Class A 和Class AB 的优缺点
Class A tube guitar amps. Everyone’sheard the term. It’s generally associated with higher-end amps in support of anamp maker’s claim that their product sounds “better”.I’ll leave the debate as to which isbetter to others. What I want to discuss is what Class A really means and, fromthe pet peeve perspective, to debunk many amp manufacturers’ claims that theirproducts are Class A when clearly they’re not! You may be surprised at how manyamp makers falsely claim Class A operation. So, let’s review, in practicalterms, what Class A really is and learn a simple rule of thumb you can use tospot operating class BS!There’s no denying that Class A ampshave different tonal characteristics when compared to the more common Class ABamps. However, as with anything related to tone, “better” is in the ear of thebeholder. There are plenty of butt kickin’ amps out there of both classes.What does “Class A operation” mean?Technically, it refers to where on a tube’s operating curve, it’s biased.That’s it. Bias a tube one way and it’s operating in Class A, change the biasand it’s in ClassAB.Of course, there are always technicaldetails that complicate things. In this case, the complicating detail is thattubes biased to operate in the Class A “zone” require a lower voltage supply.Otherwise, they’ll quickly fail. Enough tech stuff, no need to worry aboutthat. I mentioned it to avoid a misperception that you can simply take your ampto a tech for a 5-minute re-bias job and you’re in Class A land. Can’t happen.Fundamental changes to your Class A/B amp would be required to lower thevoltage and otherwise set it up for Class A operation. Back to regularprogramming!Fixed vs. cathode biasing is another“Class A” related misconception. Many believe that if an amp is cathode biasedit is Class A. Not true. An amp can be A or A/B and fixed or cathode biased.Again, it depends on where the tube is biased on its operating curve not how itis biased.Another factor in the myth is that if anamp has a “single-ended” power tube configuration it is Class A. Conversely, sothe myth goes, if an amp has a push-pull power tube configuration it is ClassA/B. Once again, the operating class of the amp is not defined by the power ampconfiguration. It is true that many (most?) single-ended amps are, in fact, ClassA. But, on its own “single-ended” does not define an amp’s operating class. Anamp can be Class A push-pull or Class A/B single-ended or vice versa.The technical difference betweensingle-ended and push-pull power amps are perhaps a topic for another article;I mention it here because they are common terms and often enter into the ClassA vs. Class A/B confusion.I mentioned above that Class A ampssound different from Class A/B amps. To review, Class A means the tubes areoperating in a different part of their operating zone as compared to Class A/B.Two important things happen as a result. First, tubes operating in Class Aproduce more even harmonic content. Second, they produce less power.Tubes biased to operate in Class A/Bproduce more odd order harmonics. Generally, even order harmonics sound morepleasing than odd. That’s why Class A and Class A/B sound different. However,as I mentioned earlier there are MANY GREAT sounding Class A/B amps. Don’t getunnecessarily biased toward Class A amps (amp builder’s humor – HAHA!).The fact that a Class A amp with thesame power tube configuration as a Class A/B amp produces less power leads usto the simple rule of thumb you can use to check whether an amp is really ClassA: just compare the power tube configuration to the claimed output power ratingof the amp.Here are the guidelines I use to tell ifan amp’s manufacturer doesn’t have their facts straight: Power TubeEL84
6V6
EL34, 6I62-Tubes
15 watts A/B
20* watts A/B
40 watts A/B4-Tubes
30 watts A/B
40 watts A/B
80 watts A/B *Some smaller Class A/B Fenders (e.g.early Princetons and Deluxes, etc.) that feature two 6V6s are rated around 15watts – later examples are in the more typical 20+ watt range.If the marketing hype shows output powernear or above these ratings and it says the amp is Class A – there’s somethingwrong! If the output power is a fair chunk lower, the amp is most probablyClass A. Simple!Next time you read a guitar mag have funby checking the tube configuration, power rating and operating class claims ofyour favorite amps. You may be surprised at what you find!
[ 本帖最后由 kldguitar 于 2012-10-24 18:36 编辑 ] 一类的电子管吉他放大器。everyone'sheard术语。它通常与高端的放大器，支持anamp制造商声称他们的产品的声音“更好”。
我把辩论哪些是别人。我想讨论的是一类真正的手段和视角，从忌讳，揭穿了许多与制造商声称货物是A级时显然他们不是！你会惊讶于如何manyamp者谎称类操作。所以，让我们回顾，在practicalterms，阶级是一个学会一个简单的经验法则，你可以使用tospot操作类学士学位！
不可否认，一类ampshave不同调性的特点相比，更常见的类abamps。然而，正如任何相关的语气，“更好”是在耳thebeholder。有很多的屁股踢了两类放大器。
什么是“类”的意思吗？技术上，它是指在一个管的工作曲线，这是偏颇的。偏压管的方法之一，它的运行级，改变biasand它在classab。
当然，总是有technicaldetails，复杂的东西。在这种情况下，复杂的细节是thattubes偏见在班级“区”需要较低的电压。否则，他们会很快失败。足够的高科技的东西，不必担心一下你人生的那个。我提到它避免误解，你只需将你的安普敦科技为5分钟re-bias工作和你在一级土地。不会发生根本变化。你的类/放大器将需要较低的电压，否则这类操作。回到regularprogramming！
固定与阴极偏置是另一个“类”相关的误解。许多人认为，如果一个放大器阴极是不真实的biasedit类。一个放大器可以是一个或/和固定或阴极偏颇。再次，这取决于管有偏见的对其运行曲线不怎样它偏向。
另一个因素是，如果anamp神话中有一个“单端”功率管配置有甲级。相反，这些神话，如果放大器推挽式功率管的配置是classa / B再次，经营类放大器是没有界定的权力ampconfiguration。这是真的，许多（最？）单端放大器，事实上，classa。但是，对自己的“单边”不定义一个放大器的操作类。anamp可以类推挽或甲、乙级单端或反之亦然。
技术上的差异，betweensingle-ended推挽式功率放大器，也许是另一篇文章的主题；在这里我提到它是因为他们共同的术语和经常进入到classa与甲、乙级混乱。
我上面提到的这类ampssound不同类/放大器。审查，一类的手段管areoperating一个不同的工作区相比类/ b.two重要事情的结果。第一，管类工作的aproduce甚至谐波含量。其次，他们所生产的低功率。
管有偏见的经营类/ bproduce更奇次谐波。一般来说，甚至谐波声音morepleasing奇。这就是为什么阶级和阶级/不同的声音。然而，正如我前面提到的有许多伟大的探空类/放大器。不getunnecessarily偏向类放大器（功放建设者的幽默–哈哈！）。
事实上，一个甲类功放具有相同的功率管的配置作为一个班/放大器产生较少导致我们简单的经验法则，你可以使用检查是否与真是classa：比较功率管的配置要求ratingof功率输出放大器。
这里的指引告诉我用如果放大器的厂商没有事实 这么翻译基本上伸马也看不懂。
Class AB和Class A
不完全是译文，仅提供的是大纲式的解说。１。 很多人认为A 类放大的功放音质较好，所以很多高端的功放都自称是A 类功放。２ 不能否认A 类功放的音质和常用的AB 类功放不同（如果你听不出来两者区别，那你就跟我一样没有音乐细胞了），但是否好听，这就是一个仁者见仁，智者见智的问题了。
３,一个管子工作在什么状态，决定于他的偏置点，偏置点不同，工作类型不同。
4 A 类放大， 偶次谐波分量比较多， AB 类放大，奇次谐波分量比较多，而偶次波声音要好悦耳一点。
5。 A 类功放一般功率要小于AB ( 如KLDguitar MC 36H 工作在AB 类，功率是36瓦， 而切换到A 类只能工作到18瓦）。所以，AB 类的headroom 要大一些。 二楼这机器翻译还不如不看呢 Power Tube 2-tubes 4-Tubes
EL84 15 watts A/B 30 watts A/B
6V6 20* watts A/B 40 watts A/B
EL34, 6I6 40 watts A/B 80 watts A/B
这是一般正常配置下，管子数量和功率对应表。另外，A 功放相对于AB类来说，管子寿命要短一些。
这机器人翻译的啥？ 一头雾水
A类 AB类各有所好，功率做大只能选AB类的 A类的功率浪费巨大，所谓的音色悦耳很多时候并不一定是你想要的，A类比较出名的是AC30，其实国内没多少人在用。
AB类推挽应该是比较科学的放大方式，效率高，两个管子轮流工作，管子寿命明显增加。FENDER，MARSHALL等等基本都是AB类。
回复 9楼 TCCUSTOM 的帖子
我想问一下 类似FENDER那种复刻款的箱子 比如59 BASS MAN DELUXE reverb黑脸这类的箱子是A类放大吧比如像新款的hot rod DELUXE 这类都是AB 我可以这样理解吗 原帖由 采菊花的小伙 于 2013-6-28 18:43 发表
我想问一下 类似FENDER那种复刻款的箱子 比如59 BASS MAN DELUXE reverb黑脸这类的箱子是A类放大吧
比如像新款的hot rod DELUXE 这类都是AB 我可以这样理解吗
都是AB 这种好文应该多发发。。。。
回复 11楼 guguang33 的帖子
长知识了啊 原来那些复刻款的 也是AB类 请问 ORANGE TH100 是AB 类的么 ? 二楼的头像 是可以的。 有一些小FENDER 比如57Champ 后级只有一根6V6 是不是A类呢 AB类应该是两根后级管子轮流工作吧？ 过后慢慢看。回复 16楼 采菊花的小伙 的帖子
一个管子只能是A类，另外，有一个要求是单端 （SE），单端由于没有反馈回路，所以音域要宽一些。 这篇老帖被选为精华，实在荣幸，找机会一定把他译出来，不然有点对不起大家对Class A 和Class AB的一些补述
通过不同艺术家的演奏，借以更好的描述Class A 和Class AB的 区别http://player.youku.com/player.php/sid/XNjQ0ODA5OTM2/v.swf
Player: Niels van der Steenhov
Country: Ducth
Class A
Player: Mark Harding
U.K
http://player.youku.com/player.php/sid/XNjgxMDQ1MzMy/v.swf
Class AB
Player: Mark Harding
U.K
http://player.youku.com/player.php/sid/XNjgxMDEyNDY4/v.swf
http://player.youku.com/player.php/sid/XNjc4NDU1MTI0/v.swf
player :不详 我也喜欢学习这类知识，谢谢楼主～～ 好像a类和ab类的差距没有大到不能接受嘛，我倒觉得还各有特点。 Though widely believed to be a class A amplifier, the AC30 is in fact class AB.
虽然被广泛的相信是CLASS A功放, AC30事实是CLASS AB类
这尼玛直接复制过来用软件翻译的东西也能精华。我也是醉了！ http://bbs.guitarschina.com/data/attachment/forum/201605/26/145131kixj05htoie4r070.jpg
欢迎扫描二维码，进入我们的微信群。 从楼主发的视听视频感觉我喜欢AB类，那么orange or15是什么类？怎么感觉60H的6L6管子好听呢？我的音箱求助贴http://bbs.guitarschina.com/forum.php?mod=viewthread&tid=2091068&extra=page%3D1%26filter%3Dauthor%26orderby%3Ddateline
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