSC_0013-1.jpg
http://img.photobucket.com/albums/v389/MrSneis/DSC_0012-2.jpg
http://www.6moons.com/audioreviews/firstwatt3/2.jpg
[ 本帖最后由 davidxtb 于 2012-6-4 13:53 编辑 ] 款已经付了
又一个财务窟窿就此形成 和我听过的那个F1有啥区别？ 关注 First Watt的东西都适合KK吗？ 这大铁块看起来很帅 是jeft的管子么？ 熊大米人啊！线已经够毒！又升级二房！
到时蹭听;P 顶:lol :lol 这个是F1J，是升级版
Th F1J is an update to the F1 where the two gain Mosfet transistors have been replaced by new state-of-the-art power Jfet devices. In addition, there have been changes to several resistor values and removal of the input zener protection diodes. As with the F1, the simplified circuit of the F1J looks like this:
http://www.firstwatt.com/graphics/f1jsimp.jpg
The reason for bothering with this modification is very simple –better performance from faster, lower distortion parts. The new Silicon Carbide (SiC) Jfet transistors from SemiSouth are better in several ways. Here is a distortion vs power comparison between the original F1 and the F1J in the low to midband range where you see the newer parts have less than half the distortion:
http://www.firstwatt.com/graphics/f1jdamp.bmp
The difference is even more dramatic when we compare the distortion at 20 KHz:
http://www.firstwatt.com/graphics/f1jdamp20.bmp
We can also see this difference at a fixed wattage vs frequency:
http://www.firstwatt.com/graphics/f1jdfreqbal.bmp
TheF1 has always favored balanced input operation over single-ended input, but the characteristics of the Jfets help to narrow the gap between the two. As a result the improvement is even more dramatic between the F1 and F1J when operated single-ended:
http://www.firstwatt.com/graphics/f1jdfreqse.bmp
Notingthe improved performance for distortion at high frequencies, it is not surprising that the F1J also has more extended bandwidth as seen below:
http://www.firstwatt.com/graphics/f1jresp.bmp
You may notice that the F1J also has approximately 1.5 dB more gain. This is because the Jfets have a higher transconductance figure that the original Mosfets.
There is another factor as well, which is that the F1J has a lower input impedance than the F1- approximately 30 Kohm balanced and 15 Kohmsingle-ended. The modifications that help achieve this bandwidth take advantage of lower impedances, so the F1J is recommended for use with preamps with ordinary to low output resistance – tube preamps without cathode followers will work but will not reap as much benefit at high frequencies.
Thiscaveat aside, the F1J delivers a dramatic improvement in current-source amplification. I have often ventured the opinion that improvements in measured performance in simple Class Acircuits (particularly with no feedback) usually have the best correlation between what you measure and what you hear, and the F1J bears this out. I think it sounds about twice as good, and Ifeel certain that you will experience the same remarkable improvements.
The period for factories updates has elapsed, so at this time you are on your own. Here is the schematic (and some instructions) for the DIYers.Refer to the original documentation for original schematics and locations of components on the pc boards
http://www.firstwatt.com/graphics/F1J%20SCH.gif
[ 本帖最后由 davidxtb 于 2012-1-21 11:56 编辑 ] 兔大终于要入这个了，到时候比一下和rkv的听感啊，上次聚会您停lebencs300推kk了吗？感觉如何，想入手这个呢。 哗···羡慕:victory: 玩好KK容易
但是戴好KK实在是难度太高 只能放弃 我怎么感觉戴KK比戴800还舒服，800戴久了还是感觉夹头，KK佩戴会好很多吧！
