How We Test Amplifiers如何测试放大器 [复制链接]

• Measurements were made at 120V AC line voltage, with volume control fully up unless otherwise noted.
• Gain
  • Ultralinear: 19.7X, 25.9 dB.
  • Triode: 19.0X, 25.6 dB.
• Output noise, 8-ohm load, unbalanced input, 1k-ohm input termination
  • Ultralinear, volume control fully up (worst case): wideband 2.75mV, -60.2dBW; A weighted 0.68mV, -72.4dBW.
  • Ultralinear, volume control fully down (CCW): wideband 1.08mV, -68.4dBW; A weighted 0.29mV, -79.8dBW.
  • Triode, volume control fully up (worst case): wideband 2.57mV, -60.8dBW; A weighted 0.65 mV, -72.8 dBW.
  • Triode, volume control fully down (CCW): wideband 1.02mV, -68.9dBW; A weighted 0.27 mV, -80.4 dBW.
• AC line current draw at idle: 2.03A.
• Output impedance at 50Hz
  • Ultralinear: 0.95 ohms.
  • Triode: 0.92 ohms.
• This integrated amplifier does not invert polarity.

Power output with 1kHz test signal

• 8-ohm load at 1% THD (ultralinear): 69W
• 8-ohm load at 1% THD (triode): 41W
• 8-ohm load at 10% THD (ultralinear): 74W
• 8-ohm load at 10% THD (triode): 47W
  
  
• 4-ohm load at 1% THD (ultralinear): 18W
• 4-ohm load at 1% THD (triode): 24W
• 4-ohm load at 10% THD (ultralinear): 79W
• 4-ohm load at 10% THD (triode): 49W

General
The Rogue Audio Tempest II is a medium-power stereo push-pull tube integrated amplifier utilizing one pair of Electro Harmonix KT88EH output tubes in each channel. This amp has the usual passive-selector-switch/balance/volume-control arrangement ahead of the power amplifier proper. Additionally, it has jumpers that can be changed to access directly the power amplifier input, bypassing the passive front end for external preamp use.
Charts 1A and 1B shows the frequency response of the amp with varying loads for both ultralinear and triode modes. The output impedance, as judged by the closeness of spacing between the curves of open-circuit, 8-ohm, and 4-ohm loading over most of the audio range, is somewhat lower than typical for tube power amplifiers. The variation with the NHT dummy load in the audio range is about +/-0.6dB. The ultralinear mode has a bit more high-frequency bandwidth than the triode mode.
Charts 2A and B illustrate how total harmonic distortion plus noise versus power varies for 1kHz and SMPTE IM test signals and amplifier output load for the ultralinear and triode modes. Unusually, this design, with its single output connection for speaker loads, produces about the same power at the point of clipping for both 4- and 8-ohm loading, albeit at higher distortion prior to clipping. The amplifier has a 4-ohm output winding that can be connected to the hot output terminal instead of the 8-ohm tap if desired for lower-impedance speaker loads. This behavior would suggest equal power into 4- or 2-ohm loads with the 4-ohm windings connected to the output terminals.
Total harmonic distortion plus noise as a function of frequency at several different power levels is plotted in Chart 3 for the ultralinear mode. Appearance for the triode mode was virtually the same except for the two higher powers that were 20W and 35W. Amount of rise in distortion at low and high frequencies is quite pronounced, but not atypical for many tube power amps. Excessive distortion at higher powers and high frequencies prevented a run at rated power both in ultralinear and triode modes.
Damping factor versus frequency is shown in Chart 4 and rolls off at low and high frequencies quite a bit more than other measured tube power amplifiers. This can be inferred in Chart 1 from the increased spacing between the curves at low and high frequencies.
A spectrum of the harmonic distortion and noise residue of a 10W 1kHz test signal is plotted in Chart 5. AC-line harmonics are quite numerous but reasonably low in magnitude, and intermediation components of line harmonics with signal harmonics are also reasonably low but visible. The decay of signal harmonics with frequency is nice and uniform.

• 测量是在120V交流电压带音量控制，全中，除非另有说明。
• 增益
  • 超线性：19.7X，25.9分贝。
  • 三极管：19.0X，25.6分贝。
• 输出噪声，8欧姆负载，不平衡输入，1K的欧姆的输入端接
  • 超线性，音量控制完全达到（最坏情况）：宽带2.75mV，- 60.2dBW，一个加权0.68mV，- 72.4dBW。
  • 超线性，音量控制完全按下去（逆时针）：宽带1.08mV，- 68.4dBW，一个加权0.29mV，- 79.8dBW。
  • 三极管，音量控制完全达到（最坏情况）：宽带2.57mV，- 60.8dBW，一个加权0.65毫伏，-72.8无国界医生组织。
  • 三极管，音量控制完全按下去（逆时针）：宽带1.02mV，- 68.9dBW，一个加权0.27毫伏，-80.4无国界医生组织。
• 交流线电流消耗在空闲：2.03A。
• 在50Hz输出阻抗
  • 超线性：0.95欧姆。
  • 三极管：0.92欧姆。
• 这种集成放大器的极性不能倒置。

功率输出1kHz的测试信号

• 8欧姆负载1％总谐波失真（超线性）：69W
• 8欧姆负载1％总谐波失真（三极管）：41W
• 8欧姆负载为10％总谐波失真（超线性）：74W
• 8欧姆负载为10％总谐波失真（三极管）：47W
  
  
• 4欧姆负载1％总谐波失真（超线性）：18瓦
• 4欧姆负载1％总谐波失真（三极管）：24周
• 4欧姆负载为10％总谐波失真（超线性）：79W
• 4欧姆负载为10％总谐波失真（三极管）：49W

一般
盗贼音频暴风雨II是一个中等功率的立体声推挽放大器集成利用一管电管Harmonix的KT88EH对每个输出通道。 这种放大器具有一般passive-selector-switch/balance/volume-control提前安排适当的功率放大器。 此外，它可以改变的直接访问功率放大器输入，绕过了对外部放大器使用被动前端跳线。
图1A和1B表明了两种不同的超线性与三极管模式和负载放大器的频率响应。 输出阻抗，如之间开路，8欧姆，4欧姆负荷曲线间距以上的音频范围最亲密判断，是有点比管功率放大器典型的低。 与音频范围内的假负载变化莱科萨斯约+ / -0.6分贝。 超线性模式的多一点三极管模式高频率带宽。
图2A和乙说明如何与总谐波失真加噪声功率为1kHz的测试及SMPTE即时通讯信号和超线性模式和三极管放大器输出负载变化。 与众不同的是，这与它的扬声器负载单输出接口设计，生产于裁剪为4点左右相同的功率 - 和8欧姆的负载，尽管之前在较高的剪切变形。 该放大器有一个4欧姆输出线圈，可连接到炎热的输出端，而不是8欧姆水龙头如果低阻抗扬声器负载所需。 此行为会建议为4平等的权力 - 或连接到输出端子的4欧姆绕组2欧姆负载。
总谐波失真加作为频率的函数噪声功率水平在几个不同的是在图3所示为超线性模式。 在三极管模式的出现，实际上除了这两个更高的权力被20W的和35W的相同。 崛起中的低失真和高频率的金额是相当明显，但对于许多非典型功放管。 在高频率更高的权力和防止过度扭曲无论是在超线性和三极管模式，在额定功率运行。
阻尼因子与频率显示在图4和滚降低，高频率相当多的比其他测量管功率放大器。 这可以推断，从图1中的曲线之间的低增长和高频率的间距。
阿的谐波失真和10W的1kHz的测试信号噪声频谱残留绘制于图5。 交流线路的谐波幅度相当众多，但在合理的低，以及与信号谐波的谐波在线中介组件也相当低，但可见。 谐波的信号衰减随频率是好的和统一。

• Measurements were made with 120V AC line voltage.
• Gain: 71.2x, 37dB.
• Output noise, 8-ohm load, unbalanced input, 1k-ohm input termination: wideband 0.309mV, -79.2dBW; A weighted 0.084mV, -90.4dBW.
• Output noise, 8-ohm load, balanced input, 600-ohm input termination: wideband 0.288mV, -79.8dBW; A weighted 0.087mV, -90.2dBW.
• AC line current draw at idle: 0.46A.
• Output impedance at 50Hz: 0.0014 ohms.
• This amplifier does not invert polarity.

Power output with 1kHz test signal

• 8-ohm load at 1% THD: 440W
  
  
• 4-ohm load at 1% THD: 770W

General
The Moon W-6 is a high-power solid-state design with typically wide bandwidth and very low output impedance.
Chart 1 shows the frequency response of the amp with varying loads. As can be seen, the output impedance, as judged by the closeness of spacing between the curves of open circuit, 8-ohm, and 4-ohm loading, is quite low. The variation with the NHT dummy load would be absolutely negligible. Chart 2 illustrates how total harmonic distortion plus noise versus power varies for 1kHz and SMPTE IM test signals and amplifier output load. As can be seen, attainable power is greater for the 4-ohm load as is usual for most power amplifiers. Total harmonic distortion plus noise as a function of frequency at several different power levels is plotted in Chart 3. Amount of rise in distortion at high frequencies is typical of most modern solid-state power amplifiers. Note how the amount of distortion here is fairly constant with power level over much of the frequency range. Damping factor versus frequency is shown in Chart 4. Unusual is how high the damping factor is at low frequencies. A spectrum of the harmonic distortion and noise residue is plotted in Chart 5. The AC-line harmonics are quite low for this amplifier. The test-signal harmonics are dominantly odd harmonic with a slow falloff of magnitude with harmonic order.

Red line: open circuit
Magenta line: 8-ohm load
Blue line: 4-ohm load

(line up at 10W to determine lines)
Top line: 4-ohm SMPTE IM
Second line: 8-ohm SMPTE IM
Third line: 4-ohm THD+N
Bottom line: 8-ohm THD+N

8-ohm output loading
Green lin: 400W
Cyan line: 200W
Blue line: 70W
Magenta line: 10W
Red line: 1W

Damping factor = output impedance divided into 8

• 测量是用120V交流电压。
• 增益：71.2x，三七分贝。
• 输出噪声，8欧姆负载，不平衡输入，1K的欧姆输入终端：宽带0.309mV，- 79.2dBW，一个加权0.084mV，- 90.4dBW。
• 输出噪声，8欧姆负载，平衡输入，600欧姆的输入端接：宽带0.288mV，- 79.8dBW，一个加权0.087mV，- 90.2dBW。
• 交流线电流消耗在空闲：0.46A。
• 在50Hz输出阻抗：0.0014欧姆。
• 该放大器的极性不能倒置。

功率输出1kHz的测试信号

• 8欧姆负载，1％总谐波失真：440W
  
  
• 4欧姆负载，1％总谐波失真：770W

一般
月亮的W - 6是一个高功率固体状态与一般宽的带宽和非常低的输出阻抗设计。
图1显示了用不同的负载放大器的频率响应。 可以看出，输出阻抗，作为判断之间开路，8欧姆，4欧姆负荷曲线间距接近，是相当低的。 与莱科萨斯假负载变化是绝对可以忽略不计。 图2说明了总谐波失真加噪声功率比和SMPTE即时1kHz的测试信号和放大器的输出负载变化。 可以看出，可实现功率为4欧姆负载的是常见的，最功率放大器更大。 总谐波失真加作为频率的函数噪声功率水平在几个不同的是在图3所示。 在高频率的失真崛起的数额最现代化的固态功率放大器的典型。 请注意这里的失真量相当与供电频率范围多水平不变。 阻尼频率因子与图4所示。 难得的是有多高阻尼因数低频率的。 阿的谐波失真和噪声残留谱绘制于图5。 在交流线路谐波此放大器是相当低的。 测试信号的谐波为主奇数与一个数量级谐波与谐波衰减缓慢秩序。

• Measurements were made with 120V AC line voltage with one channel driven (this is a mono amplifier), driving the unbalanced inputs unless otherwise noted.
• Gain: 39.4x, 31.9dB unbalanced input; 11.0x, 20.8dB balanced input.
• Output noise, 8-ohm load, unbalanced input, 1k-ohm input termination: wideband 0.185mV, -83.7dBW; A weighted 0.088mV, -90.1dBW.
• Output noise, 8-ohm load, balanced input, 600-ohm input termination: wideband 0.169mV, -84.5dBW; A weighted 0.081mV, -90.9dBW.
• AC line current draw at idle: 0.76A.
• Output impedance at 50Hz: 0.25 ohms.
• This amplifier does not invert polarity.

Power output with 1kHz test signal

• 8-ohm load at 1% THD: 155W
• 8-ohm load at 10% THD: 210W
  
  
• 4-ohm load at 1% THD: 244W
• 4-ohm load at 10% THD: 364W

General
The Stello M200 is a medium-power solid-state design with typically wide bandwidth and output impedance higher than is usual with solid-state amplifiers. Some of its characteristics -- for example, the way distortion varies with power, the damping factor, and the uniformity of amount of distortion and damping factor with frequency -- are more like those of a well-designed tube amplifier.
Chart 1 shows the frequency response of the amp with varying loads. As can be seen, the output impedance, as judged by the closeness of spacing between the curves of open circuit, 8-ohm, and 4-ohm loading, is quite low. The variation with the NHT dummy load in the audio range is of the order of +/-0.25dB.
Chart 2 illustrates how total harmonic distortion plus noise vs. power varies for 1kHz and SMPTE IM test signals and amplifier output load. As can be seen, attainable power is greater for the 4-ohm load, as is usual for most power amplifiers. Further, the way that the distortion increases as power nears maximum is a much softer curve than is typical for a solid-state amplifier. This indicates the possibility of low amounts of overall feedback in the design.
Total harmonic distortion plus noise as a function of frequency at several different power levels is plotted in Chart 3. In order to eliminate out-of-band noise and more accurately measure the amount of distortion in this plot, the AES-17 sharp-cutoff 40kHz low-pass filter was used instead of the usual 80kHz filter. The amount of rise in distortion at high frequencies is very low in this design. The number of amplifiers that I have encountered in my experience with this attribute is now countable on two hands rather than one.
Damping factor vs. frequency is shown in Chart 4 and is moderate but quite constant with frequency.
A spectrum of the harmonic distortion and noise residue of a 10W 1kHz test signal is plotted in Chart 5. The magnitude of the AC-line harmonics is quite numerous and intermodulation components of line harmonics with signal harmonics are also very numerous and visible. The test-signal harmonics are both even and odd and don't decline or tail-off with frequency vary quickly.

Red line: open circuit
Magenta line: 8-ohm load
Blue line: 4-ohm load
Cyan line: NHT dummy-speaker load

(line up at 20W to determine lines)
Top line: 4-ohm SMPTE IM
Second line: 8-ohm SMPTE IM
Third line: 4-ohm THD+N
Bottom line: 8-ohm THD+N

4-ohm output loading
Cyan line: 200W
Blue line: 70W
Magenta line: 20W
Red line: 2W

Damping factor = output impedance divided into 8

1kHz signal at 10W into a 4-ohm load

• 测量是用120伏交流电压驱动与一个通道（这是一个单声道放大器），驱动非平衡输入，除非另有说明。
• 增益：39.4x，31.9分贝不平衡输入; 11.0x，二十○点八分贝平衡输入。
• 输出噪声，8欧姆负载，不平衡输入，1K的欧姆输入终端：宽带0.185mV，- 83.7dBW，一个加权0.088mV，- 90.1dBW。
• 输出噪声，8欧姆负载，平衡输入，600欧姆的输入端接：宽带0.169mV，- 84.5dBW，一个加权0.081mV，- 90.9dBW。
• 交流线电流消耗在空闲：0.76A。
• 在50Hz输出阻抗：0.25欧姆。
• 该放大器的极性不能倒置。

功率输出1kHz的测试信号

• 8欧姆负载，1％总谐波失真：155W
• 8欧姆负载为10％总谐波失真：210W
  
  
• 4欧姆负载，1％总谐波失真：244W
• 4欧姆负载为10％总谐波失真：364W

一般
该Stello M200的是一个中等功率的固态与一般宽的带宽和更高的输出阻抗比与固态放大器通常的设计。 它的一些特点 - 例如，扭曲的方式随功率，阻尼因素，金额失真和衰减系数与频率的一致性 - 更像是一个精心设计的电子管功率放大器的。
图1显示了用不同的负载放大器的频率响应。 可以看出，输出阻抗，作为判断之间开路，8欧姆，4欧姆负荷曲线间距接近，是相当低的。 与音频范围内的莱科萨斯假负载的变化，是秩序+ / -0.25分贝。
图2说明了总谐波失真加噪声与功率1kHz的测试信号和SMPTE的IM和放大器的输出负载变化。 可以看出，可实现功率为4欧姆负载更大，因为是常见的，最功率放大器。 此外，作为权力的方式，增加接近最大的扭曲是一个更柔和的曲线比为固态放大器的典型。 这表明了在设计整体反馈低量的可能性。
总谐波失真加作为频率的函数噪声功率水平在几个不同的是在图3所示。 为了消除了带外噪音和更准确地衡量这个阴谋的失真量的，AES - 17锐截止40kHz的低通滤波器的过滤器，而不是通常的80kHz的使用。 在高频率的失真上升量非常低，这种设计。 那个我在用这个属性所遇到放大器的数目，现已两只手可数，而不是一个。
阻尼随频率变化的因素是在图4所示，是相当温和的，但与频率的关系。
阿的谐波失真和10W的1kHz的测试信号噪声频谱残留绘制于图5。 将AC -线路谐波幅度相当众多的线路谐波​​和互调分量信号谐波也非常多，而且可见。 测试信号谐波都是偶数和奇数，不减少或过频的尾巴与迅速变化。

• Measurements were made with 120V AC line voltage.
• Power output and distortion plotted with both channels driven.
• Gain: 24.8x, 27.9dB.
• Output noise, 8-ohm load, unbalanced input, 1k-ohm input termination: wideband 0.260mV, -80.7dBW; A weighted 0.129mV, -86.8dBW.
• Output noise, 8-ohm load, balanced input, 600-ohm input termination: wideband 0.198mV, -83.1dBW; A weighted 0.100mV, -89.0dBW.
• AC line current draw at idle (warmed up): 1.4A.
• Output impedance at 50Hz: 0.0085 ohms.
• This amplifier does not invert polarity.

Power output with 1kHz test signal

• 8-ohm load at 1% THD: 300W
  
  
• 4-ohm load at 1% THD: 520W

General
The Threshold S/5000e is a high-power solid-state design with extremely low output impedance and a relatively high output-stage idling current. The idling current is quite stable with increasing temperature as the amp warms up. Furthermore, and most importantly, the idling current stays stable when the amp is heated up under higher-power conditions.
Chart 1 shows the frequency response of the amp with varying loads. As can be seen, the output impedance, as judged by the closeness of spacing between the curves of open circuit, 8-ohm and 4-ohm loading, is very low. In the case of the S/5000e, this variation with the NHT dummy load would be about a negligible +/-0.01dB. Chart 2 illustrates how total harmonic distortion plus noise versus power varies for 1kHz and SMPTE IM test signals and amplifier output load. As can be seen, attainable power is greater for the 4-ohm load, as is usual for most power amplifiers. Total harmonic distortion plus noise as a function of frequency at several different power levels is plotted in Chart 3. Amount of rise in distortion at high frequencies is relatively low -- a desirable characteristic. Damping factor versus frequency is shown in Chart 4. This is one of the lowest output impedance amplifiers tested at BHK labs. A spectrum of the harmonic distortion and noise residue is plotted in Chart 5. As seems to be the case with many amplifiers measured, this one has a rich series of AC line hum harmonics with some sidebands of these harmonics about the nulled fundamental frequency and the signal harmonics.

Magenta line: open circuit
Red line: 8-ohm load
Blue line: 4-ohm load
Cyan line = NHT dummy-speaker load

(line up at 100W to determine lines)
Top line: 4-ohm SMPTE IM
Second line: 8-ohm SMPTE IM
Third line: 4-ohm THD+N
Bottom line: 8-ohm THD+N

4-ohm output loading
Cyan line: 450W
Blue line: 120W
Magenta line: 20W
Red line: 2W

Damping factor = output impedance divided into 8

1kHz signal at 10W into a 4-ohm load

• 测量是用120V交流电压。
• 输出功率和失真策划既带动渠道。
• 增益：24.8x，二十七点九分贝。
• 输出噪声，8欧姆负载，不平衡输入，1K的欧姆输入终端：宽带0.260mV，- 80.7dBW，一个加权0.129mV，- 86.8dBW。
• 输出噪声，8欧姆负载，平衡输入，600欧姆的输入端接：宽带0.198mV，- 83.1dBW，一个加权0.100mV，- 89.0dBW。
• 交流线电流在空闲（热身）：1.4A的。
• 在50Hz输出阻抗：0.0085欧姆。
• 该放大器的极性不能倒置。

功率输出1kHz的测试信号

• 8欧姆负载，1％总谐波失真功率：300W
  
  
• 4欧姆负载，1％总谐波失真：已完成520W

一般
门槛S/5000e是一种高功率固体具有极低的输出阻抗和相对高的输出级空载电流设计。 空载电流随温度相当放大器升温稳定。 此外，最重要的是，怠速稳定，加热时，放大器在高功率条件下电流住宿。
图1显示了用不同的负载放大器的频率响应。 可以看出，输出阻抗，作为判断之间开路，8欧姆和4欧姆负荷曲线间距接近，是很低的。 在S/5000e，这与莱科萨斯假负载的变化情况将大约微不足道+ / -为0.01dB。 图2说明了总谐波失真加噪声功率比和SMPTE即时1kHz的测试信号和放大器的输出负载变化。 可以看出，可实现功率为4欧姆负载更大，因为是常见的，最功率放大器。 总谐波失真加作为频率的函数噪声功率水平在几个不同的是在图3所示。 在高频率的变形量相对较低崛起 - 一个理想的特征。 阻尼频率因子与图4所示。 这是最低的输出阻抗放大器之一的BHK实验室测试。 阿的谐波失真和噪声残留谱绘制于图5。似乎是由于与实测许多放大器的情况下，这其中有一个基本的关于清零信号的频率和谐波这些谐波一些边带谐波的交流线路哼哼丰富系列。