review33.com: 影音天地: 膽機同石機的輸出火數

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[#1] 膽機同石機的輸出火數各C Hing 膽機的輸出火數一般都係由幾火到百幾火石機的輸出火數一般都係由百幾火到千幾火幾千火請問兩者的火數"W"是否同一意思呢.........? 有無實際對比率呢.............? Thanks		ctscts888 正式會員 116.xxx.xxx.239	2011-03-23 16:41

[#2] 膽機同石機的輸出火數
＞請問兩者的火數"W"是否同一意思呢.........?

Their power was measured under the same Ohm's law. It is much more difficult to make high power tube amps. Some sales (or even so called "high-hands") would tell you "tube amp watt" is different from "solid state amp watt". Well, that is talk from someone who treat hifi as hocus-pocus and conveniently ignore the real science.

Actually, one has to understand what the power specs really means before one can draw a scientific conclusion:

(1) the power measurement (Watts) is pretty much well defined as "no. of watts at certain load impedance". However, many people for some reasons, ignored the "at certain load impedance part". That is why often people would find a 100W AV amp being less powerful than a, say, 100W stereo amp. The reason is that they ignored the little words "at 6 ohm" commonly used in AV amp specs while typical stereo amp would be measured at 8 ohms load.

(2) although some amps may have a high power measurement at 8 ohms, they may not be able to pump out any extra current at lower impedance.The actual impedance of a typical speaker is not constant and varies over it's range of frequency response. The impedance of some speakers may dip as low as 4 or even 2 ohms at certain frequency, amps cannot deliver the required current at those dips or, God forbid, starts falling apart at those dips would perform much worst than more capable amps with the same power specs.

(3) the clipping characteristics - typical tube amps clip much softer at power peaks than solid state amps, and such characteristic would enable the softer clipping amp to play at a higher volume with less noticeable distortion. The legendary NAD 3020 amp had a soft clipping circuit built-in and that was one of the reason why the little 20W amp was so popular back then.

The above are some of the major reasons why tube amps can play louder than similar power solid state amp.

Simply put, the power specification of an amp does not tell the whole story. One has to consider other factors such as power bandwidth, current capability, load stability ... to understand how well an amp would perform.

最後修改時間: 2011-03-23 22:34:54

olddude

正式會員
218.xxx.xxx.165

2011-03-23 22:25

[#3] 膽機同石機的輸出火數
請問有無中文呀, 唔太明....
Thanks

ctscts888

正式會員
116.xxx.xxx.239

2011-03-25 13:04

[#4] 膽機同石機的輸出火數
olddude will be happy to give u english lessons provided u pay a tuition fee

he has written in very simple english and any secondary school student can comprehend

did u go to school in hk?

最後修改時間: 2011-03-25 13:18:06

cpu8088

正式會員
115.xxx.xxx.214

2011-03-25 13:17

[#5] 膽機同石機的輸出火數
Watt 數 = 女人三圍 / 高度/ 體重
客觀測量數字一樣, 但實際效果會有差異, 因為因受很多測量條件影, 而每間廠都就往自己做

nickmanwoo

正式會員
61.xxx.xxx.158

2011-03-26 13:00

[#6] 膽機同石機的輸出火數
http://translate.google.com/?sl=en&tl=zh-TW#

他們的力量，在同一測量歐姆定律。這是更困難的，高功率管放大器。一些銷售（甚至是所謂的“高手”）會告訴你“管放瓦”是不同於“固態放大器瓦”。嗯，這是說話的人誰把音響作為騙人 - pocus方便忽略了真正的科學。

其實，人們必須明白電源規格的真正含義才可以得出的科學結論：

（1）功率測量（瓦）是幾乎正確地解釋為“沒有。瓦在某些負載阻抗”。然而，許多人由於種種原因，忽略了“在某些負載阻抗的一部分。”這就是為什麼人們往往會發現一個 100W的AV功放是不是那麼強大，例如，100W的立體聲放大器。原因是他們忽視了小字“6歐姆”中常用的AV功放規格雖然典型的立體聲放大器將在8歐姆負載測量。

（2）雖然有些放大器可能有一個高功率的測量 8歐姆，他們未必能夠泵出任何額外的電流較低 impedance.The實際阻抗的揚聲器是一個典型的不恆定和變化在它的範圍的頻率響應。阻抗的一些人可能下降低至4或什至2歐姆在一定的頻率，電流不能提供所需的電流在這些凹陷或上帝保佑，開始分崩離析那些逢低會表現更差於更強大的放大器，同樣電源規格。

（3）剪輯特點 - 典型的剪輯非常柔和管放大器在功率峰值比固態放大器，而這些特點將使柔和剪裁放大器來發揮出較高的體積不太明顯失真。傳說中的輔酶三千〇二十〇安培了軟限幅電路內置的，這就是原因之一，小20W的放大器是如此受歡迎當時的情況。

以上是一些主要的原因管放大器可以起到類似的聲音比功率固態放大器。

簡單地說，功率規格的放大器並不能說明整個故事。人們必須考慮其他因素，如功率帶寬，電流能力，負載穩定度...了解如何將履行好一放。

racewong

正式會員
58.xxx.xxx.33

2011-03-26 13:17

[#7] 膽機同石機的輸出火數
I believe people should ask about the loudness... the db instead the max Watt numbers

But it is very difficult to be fair to comment the loudness on various device.

With different loudspeaker, the loudness is different with 4ohm or 8 ohm speaker even connected with the same amp

May be it is the point that the number of watt is used so popularly for expressing the power of a amp and the capability of a loudspeaker

rd3

正式會員
202.xxx.xxx.5

2011-03-26 15:13

[#8] 膽機同石機的輸出火數
電壓=電流x電阻火數=電壓x電流
v= a x R w= v x a
若 R=8
石機有10w推喇叭假設電壓10v 那麽10v/8=1.25amp 因此石機的火牛要用到2-6倍瓦數才能應付一歐母阻擴，亦即是火牛要有能力提供足夠多amp比後級才能應付而且對功率管亦相對要求有更高的電流能力否則會燒機燒喇叭，這就是為甚麼一些高價後級要用大水塘再加大牛再加大量原子粒而一般石機火牛都在輸出100v內，因此家用擴音機不能用在會塲擴播上，因為一般洒店系統石機是有120v輸出再用牛降壓，所以只須50w就足夠。
而胆機後級電壓由數百伏甚至上千伏要用輸出牛來作輸出假設同樣10w 10v/8=1.25amp 而當喇叭隨聲音改變阻值時對整個後級來說只有很少影嚮所以在大多數情況下輸出比較穩定。因此會使人覺得胆機比較好力。這只是個人想法勿插

最後修改時間: 2011-07-08 12:38:19

kengchu

正式會員
182.xxx.xxx.13

2011-07-08 12:22

[#9] 膽機同石機的輸出火數
膽機同石機兩者的火數 "W" 是同一意思.

10 瓦就係 10 瓦，唔理你係膽機定係石機都一樣。
只係膽機會 soft clipping.................

打字太慢，唔講太多啦。
去搵下電子工程嘅書 (唔係吹水雜誌) 會講得好清楚。

parker75

正式會員
210.xxx.xxx.156

2011-07-08 12:55

[#10] 膽機同石機的輸出火數
kengchu兄，

唔知幾十年之前戲院通常係用幾多瓦輸出嘅擴音器推啲大大部嘅揚聲器 (好似 A2 果啲)???