Some general information and things that may have been forgotten. 一些关于电子管吉他音箱的常识渐渐被人们遗忘了。
As we enter the 21st century knowledge from the 50's and 60's becomes more distant and obscure. 步入21世纪，那些1950年代和1960年代的知识渐渐远去和模糊。
Often we don't know exactly how things such as tube amplifiers were designed to work, causing a bit of confusion in both terms and function. 我们大多数人不清楚电子管放大器是如何设计出来的，与之相关的专用术语及其功能也变得混淆。
Maybe this simple page will make it clearer. 我希望通过这几页简单的叙述，能够把它讲的清楚。
Volume Controls. 音量旋钮
The volume control isn't a "gas pedal," the numbers are not a measurement of how much power is being used. 音量旋钮并不是音箱的“油门”，上面的刻度数字也不代表实际的功率输出。
That is, on a 100 watt amp, 5 is not 50 watts. 比如说一个100瓦的音箱，音量打到刻度5 ，并不代表此时输出功率是50瓦。
In general, Fender and Marshall amps all begin to "break up" or distort just above four. 一般来说，Fender 和 Marshall 的音箱在刻度4以上开始逐渐破碎，或者说开始失真。
The amp is putting out its full clean power at about three and a half. 音箱在刻度3.5左右达到清音程度的最大音量。
Early catalogs will bear this fact out. 你在调节其他旋钮的时候，必须时刻牢记这一点。
Why have the knob go to 10 then? 那么为什么所有音量旋钮的最大刻度都是10 呢？
Owners were expected to know about amplifiers and be aware that you couldn't turn it all the way up and expect a clean sound. 使用吉他音箱的人都应该清楚一点，你不能指望把旋钮都开到最大的时候，还可以得到清音的音色。
The instructions given were "if you notice distortion turn the volume down." 一个基本的指导原则就是：当你发现已经产生失真了，就应该调低音量旋钮。
The other reason for the wide range on the volume control was because guitars have an extremely wide range of output levels. 另外一个必须给音量旋钮这么大调节空间的原因是：吉他本身的信号输出范围其实是非常大的。
A Les Paul has about four times the output of a Telecaster and about six times the output of a Rickenbacker. 一把Les Paul的输出信号是Telecaster 的四倍，并且是 Rickenbacker 的六倍。
The manufacturers wanted to have their amp put out the full RMS power with any guitar. 制造商当然应该考虑到，他们设计制造的音箱应该能够适应各种类型的电吉他信号。
Master Volume Controls. 主音量Master 旋钮
Again, these are not gas pedals and not calibrated (5 isn't half power.) 同样的，这个旋钮也不是“油门” ，刻度数字也不是精确的（刻度5并不是输出一半功率）。
Master volumes were added to the amp designs in the mid to late 60's. 直到1960年代的中期，才在吉他音箱上首次出现主音量Master旋钮。
The idea was to be able to turn the preamp (the regular volume) up causing distortion，and then turn the actual volume of the amplifier down with the master volume so the distorted tones were available at a reasonable overall volume. 设置这个旋钮的目的是：增大前级的放大能力直到产生失真，然后使用Master旋钮把总体音量降低到合理的水平。
But master volumes don't work exactly like that as they are still within the amplifiers preamp circuit (and aren't controlling the final sound to the speakers.) 但是Master旋钮仍然属于前置放大级的范畴，所以它的表现并不完全跟前面叙述的一致（他们并不是直接控制扬声器）
Turning a master volume down causes some degree of distortion no matter where the regular volume is set. 不论音量旋钮在哪个位置，降低Master旋钮都会导致失真度在一定程度上略有下降。
If you want your amp to be as clean as possible, turn the master volume all the way up to 10. 如果你想得到最大音量的清音音色，Master旋钮必须开到最大刻度10
For clean tone - Turn the master all the way up, turn the regular volume down.
为了得到清音音色，你应该开大Master旋钮，而降低音量旋钮。
For distorted tones - Turn the master down, turn the regular volume up. 为了得到失真音色，你应该降低Master旋钮，而打开音量旋钮。
There are hundreds of combinations of master volume and regular volume. 这两个旋钮的组合方式有几百种，慢慢试吧。
Tone control circuits. 音调控制旋钮
Fender and Marshall amps share the same basic tone circuit. 芬达和马勺的音调控制电路基本原理是一致的。
This is not an active circuit and the controls are not "notch filters." 他们都使用了被动式电路，也就是所谓的“带阻”式滤波电路。
That is, they are not really tone controls that select a specific frequency response and boost or cut it. 这就是说，他们并不是选取某一部分频率，主动把它增强。
The treble control is more of a "mixer" between high frequencies and low frequencies than a treble control - it has a great deal of gain available. 高音旋钮其实并不是仅仅增强高频部分，它更像是一个高频与低频的混合器——它具有很大的增益调节空间。
Midrange controls are actually tone circuit gain controls that, within the circuit design, appear to boost midrange. 而中音旋钮则更像一个中频推进器，从电路设计角度来说，它的确是一个中频增益控制旋钮。
The amps can become muddy sounding with all the tone controls at 10. 在所有音调旋钮都打到10的位置的时候，声音会变得异常的发闷。
It's a good idea to evaluate the tone of the amp as you hear it instead of trying to duplicate some settings you've read in a magazine. 一边听声音一边调节音调旋钮的方式，比你试图直接从吉他杂志上复制那些设置参数更重要。
In general, any list of "settings" is very vague and inaccurate 一般来说，这些所谓的设置参数其实都很不准确
and would only apply to one person's playing technique with one particular guitar, plugged into a specific amplifier, with an individual speaker, in the same exact room - you can see - pretty inaccurate to your playing conditions. 你使用的吉他、特定的音箱、特定的扬声器、你的房间以及你的演奏方式，其实都会影响到最终得到的声音。
Boost Circuits used on Torres Amps. 推进旋钮（Torres 音箱）
Midrange boost. 中频推进旋
It increase gain, midrange and sustain. 它可以改变增益、中频响应以及延音。
It works best with the treble control turned up to 6 or higher and is not active at all with the treble below 4. 只有在高频旋钮大于6的时候它才起作用，如果高频旋钮小于4 则完全失效。
Gain Boost. 增益推进旋钮
It increase gain, bass and overdrive. 它会改变增益，低频响应以及失真度。
It gets its effect by deactivating part of the tone control circuit. 音调控制电路部分失效的时候，这个旋钮才变得比较有用。
When the gain boost is on, the tone controls are not as effective.当增益推进旋钮被激活的时候，音调旋钮则会失效。
Bright switch. 明亮音色开关
The standard guitar amp bright switch works if the volume is turned down a bit. 只有在音量旋钮降低的时候，这个切换开关才显得有用。
If the volume is at 10 the bright switch is out of the circuit. 当音量旋钮开到最大的时候，这个开关完全被旁路，没有效果。
General information for all tube amps. 关于电子管音箱的一些常识。
Most of the used tube amps we are using today were built quite a long while ago, 15 to 30 years. 很多我们正在使用的旧电子管音箱已经有15到30年的历史了。
At that time everyone knew a bit about tubes because everything used them. 那个时代的人多少了解一些电子管的知识，因为他们当时只有电子管可以用。
Now, we are pretty much in the dark about the whole thing, and the Guitar Magazine's "Tube Secrets" articles don't help much. 而当今的我们，则对电子管知之甚少，而且吉他杂志上的“电子管解密”之类的文章也没什么用处。
Tube amplifiers need to have a speaker connected all the time. 电子管功放需要随时有扬声器负载连接在输出端。
This goes for any tube amp, anytime. 这一点对任何类型的电子管功放都一样。
Even if you amp has a line-out, you still need speakers connected. 即使你的音箱有Line Out 端口，也仍然需要一直连接着扬声器负载。
Otherwise it will burn up the tubes and destroy the output transformer. 否则会烧毁电子管，甚至有时会击穿输出变压器。
Some very small tube amps have a headphone jack built in. 有些小型的电子管音箱会有耳机插口。
Usually these amps have a "speaker load" resistor switched in by plugging into the jack. 通常，在插入耳机以后，插座上的开关会把扬声器切换到一个负载电阻上面。
Read the amp instructions. 你应该仔细阅读音箱的说明书。
Note: without very expensive parts, this isn't practical at power levels above 6 - 8 watts. 注意：如果没有昂贵的元件，在6至8瓦以上是无法做到这一点的
Tubes are made of Glass. 通常电子管都是玻璃制作的。
Sure, no problem. 这当然没有什么问题。
But we forget sometimes and toss the amps around in the truck or back of the car. 但是有的时候我们会忘记这一点，直接把音箱往卡车后备箱里面一扔了事。
Its amazing how much they can stand, but you should be aware - glass breaks. 它们的坚固令人惊讶，但是你还是应该小心一些才对，毕竟玻璃是易碎的。
And once a tube is broken, it loses its vacuum and won't work anymore. 一旦玻璃破裂，里面就不再是真空了，电子管也就无法继续正常使用。
Usually the tube will turn white when it loses the vacuum. 通常在电子管破裂漏气以后，你会看见玻璃内部发白。
Discard "white tubes", they will never be any good 你应该把白色的管子换掉，因为他们肯定是坏的。
Tubes Don't live forever. 电子管的寿命是有限的。
One of the main reasons the "mainstream" world left tubes behind is the fact that they are temperamental. 主流音响界抛弃电子管的原因之一就是因为它们的寿命有限。
A brand new tube can last 20 years or 20 minutes and paying a high price for them doesn't really eliminate this. 一支全新的电子管可以使用20年，但是也可能20分钟就失效了，糟糕的是即使你花更高的价钱也并不会改变这一点。
It is a good idea to have spare tubes on hand. 最好的办法是随时备用一套电子管。
Buying matched power tubes will ensure that they have been tested and are good tubes, but it doesn't provide any kind of "any and all conditions" warranty. 购买已经配对的电子管可以保障它们是完好并且经过测试的，但是这也并不能为你提供“任何条件下的”担保。
New Old Stock (NOS) tubes 什么是NOS电子管？
New Old Stock tubes made in America can be very good, but are subject to the same temperamental nature of any item made of glass.崭新库存NOS电子管都是美国造的，质量非常好，但是毕竟它们是玻璃做的，有着所有的玻璃制品一样的弱点。
Almost all the tubes come from Russia, China and Eastern Europe. 现在市场上的电子管几乎全部来自俄罗斯、中国以及东欧。
The old folk-type statement "I just got them so they have to be good" is not valid no matter what brand or who you got the tubes from. 那种“我刚买回来的管子肯定是好的”想法肯定是行不通的，不管是什么牌子的电子管，也不管你是从谁手里买来的电子管。
The tubes being "lit up" does not absolutely mean they are good 电子管能够点亮，并不代表它们就是完好的。
12AX7 tubes. 前级管12AX7
Many tubes had different names in the past. 很多型号的电子管在过去有其他的名字。
The distinctions have evaporated and some tubes with several names are all the same tube now. 有些型号演化成为同一种管子，它们之间的区别逐渐消失。
Most common is the standard 12AX7 preamp tube. 目前最常见的前级电子管型号是12AX7
It has quite a few names. 它也有好几个名字
7025 (industrial equivalent) and ECC83 (British part number.) 它在英国的名字是ECC83，而工业用名称为7025
They used to be different, now they are the same tube. 它们曾经是有区别的，但是目前已经是同一种电子管了。
50's and 60's Fenders specify a mix of 12AX7 and 7025 tubes. 在1950至1960年代制造的Fender音箱都是12AX7和7025混用的
You can replace them all with 12AX7 tubes. 你完全可以直接把它们用全新的12AX7代替
What's a "standby switch?" 什么是Standby开关？
Fenders, Marshalls, Traynors, Boogie's all have one. 大多数吉他音箱都有一个STD开关。
Its purpose is to put the amp on idle while you take a break. 它的目的是，在你暂时休息的时候，使音箱暂时处于待机状态。
The tubes have a filament that has to be heated up in order for the tube to work. 此时电子管灯丝会一直保持热度，以保障你随时开机使用。
Heating the filament is why the amp has to "warm up."烧热电子管灯丝需要时间，因此音箱使用之前需要“热机”
The standby switch leaves the filament heated up, and turns off the power and preamp stages. 如果有Standby开关的话，就可以在关闭前级、后级放大电路的情况下，安心地等待灯丝慢慢烧热。
You can flip the standby switch off after a break and play right away. 你还可以在排练、演出的休息空挡时间关闭Standby开关，让音箱也暂时休息一会。
This extends tube life, as the filament doesn't have to be reheated every 45 minutes. 这样做可以有效延长电子管寿命，因为关机以后，45分钟之内电子管灯丝不应该被重新加热。
For a short break in the bar or club, put it on standby. 在排练、演出的空挡时间应该使用Standby暂停。
But, if you and the other guys in the band are going away - turn all the amps completely off. 不过如果你们演出完打算离开，则应该把音箱电源完全关闭。
A tube can go bad at any time. 电子管在任何时候都有可能出问题。
If the amp is on standby when the tube shorts out, you may have some damage. 如果音箱一直处于Standby状态，而电子管又坏了，那么你的音箱电路会因此受到损伤。
Only use the Standby switch when you are still around the amp. 所以你应该在有人随时需要用音箱的时候，使用Standby功能。
When you first turn the amp on, turn on the on-off switch, but leave it on standby for about 2 minutes. 你打开电子管音箱的时候，先打开总电源开关，但是Standby开关要处于关闭状态，并保持两分钟以上
This allows the filaments to heat up and be working right before you start playing. 这样就能使灯丝充分烧热，随时准备你开机演奏了。
Technology upgrades. Older amps. 老旧音箱的升级
When we work on older amps there are some parts that are becoming increasingly defective. 我们使用一些老旧音箱时，还发现他的某些部分已经严重退化。
The amplifier's power supply has "filter capacitors." 尤其是电源的滤波电容。
If the amp is over 22 years old and hasn't been serviced we will, most likely, have to replace the filter capacitors in the amp. 如果音箱已经达到22岁高龄，平时又没有良好的养护，那么它们大多都需要更换滤波电容。
What's bias? 什么是偏置？
Well, I won't go into all the voltage potential, reverse grid bias etc. 好吧，我不打算在上这里深入讲解什么是反偏负栅压。
mumbo jumbo. 那些知识对音箱使用者来说意义不大。
But be aware that the amp has an adjustment that has to be made with different tubes, and as tubes wear out. 不过我们应该知道，使用不同的后级管，以及随着后级管的损耗，音箱电路需要调整偏置电压以适应它的变化，
Anytime you change the power tubes the bias should be adjusted or at least looked at. 更换新的后级电子管以后，你必须重新调节偏置电压。
Again, no matter what brand etc. 重申一次，这跟你使用什么牌子的电子管无关。
The Bias is a negative voltage fed to the tubes. 偏置电压是加载到电子管栅极的一个负直流电压。
It makes them work right, and sound right. 只有这样，电子管才能正常工作。
If it is off - underbias (too little voltage) the tubes will glow red hot, the amp will hum and sound lousy. 如果没有这个负电压，或者该电压太低，电子管会立刻烧红，音箱会发出很大的噪音，并且声音听起来很不正常。
If there is too much bias (overbias,) you will be low on power, and tone will suffer. 如果这个电压太高（过分偏置），那么音箱整体输出功率会下降，音色也会受损。
Set the bias all by yourself is not terribly hard, learn to do it and keep your amp working perfectly for years. 学着自己设置偏置电压其实是一件很简单的事情，这样做可以让你的音箱保持良好状态，延长寿命很多年。
old amplifiers very rarely have had the bias "filter capacitor" replaced. 那些老旧的音箱基本上滤波电容都是更换过的。
If it is bad it sends a bad hum into the amp. 如果滤波电容坏了，音箱的噪音会非常大。
If we find it bad we will upgrade and replace it if necessary. 这种情况下，我们应该立刻升级，更新已经失效的电容。
Ground Switches. 地线切换开关
Ground switches no longer meet federal safety standards. 目前，地线切换开关已经不再是美国联邦安全标准所要求必须安装的了。
As we enter the 21st century knowledge from the 50's and 60's becomes more distant and obscure. 步入21世纪，那些1950年代和1960年代的知识渐渐远去和模糊。
Often we don't know exactly how things such as tube amplifiers were designed to work, causing a bit of confusion in both terms and function. 我们大多数人不清楚电子管放大器是如何设计出来的，与之相关的专用术语及其功能也变得混淆。
Maybe this simple page will make it clearer. 我希望通过这几页简单的叙述，能够把它讲的清楚。
Volume Controls. 音量旋钮
The volume control isn't a "gas pedal," the numbers are not a measurement of how much power is being used. 音量旋钮并不是音箱的“油门”，上面的刻度数字也不代表实际的功率输出。
That is, on a 100 watt amp, 5 is not 50 watts. 比如说一个100瓦的音箱，音量打到刻度5 ，并不代表此时输出功率是50瓦。
In general, Fender and Marshall amps all begin to "break up" or distort just above four. 一般来说，Fender 和 Marshall 的音箱在刻度4以上开始逐渐破碎，或者说开始失真。
The amp is putting out its full clean power at about three and a half. 音箱在刻度3.5左右达到清音程度的最大音量。
Early catalogs will bear this fact out. 你在调节其他旋钮的时候，必须时刻牢记这一点。
Why have the knob go to 10 then? 那么为什么所有音量旋钮的最大刻度都是10 呢？
Owners were expected to know about amplifiers and be aware that you couldn't turn it all the way up and expect a clean sound. 使用吉他音箱的人都应该清楚一点，你不能指望把旋钮都开到最大的时候，还可以得到清音的音色。
The instructions given were "if you notice distortion turn the volume down." 一个基本的指导原则就是：当你发现已经产生失真了，就应该调低音量旋钮。
The other reason for the wide range on the volume control was because guitars have an extremely wide range of output levels. 另外一个必须给音量旋钮这么大调节空间的原因是：吉他本身的信号输出范围其实是非常大的。
A Les Paul has about four times the output of a Telecaster and about six times the output of a Rickenbacker. 一把Les Paul的输出信号是Telecaster 的四倍，并且是 Rickenbacker 的六倍。
The manufacturers wanted to have their amp put out the full RMS power with any guitar. 制造商当然应该考虑到，他们设计制造的音箱应该能够适应各种类型的电吉他信号。
Master Volume Controls. 主音量Master 旋钮
Again, these are not gas pedals and not calibrated (5 isn't half power.) 同样的，这个旋钮也不是“油门” ，刻度数字也不是精确的（刻度5并不是输出一半功率）。
Master volumes were added to the amp designs in the mid to late 60's. 直到1960年代的中期，才在吉他音箱上首次出现主音量Master旋钮。
The idea was to be able to turn the preamp (the regular volume) up causing distortion，and then turn the actual volume of the amplifier down with the master volume so the distorted tones were available at a reasonable overall volume. 设置这个旋钮的目的是：增大前级的放大能力直到产生失真，然后使用Master旋钮把总体音量降低到合理的水平。
But master volumes don't work exactly like that as they are still within the amplifiers preamp circuit (and aren't controlling the final sound to the speakers.) 但是Master旋钮仍然属于前置放大级的范畴，所以它的表现并不完全跟前面叙述的一致（他们并不是直接控制扬声器）
Turning a master volume down causes some degree of distortion no matter where the regular volume is set. 不论音量旋钮在哪个位置，降低Master旋钮都会导致失真度在一定程度上略有下降。
If you want your amp to be as clean as possible, turn the master volume all the way up to 10. 如果你想得到最大音量的清音音色，Master旋钮必须开到最大刻度10
For clean tone - Turn the master all the way up, turn the regular volume down.
为了得到清音音色，你应该开大Master旋钮，而降低音量旋钮。
For distorted tones - Turn the master down, turn the regular volume up. 为了得到失真音色，你应该降低Master旋钮，而打开音量旋钮。
There are hundreds of combinations of master volume and regular volume. 这两个旋钮的组合方式有几百种，慢慢试吧。
Tone control circuits. 音调控制旋钮
Fender and Marshall amps share the same basic tone circuit. 芬达和马勺的音调控制电路基本原理是一致的。
This is not an active circuit and the controls are not "notch filters." 他们都使用了被动式电路，也就是所谓的“带阻”式滤波电路。
That is, they are not really tone controls that select a specific frequency response and boost or cut it. 这就是说，他们并不是选取某一部分频率，主动把它增强。
The treble control is more of a "mixer" between high frequencies and low frequencies than a treble control - it has a great deal of gain available. 高音旋钮其实并不是仅仅增强高频部分，它更像是一个高频与低频的混合器——它具有很大的增益调节空间。
Midrange controls are actually tone circuit gain controls that, within the circuit design, appear to boost midrange. 而中音旋钮则更像一个中频推进器，从电路设计角度来说，它的确是一个中频增益控制旋钮。
The amps can become muddy sounding with all the tone controls at 10. 在所有音调旋钮都打到10的位置的时候，声音会变得异常的发闷。
It's a good idea to evaluate the tone of the amp as you hear it instead of trying to duplicate some settings you've read in a magazine. 一边听声音一边调节音调旋钮的方式，比你试图直接从吉他杂志上复制那些设置参数更重要。
In general, any list of "settings" is very vague and inaccurate 一般来说，这些所谓的设置参数其实都很不准确
and would only apply to one person's playing technique with one particular guitar, plugged into a specific amplifier, with an individual speaker, in the same exact room - you can see - pretty inaccurate to your playing conditions. 你使用的吉他、特定的音箱、特定的扬声器、你的房间以及你的演奏方式，其实都会影响到最终得到的声音。
Boost Circuits used on Torres Amps. 推进旋钮（Torres 音箱）
Midrange boost. 中频推进旋
It increase gain, midrange and sustain. 它可以改变增益、中频响应以及延音。
It works best with the treble control turned up to 6 or higher and is not active at all with the treble below 4. 只有在高频旋钮大于6的时候它才起作用，如果高频旋钮小于4 则完全失效。
Gain Boost. 增益推进旋钮
It increase gain, bass and overdrive. 它会改变增益，低频响应以及失真度。
It gets its effect by deactivating part of the tone control circuit. 音调控制电路部分失效的时候，这个旋钮才变得比较有用。
When the gain boost is on, the tone controls are not as effective.当增益推进旋钮被激活的时候，音调旋钮则会失效。
Bright switch. 明亮音色开关
The standard guitar amp bright switch works if the volume is turned down a bit. 只有在音量旋钮降低的时候，这个切换开关才显得有用。
If the volume is at 10 the bright switch is out of the circuit. 当音量旋钮开到最大的时候，这个开关完全被旁路，没有效果。
General information for all tube amps. 关于电子管音箱的一些常识。
Most of the used tube amps we are using today were built quite a long while ago, 15 to 30 years. 很多我们正在使用的旧电子管音箱已经有15到30年的历史了。
At that time everyone knew a bit about tubes because everything used them. 那个时代的人多少了解一些电子管的知识，因为他们当时只有电子管可以用。
Now, we are pretty much in the dark about the whole thing, and the Guitar Magazine's "Tube Secrets" articles don't help much. 而当今的我们，则对电子管知之甚少，而且吉他杂志上的“电子管解密”之类的文章也没什么用处。
Tube amplifiers need to have a speaker connected all the time. 电子管功放需要随时有扬声器负载连接在输出端。
This goes for any tube amp, anytime. 这一点对任何类型的电子管功放都一样。
Even if you amp has a line-out, you still need speakers connected. 即使你的音箱有Line Out 端口，也仍然需要一直连接着扬声器负载。
Otherwise it will burn up the tubes and destroy the output transformer. 否则会烧毁电子管，甚至有时会击穿输出变压器。
Some very small tube amps have a headphone jack built in. 有些小型的电子管音箱会有耳机插口。
Usually these amps have a "speaker load" resistor switched in by plugging into the jack. 通常，在插入耳机以后，插座上的开关会把扬声器切换到一个负载电阻上面。
Read the amp instructions. 你应该仔细阅读音箱的说明书。
Note: without very expensive parts, this isn't practical at power levels above 6 - 8 watts. 注意：如果没有昂贵的元件，在6至8瓦以上是无法做到这一点的
Tubes are made of Glass. 通常电子管都是玻璃制作的。
Sure, no problem. 这当然没有什么问题。
But we forget sometimes and toss the amps around in the truck or back of the car. 但是有的时候我们会忘记这一点，直接把音箱往卡车后备箱里面一扔了事。
Its amazing how much they can stand, but you should be aware - glass breaks. 它们的坚固令人惊讶，但是你还是应该小心一些才对，毕竟玻璃是易碎的。
And once a tube is broken, it loses its vacuum and won't work anymore. 一旦玻璃破裂，里面就不再是真空了，电子管也就无法继续正常使用。
Usually the tube will turn white when it loses the vacuum. 通常在电子管破裂漏气以后，你会看见玻璃内部发白。
Discard "white tubes", they will never be any good 你应该把白色的管子换掉，因为他们肯定是坏的。
Tubes Don't live forever. 电子管的寿命是有限的。
One of the main reasons the "mainstream" world left tubes behind is the fact that they are temperamental. 主流音响界抛弃电子管的原因之一就是因为它们的寿命有限。
A brand new tube can last 20 years or 20 minutes and paying a high price for them doesn't really eliminate this. 一支全新的电子管可以使用20年，但是也可能20分钟就失效了，糟糕的是即使你花更高的价钱也并不会改变这一点。
It is a good idea to have spare tubes on hand. 最好的办法是随时备用一套电子管。
Buying matched power tubes will ensure that they have been tested and are good tubes, but it doesn't provide any kind of "any and all conditions" warranty. 购买已经配对的电子管可以保障它们是完好并且经过测试的，但是这也并不能为你提供“任何条件下的”担保。
New Old Stock (NOS) tubes 什么是NOS电子管？
New Old Stock tubes made in America can be very good, but are subject to the same temperamental nature of any item made of glass.崭新库存NOS电子管都是美国造的，质量非常好，但是毕竟它们是玻璃做的，有着所有的玻璃制品一样的弱点。
Almost all the tubes come from Russia, China and Eastern Europe. 现在市场上的电子管几乎全部来自俄罗斯、中国以及东欧。
The old folk-type statement "I just got them so they have to be good" is not valid no matter what brand or who you got the tubes from. 那种“我刚买回来的管子肯定是好的”想法肯定是行不通的，不管是什么牌子的电子管，也不管你是从谁手里买来的电子管。
The tubes being "lit up" does not absolutely mean they are good 电子管能够点亮，并不代表它们就是完好的。
12AX7 tubes. 前级管12AX7
Many tubes had different names in the past. 很多型号的电子管在过去有其他的名字。
The distinctions have evaporated and some tubes with several names are all the same tube now. 有些型号演化成为同一种管子，它们之间的区别逐渐消失。
Most common is the standard 12AX7 preamp tube. 目前最常见的前级电子管型号是12AX7
It has quite a few names. 它也有好几个名字
7025 (industrial equivalent) and ECC83 (British part number.) 它在英国的名字是ECC83，而工业用名称为7025
They used to be different, now they are the same tube. 它们曾经是有区别的，但是目前已经是同一种电子管了。
50's and 60's Fenders specify a mix of 12AX7 and 7025 tubes. 在1950至1960年代制造的Fender音箱都是12AX7和7025混用的
You can replace them all with 12AX7 tubes. 你完全可以直接把它们用全新的12AX7代替
What's a "standby switch?" 什么是Standby开关？
Fenders, Marshalls, Traynors, Boogie's all have one. 大多数吉他音箱都有一个STD开关。
Its purpose is to put the amp on idle while you take a break. 它的目的是，在你暂时休息的时候，使音箱暂时处于待机状态。
The tubes have a filament that has to be heated up in order for the tube to work. 此时电子管灯丝会一直保持热度，以保障你随时开机使用。
Heating the filament is why the amp has to "warm up."烧热电子管灯丝需要时间，因此音箱使用之前需要“热机”
The standby switch leaves the filament heated up, and turns off the power and preamp stages. 如果有Standby开关的话，就可以在关闭前级、后级放大电路的情况下，安心地等待灯丝慢慢烧热。
You can flip the standby switch off after a break and play right away. 你还可以在排练、演出的休息空挡时间关闭Standby开关，让音箱也暂时休息一会。
This extends tube life, as the filament doesn't have to be reheated every 45 minutes. 这样做可以有效延长电子管寿命，因为关机以后，45分钟之内电子管灯丝不应该被重新加热。
For a short break in the bar or club, put it on standby. 在排练、演出的空挡时间应该使用Standby暂停。
But, if you and the other guys in the band are going away - turn all the amps completely off. 不过如果你们演出完打算离开，则应该把音箱电源完全关闭。
A tube can go bad at any time. 电子管在任何时候都有可能出问题。
If the amp is on standby when the tube shorts out, you may have some damage. 如果音箱一直处于Standby状态，而电子管又坏了，那么你的音箱电路会因此受到损伤。
Only use the Standby switch when you are still around the amp. 所以你应该在有人随时需要用音箱的时候，使用Standby功能。
When you first turn the amp on, turn on the on-off switch, but leave it on standby for about 2 minutes. 你打开电子管音箱的时候，先打开总电源开关，但是Standby开关要处于关闭状态，并保持两分钟以上
This allows the filaments to heat up and be working right before you start playing. 这样就能使灯丝充分烧热，随时准备你开机演奏了。
Technology upgrades. Older amps. 老旧音箱的升级
When we work on older amps there are some parts that are becoming increasingly defective. 我们使用一些老旧音箱时，还发现他的某些部分已经严重退化。
The amplifier's power supply has "filter capacitors." 尤其是电源的滤波电容。
If the amp is over 22 years old and hasn't been serviced we will, most likely, have to replace the filter capacitors in the amp. 如果音箱已经达到22岁高龄，平时又没有良好的养护，那么它们大多都需要更换滤波电容。
What's bias? 什么是偏置？
Well, I won't go into all the voltage potential, reverse grid bias etc. 好吧，我不打算在上这里深入讲解什么是反偏负栅压。
mumbo jumbo. 那些知识对音箱使用者来说意义不大。
But be aware that the amp has an adjustment that has to be made with different tubes, and as tubes wear out. 不过我们应该知道，使用不同的后级管，以及随着后级管的损耗，音箱电路需要调整偏置电压以适应它的变化，
Anytime you change the power tubes the bias should be adjusted or at least looked at. 更换新的后级电子管以后，你必须重新调节偏置电压。
Again, no matter what brand etc. 重申一次，这跟你使用什么牌子的电子管无关。
The Bias is a negative voltage fed to the tubes. 偏置电压是加载到电子管栅极的一个负直流电压。
It makes them work right, and sound right. 只有这样，电子管才能正常工作。
If it is off - underbias (too little voltage) the tubes will glow red hot, the amp will hum and sound lousy. 如果没有这个负电压，或者该电压太低，电子管会立刻烧红，音箱会发出很大的噪音，并且声音听起来很不正常。
If there is too much bias (overbias,) you will be low on power, and tone will suffer. 如果这个电压太高（过分偏置），那么音箱整体输出功率会下降，音色也会受损。
Set the bias all by yourself is not terribly hard, learn to do it and keep your amp working perfectly for years. 学着自己设置偏置电压其实是一件很简单的事情，这样做可以让你的音箱保持良好状态，延长寿命很多年。
old amplifiers very rarely have had the bias "filter capacitor" replaced. 那些老旧的音箱基本上滤波电容都是更换过的。
If it is bad it sends a bad hum into the amp. 如果滤波电容坏了，音箱的噪音会非常大。
If we find it bad we will upgrade and replace it if necessary. 这种情况下，我们应该立刻升级，更新已经失效的电容。
Ground Switches. 地线切换开关
Ground switches no longer meet federal safety standards. 目前，地线切换开关已经不再是美国联邦安全标准所要求必须安装的了。
