原帖由 manray 于 2009-9-19 21:05 发表 http://bbs.headphoneclub.com/images/common/back.gif
first walt都是pass给全频设计的。用f5需要高增益前级
斯必草就行了
F5不是说可以很好地驱动/控制低至2欧姆阻抗的机器吗？
啊，是我推荐的，不过能不能用在这个机器上要试一下，First Watt系列本身确实是给pass全频设计的，尤其是F1。F1是最合适全频喇叭的。但是我有F1，感觉上高效率喇叭即可，不是一定要全频喇叭的:)。这对喇叭的灵敏度有94db。。。不是一般的高。
至于F5的增益是15db，真的不算太高，但是nelson pass已经推荐给一般喇叭用了，不像F1-F4。
So far, First Watt has made a few different amplifiers: Very different amplifiers.
Quite a few people have asked me for a regular sort of amplifier, you know the kind you plug like any other, with some voltage gain and a real damping factor.
Amplifiers that have low distortion and noise, and will drive a 4 ohm load.
The last time people asked for that they got the Aleph J, which satisfied most of those requirements. Single-ended Class A, the Aleph J is an easy-going design which is happy driving 8 ohm loads with a warm, relaxed presentation.
By way of contrast, I present the F5 (taa-daa!), a push-pull Class A amplifier, utilizing JFETs and MOSFETs in a very simple two stage complementary circuit – a little bit like a complementary version of the Aleph J. But like all the other First Watt amps so far – this one is different.
In many ways, it’s an ordinary topology - the basic circuit is found in numerous preamp circuits and the odd power amplifier (Check out the Profet amp from Selectronics). But the F5 is the product of numerous decisions that set it apart.
It has very wide bandwidth, DC to > 500 KHz.
No capacitors anywhere in the circuit. (except in the power supply, of course!)
It has a high input impedance – 100 Kohms, and a high damping factor (~60)
The distortion is very low, between .001% and .005% at 1 watt.
It’s very quiet, about 60 microvolts or so.
It will drive a 2 ohm load without burping, and 1 ohm without misbehaving.
Did I mention that it sounds terrific?
So enjoy. In addition to the normal owner’s manual information, I have appended the original DIY F5 article which appeared in AudioXpress.
Nelson Pass 5/24/08
他自己说的可以推动1ohm的。。其实first watt的每一个型号都是相对独立的，在不同的设计下的探索。
不过还买得到吗？。。。
[ 本帖最后由 pig2man 于 2009-9-20 12:47 编辑 ]
原帖由 pig2man 于 2009-9-19 22:54 发表 http://bbs.headphoneclub.com/images/common/back.gif
啊，是我推荐的，不过能不能用在这个机器上要试一下，First Watt系列本身确实是给pass全频设计的，尤其是F1。F1是最合适全频喇叭的。但是我有F1，感觉上高效率喇叭即可，不是一定要全频喇叭的:)。这对喇叭的灵敏度有 ...
f5有diyer自己做的加强版，可以应对大多数的喇叭，但是肯定不包括威信这类阻抗特性特别复杂的喇叭。
不过f5作为一个后级的设计理念真的是很完美了，fw比较能体现pass的鬼才
哈哈，我手头没有F5，也不清楚它到底行不行，只是听人说过很不错。反正应该买不到原版了，只能自己diy了。。:lol
[ 本帖最后由 pig2man 于 2009-9-20 21:37 编辑 ]
