How We Test Amplifiers如何测试放大器 [复制链接]

• Measurements were made with 120V AC line voltage with both channels driven using the balanced inputs (there are only balanced inputs present on this amplifier).
• Gain: 17.6x, 24.9dB.
• Output noise, 8-ohm load, balanced input, 600-ohm input termination: wideband 0.440mV, -76.2dBW; A weighted 0.130mV, -86.8dBW.
• AC line current draw at idle: 1.72A.
• Output impedance at 50Hz: 0.0049 ohms.
• This amplifier inverts polarity.

Power output with 1kHz test signal

• 8-ohm load at 1% THD: 200W
  
  
• 4-ohm load at 1% THD: 350W

General
The Accustic Arts Amp II-AC High Performance is a very large and heavy but medium-/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 in the audio range is negligible. What is unusual about this design is that the curves stay virtually overlaid all the way out to 200kHz.
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. The amount of rise in distortion at high frequencies is fairly pronounced, and is similar to that of many amplifiers measured. Note that the curves for the higher powers of 100W and 300W don't extend all the way to 20kHz as the amp's protection circuit came into play above the highest frequencies shown on these curves.
Damping factor vs. frequency is shown in Chart 4 and is unusually high.
A spectrum of the harmonic distortion and noise residue is plotted in Chart 5. The magnitude of the AC-line harmonics is unusually low in this design. At the test level of 10W into 4 ohms, the signal harmonics are admirably low, with only the second harmonic showing above the noise level. Note that from the additional data the noise level is a bit higher than that of some other recent amplifiers measured and some of the higher signal harmonics may be under this noise level -- but also note that they would be less than 0.0001%.

Red line: open circuit
Magenta line: 8-ohm load
Blue line: 4-ohm 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: 300W
Blue line: 100W
Magenta line: 20W
Red line: 2W

Damping factor = output impedance divided into 8

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

• 测量与120V交流电压驱动的使用作出平衡输入两个通道（只有平衡输入此放大器至今）。
• 增益：17.6x，二十四点九分贝。
• 输出噪声，8欧姆负载，平衡输入，600欧姆的输入端接：宽带0.440mV，- 76.2dBW，一个加权0.130mV，- 86.8dBW。
• 交流线电流消耗在空闲：1.72A。
• 在50Hz输出阻抗：0.0049欧姆。
• 该放大器颠倒极性。

功率输出1kHz的测试信号

• 8欧姆负载，1％总谐波失真功率：200W
  
  
• 4欧姆负载，1％总谐波失真输出功率：350W

一般
二，艺术放大器的Accustic - AC的高性能是一个非常大而重，但medium-/high-power固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欧姆和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可以忽略不计。 这种设计是什么样的曲线难得的是，几乎覆盖所有留出路至200kHz。
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。 在高频率的失真上升的数量也相当明显，而且是许多类似的测量放大器的。 请注意，对于100W和300W更高的力量的曲线不一路延伸到20kHz作为放大器的保护电路成以上这些曲线上显示的最高频率播放来了。
阻尼随频率变化的因素是在图4所示，是非常高。
阿的谐波失真和噪声残留谱绘制于图5。 将AC -线路谐波的幅度非常低，这种设计。 在为4欧姆10W的测试水平，是令人钦佩的信号谐波低，只有第二个以上的噪音水平谐波展示。请注意，从其他数据的噪音水平是一个比其他一些测量放大器和最近的一些更高的信号谐波可根据本噪音水平更高 - 但也注意到，他们将小于0.0001％。

红线：开路
洋红色线条：8欧姆负载
蓝线：4欧姆负载

（线在20W的，以确定线路）
热门线路：4欧姆的SMPTE的IM
下联：8欧姆的SMPTE的IM
第三行：4欧姆的THD + N
底线：8欧姆的THD + N

4欧姆输出负载
青色线：300瓦
蓝线：100瓦
洋红色线条：20瓦
红线功率：2W

阻尼因数=输出阻抗为8分

在10W的1kHz的信号为4欧姆负载

• Measurements were made with 120V AC line voltage.
• Power output and distortion plotted with both channels driven.
• Gain: 28.0x, 28.9dB.
• Output noise, 8-ohm load, unbalanced input, 1k-ohm input termination: wideband 0.115mV, -87.8dBW; A weighted 0.028mV, -100.1dBW.
• AC line current draw at idle: 0.41A.
• Output impedance at 50Hz: 0.02 ohms.
• This amplifier does not invert polarity.

Power output with 1kHz test signal

• 8-ohm load at 1% THD: 119W
  
  
• 4-ohm load at 1% THD: 193W

General
The Anthem PVA 2 is a solid-state design with low measured distortion, wide frequency response, and very low output impedance
Chart 1 shows the frequency response of the amp with varying loads. As can be seen, this unit has low output impedance as evidenced by the v ery close spacing of the curves for an open circuit down to 4-ohm loading in the audio range. The deviation above the audio range is common and typical due to the usual presence of a series RL network in the output for circuit stability and the decrease in overall negative feedback with increasing frequency. When an amplifier has such low output impedance, it doesn't make any sense to measure the NHT dummy speaker load as we do for many amplifiers because its impedance variation won't show on the chart. Needless to say, the frequency-response variation with varying-impedance speaker loads with this amp will be negligible. Chart 2 illustrates how total harmonic distortion plus noise versus power varies for a 1kHz sine wave, 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. Distortion up to about 300Hz is very low, but as is typical with most power amplifiers, it does rise as frequency increases. Damping factor versus frequency is shown in Chart 4 and is very high for this design. A spectrum of the harmonic distortion and noise residue is plotted in Chart 5 for a 10W 1kHz signal into a 4-ohm load. Amount of the signal distortion products is very low, as is the amount of AC line-hum harmonics. Virtually absent is the cluster of AC line harmonics around some of the signal harmonics as has been seen in some other amplifiers measured.

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

(line up at 50W 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
Red line: 1W
Magenta line: 10W
Blue line: 30W
Cyan line: 100W

Damping factor = output impedance divided into 8

1kHz signal at 10W into an 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：28.0x，28.9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0.115mV，- 87.8dBW，一个加权0.028mV，- 100.1dBW。
• 交流线电流消耗在空闲：0.41A。
• 在50Hz输出阻抗：0.02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：119W
  
  
• 4欧姆负载，1％总谐波失真：193W

一般
聚乙烯醇的国歌2是一个具有低失真测量，频响宽，输出阻抗和非常低的固态设计
图1显示了用不同的负载放大器的频率响应。 可以看出，本机具有低输出阻抗，由V红霉素的曲线间距开路下降到4欧姆音频范围内的载荷密切可见一斑。 上面的音频范围内的偏差是普遍的，典型的因在对电路的稳定性输出系列RL网络通常存在和整体负反馈随频率的降低。 当放大器具有低输出阻抗，它没有任何意义来衡量莱科萨斯虚拟扬声器负载，因为我们的许多放大器，因为它的阻抗变化不会显示在图表上做。 不用说，用这种放大器的变阻抗的扬声器负载频率响应的变化可以忽略不计。 图2说明了总谐波失真加噪声功率比为1kHz的正弦波，SMPTE的即时测试信号，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。 高达约300Hz的失真非常低，但由于大部分是典型的功率放大器，它随着频率的增加上升。 阻尼因子与频率显示在图4及这种设计是非常高的。阿的谐波失真和噪声残留谱绘制于图5为10W的1kHz时为4欧姆负载信号。 产品的信号失真量非常低，因为是交行的嗡嗡声谐波量。 实际上，缺乏的是交流线路的谐波信号谐波周围的一些集群，这已在其他一些测量放大器看到。

• Measurements were made with 120V AC line voltage with both channels driven, driving the unbalanced inputs unless otherwise noted.
• Gain: 28.3x, 29dB.
• Output noise, 8-ohm load, unbalanced input, 1k-ohm input termination: wideband 0.270mV, -80.4dBW; A weighted 0.050mV, -95.0dBW.
• Output noise, 8-ohm load, balanced input, 600-ohm input termination: wideband 0.205mV, -82.8dBW; A weighted 0.042mV, -96.6dBW.
• AC line current draw at idle: 0.9A.
• Output impedance at 50Hz: 0.0072 ohms.
• This amplifier does not invert polarity.

Power output with 1kHz test signal

• 8-ohm load at 1% THD: 373W
  
  
• 4-ohm load at 1% THD: 609W

General
The Anthem Statement P2 stereo amplifier 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 in the audio range is negligible.
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.
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 fairly pronounced and is similar to that of many amplifiers measured.
Damping factor vs. frequency is shown in Chart 4 and is unusually high.
A spectrum of the harmonic distortion and noise residue is plotted in Chart 5. The magnitude of the AC-line harmonics is low and typical of many of the amplifiers measured at BHK Labs. The test signal harmonics are both even and odd harmonic with the higher-order harmonics smoothly declining with frequency.

Red line: open circuit
Magenta line: 8-ohm load
Blue line: 4-ohm 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
Green line: 500W
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

• 测量了既与120V交流线路电压驱动渠道，推动非平衡输入，除非另有说明。
• 增益：28.3x，为29dB。
• 输出噪声，8欧姆负载，不平衡输入，1K的欧姆输入终端：宽带0.270mV，- 80.4dBW，一个加权0.050mV，- 95.0dBW。
• 输出噪声，8欧姆负载，平衡输入，600欧姆的输入端接：宽带0.205mV，- 82.8dBW，一个加权0.042mV，- 96.6dBW。
• 交流线电流消耗在空闲：可调到0.9A。
• 在50Hz输出阻抗：0.0072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：373W
  
  
• 4欧姆负载，1％总谐波失真：609W

一般
P2的国歌声明的立体声放大器是一种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。 与音频范围内的莱科萨斯假负载的变化可以忽略不计。
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。 在高频率的失真上升的数量也相当明显，是许多类似的测量放大器的。
阻尼随频率变化的因素是在图4所示，是非常高。
阿的谐波失真和噪声残留谱绘制于图5。 将AC -线路谐波幅度很低，在实验室测量放大器的BHK许多典型。 测试信号谐波都是奇数和偶数的高次谐波的谐波顺利频率下降。

• Measurements were made with 120V AC line voltage, using the 8-ohm output terminals, and with one channel driven (this is a mono amplifier).
• Output noise, 8-ohm load, unbalanced input, 1k-ohm input termination, 0dB feedback: wideband 1.14mV, -67.9dBW; A weighted 0.23mV, -81.8dBW.
• Output noise, 8-ohm load, unbalanced input, 1k-ohm input termination, 10dB feedback: wideband 3.78mV, -57.5dBW; A weighted 0.74mV, -71.6dBW.
• AC line current draw at idle: 1.72A.
• Output impedance at 50Hz (0dB feedback): 6.6 ohms.
• Output impedance at 50Hz (10dB feedback): 2.1 ohms.
• This amplifier does not invert polarity.

Power output with 1kHz test signal
0dB feedback

• 8-ohm load at 1% THD: 57W
• 8-ohm load at 10% THD: 70W
  
  
• 4-ohm load at 1% THD: 47W
• 4-ohm load at 10% THD: 68W

10dB feedback

• 8-ohm load at 1% THD: 58W
• 8-ohm load at 10% THD: 72W
  
  
• 4-ohm load at 1% THD: 53W
• 4-ohm load at 10% THD: 68W

General
The Audio Electronic Supply SixPac is a moderate-power tube amp utilizing three pairs of triode-connected EL34 output tubes. Four- or 8-ohm load matching is provided for the output terminals with a two-position toggle switch. A front-panel switch gives the option of 0 or 10dB of negative feedback.
The following measurements were made with the output load selection switch set for 8 ohms. Relative behavior in the 4-ohm position was about the same for 4- and 2-ohm loading. Distortion was measured with the 10dB of feedback applied. In general, distortion without the feedback was about 2-3 times greater.
Chart 1a shows the frequency response of the amp with varying loads and with the 10dB of feedback engaged. Output impedance as judged by the spacing between the various loadings is typical of many tube power amplifiers. The effect on delivered frequency response to a typical speaker load is also shown for the NHT dummy load. Chart 1b is with no feedback. Here, the output impedance is much higher, and, in my personal opinion, too high with the consequence that the delivered frequency response to many speakers would be way off from flat. Chart 2 illustrates how total harmonic distortion plus noise versus power varies for 1kHz and SMPTE IM test signals and amplifier output load. In the case of this amplifier, the 4-ohm loading produces about the same power as with the more "matched" 8-ohm load. Total harmonic distortion plus noise as a function of frequency at several different power levels is plotted in Chart 3. Damping factor versus frequency is shown in Chart 4 for both the 0 and 10dB of feedback. 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 120Hz about the nulled fundamental frequency. The harmonics series of the signal test frequency is quite dense and extends over the rest of the audio range.

(Chart 1a: 10dB feedback)
Red line: open circuit
Magenta line: 8-ohm load
Blue line: 4-ohm load
Cyan line: NHT dummy-speaker load

(Chart 1b: 0dB feedback)
Red line: open circuit
Magenta line: 8-ohm load
Blue line: 4-ohm load
Cyan line: NHT dummy-speaker load

(10dB feedback)
(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

(10dB feedback)
8-ohm output loading
Cyan line: 50W
Blue line: 30W
Magenta line: 10W
Red line: 1W

Damping factor = output impedance divided into 8
Red line: 10dB feedback
Magenta line: 0dB feedback

(10dB feedback)
1kHz signal at 10W into an 8-ohm load

• 测量是用120伏交流电压，使用8欧姆输出端子，并有一个通道驱动（这是一个单声道放大器）。
• 输出噪声，8欧姆负载，不平衡输入，1K的欧姆输入终端，0dB的反馈：宽带1.14mV，- 67.9dBW，一个加权0.23mV，- 81.8dBW。
• 输出噪声，8欧姆负载，不平衡输入，1K的欧姆输入终端，10dB的反馈：宽带3.78mV，- 57.5dBW，一个加权0.74mV，- 71.6dBW。
• 交流线电流消耗在空闲：1.72A。
• 输出阻抗在50Hz（0dB的反馈）：6.6欧姆。
• 输出阻抗在50Hz（10dB的反馈）：2.1欧姆。
• 该放大器的极性不能倒置。

功率输出1kHz的测试信号
0dB的反馈

• 8欧姆负载，1％总谐波失真：57W
• 8欧姆负载为10％总谐波失真功率：70W
  
  
• 4欧姆负载，1％总谐波失真：47W
• 4欧姆负载为10％总谐波失真：68W

10dB的反馈

• 8欧姆负载，1％总谐波失真：58W
• 8欧姆负载为10％总谐波失真：72W
  
  
• 4欧姆负载，1％总谐波失真：53W
• 4欧姆负载为10％总谐波失真：68W

一般
音频电子供应SixPac是一个中等功率电子管功放使用三个三极管连接EL34管双输出。 四或八欧姆负载匹配提供了一个双位拨动开关的输出端。 前面板开关给出0或者负反馈10dB的选项。
以下数据均与输出负荷选择开关设定为8欧姆。 在4欧姆左右的相对位置的行为是相同的4 - 和2欧姆负载。 失真是衡量应用的10分贝的反馈。 一般来说，如果没有反馈失真约为2-3倍。
图1a显示了变载荷，并与从事10dB的放大器反馈的频率响应。 输出阻抗的间距之间的各种负荷判断是许多管功率放大器的典型。 对交付频率响应典型的扬声器负载效果也显示了莱科萨斯假负载。 图1b是没有反馈。 在这里，输出阻抗要高得多，并以我个人的意见，其结果也与高频率响应所交付的许多发言者大概也从平面关闭。 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。 在这种放大器的情况下，4欧姆负荷生产大约相同的，如用更“匹配”8欧姆的负载。 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。 阻尼频率因子与图4所示为0和10分贝的反馈。 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边带频率120Hz的一些交流在线哼谐波丰富系列。 信号的频率谐波测试系列是相当密集，在其余的音频范围延伸。

• Measurements were made with 120V AC line voltage with both channels driven.
• All measurements, except for frequency response, were made with the new Audio Precision Aux-0025 filter, that is especially designed to keep the out-of-band switching noise out of the Audio Precision measurement system and thus prevent inaccurate measurements due to input overload.
• Gain, unbalanced input: 23.3x, 27.3dB.
• Output noise, 8-ohm load, 1k-ohm input termination: wideband 29.0mV, -39.8dBW; A weighted 0.72mV, -71.9dBW.
• AC line current draw at idle: 0.56A.
• Output impedance at 50Hz: 0.047 ohms.
• This amplifier does not invert polarity.

Power output with 1kHz test signal

• 8-ohm load at 1% THD: 166W
  
  
• 4-ohm load at 1% THD: 300W

General
The Audio Research 150.2 is yet another of the new breed of switching amplifiers utilizing the TriPath technology and controller chipset.
Measurements were made through the unbalanced inputs except otherwise noted. Performance through the balanced inputs was essentially the same. 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. However, the ultrasonic response past 20 kHz is a strong function of the load, with strong peaking near 100kHz with an open circuit load. The response with the NHT dummy load is reasonable, with a variation of about +0.6/-0dB over the audio range. Some speakers utilizing dome tweeters, due to the high frequency inductive nature of these types of drivers, may exhibit some fractional part of this resonant rise above the audio range. 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. The TriPath system has a peculiar behavior at power levels approaching clipping. The output waveform starts to exhibit some switching noise near the peaks that will get through the Aux-0025 filter and into the distortion measurement when the bandwidth of the measurement is opened up to 80kHz. Generally, I use the 80 kHz measurement bandwidth to more accurately let some of the actual signal harmonics get through at frequencies at the high end of the audio band. This shows up as the higher distortion at the 200W and 300W levels on the chart, and does not indicate distortion that would necessarily be audible. Damping factor versus frequency is shown in Chart 4. A spectrum of the harmonic distortion and noise residue is plotted in Chart 5. The magnitude of the AC line harmonics is reasonably low for this amplifier. The test signal harmonics are both even and odd harmonic, with the second and third harmonics dominating the total distortion makeup.

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

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

4-ohm output loading
Green line: 300W
Cyan line: 200W
Blue line: 140W
Magenta line: 20W
Red line: 2W

Damping factor = output impedance divided into 8

1kHz signal at 10W into an 8-ohm load

• 测量是用120V交流渠道，既驱动电压。
• 除了所有的测量频率响应，提出了新的音频与精密辅助- 0025过滤器，这是特别设计，以保持外的带开关音频噪声进行精密测量系统测量不准确，从而防止因输入过载。
• 增益，不平衡输入：23.3x，二十七点三分贝。
• 输出噪声，8欧姆负载，1K的欧姆输入终端：宽带29.0mV，- 39.8dBW，一个加权0.72mV，- 71.9dBW。
• 交流线电流消耗在空闲：0.56A。
• 在50Hz输出阻抗：0.047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：166W
  
  
• 4欧姆负载，1％总谐波失真功率：300W

一般
音频150.2又是研究的利用还在Tripath开关放大器技术和新品种的另一个控制器芯片组。
测量是通过投入的不平衡，除了另有说明。 通过平衡输入性能基本上是一样的。 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。 然而，过去20千赫的超声波的响应是一个负载能力强，具有较强的附近有一个开放的电路负载100kHz的高峰。 用假负载响应莱科萨斯是合理的，拥有约+0.6 / - 0dB的音频范围在变化。 一些发言者利用球顶高音扬声器，由于高频感应​​这些类型的驱动程序的性质，可能会出现一些本以上的音频范围谐振上升小数部分。 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。 该系统具有还在Tripath在功率接近剪辑水平奇特的行为。 输出波形开始出现一些接近峰值开关噪声，将获得通过的Aux - 0025过滤器，进入变形测量时，测量带宽是开辟了至80kHz。 一般来说，我用的是80 kHz的带宽，以更准确地测量实际信号，让某些人得到的谐波在音频频段高端频率通过。 这表明，作为在图表上的200瓦和300瓦的水平变形，扭曲，并不表示一定会听到。 阻尼频率因子与图4所示。 阿的谐波失真和噪声残留谱绘制于图5。 交流线路的幅度是合理的低谐波此放大器。 测试信号谐波都是偶次谐波，与第二个和第三个谐波总失真化妆称霸。

• Measurements were made at 120V AC line voltage with both channels driven with balanced inputs. Output taken from the 8-ohm connectors unless otherwise noted.
• This amplifier does not invert polarity.
• AC line current draw at idle: 4.29A.
• Input impedance @ 1kHz
  • Unbalanced inputs: 125k ohms.
  • Balanced inputs: 263k ohms.
• Output impedance at 50Hz: 1.1 ohms.
• Input sensitivity: 148.9mV.
• Gain (8-ohm load): 19.0X, 25.6dB.
• Output noise, unbalanced inputs, 8-ohm load, 1k-ohm input termination, Lch/Rch:
  • Wideband: 0.596mV, -73.5dBW / 0.625mV, -73.1dBW
  • A weighted: 0.129mV, -86.8dBW / 0.134mV, -86.5dBW
• Output noise, balanced inputs, 8-ohm load, 600-ohm input termination, Lch/Rch:
  • Wideband: 0.684mV, -72.3dBW / 0.603mV, -73.4dBW
  • A weighted: 0.142mV, -86.0dBW / 0.126mV, -87.0dBW

Power output with 1kHz test signal

• 8-ohm load at 1% THD: 115W
• 8-ohm load at 10% THD: 126W
  
  
• 4-ohm load at 1% THD: 129W
• 4-ohm load at 10% THD: 160W

General
The Audio Research VS115 is a medium-power stereo push-pull stereo tube power amplifier utilizing two pairs of 6550 output tubes per channel. Unlike the more expensive Reference 110, which does not have an internal phase inverter topology to generate the balanced push-pull drive for the output stage, and thus has to be driven from a balanced source, the VS115 has a more standard balanced differential topology that easily and naturally allows the use of balanced or unbalanced inputs.
Chart 1 shows the frequency response of the amp with varying loads. The output impedance, as judged by the closeness of spacing between the curves of open-circuit, 8-ohm, and 4-ohm loading, is reasonably low for a tube power amplifier and from this data is approximately 1 ohm. The variation of output as a function of frequency with the NHT dummy speaker load is about +0.8/-1dB.
Chart 2 illustrates how total harmonic distortion plus noise for a 1kHz test signal and SMPTE IM distortion varies with output power and output load. Typical for a tube amplifier, the amount of distortion gradually rises over most of the power range. Also typical is that distortion is higher and maximum power before clipping is greater for 4-ohm loading.
Total harmonic distortion plus noise as a function of frequency at several different power levels is plotted in Chart 3. The amount of rise in distortion at high frequencies is admirably low, although, as is typical of tube power amplifiers with output transformers, there is some increase in distortion at low frequencies.
Damping factor versus frequency is shown in Chart 4. In this design, the damping factor stays relatively constant out to a higher frequency than is usual, some 2-3kHz.
A spectrum of the harmonic distortion and noise residue of a 10W 1kHz test signal is plotted in Chart 5. The amount of AC-line harmonics is relatively low in amplitude but numerous in number. As is frequently the case with many amplifiers tested, there are some AC-line harmonic intermodulation components on either side of the nulled-out test-signal fundamental. The principal signal harmonics are second and third with the remaining visible harmonics some 40dB below the level of the second and third harmonics.
As an aside, I listened to this amp with my Genesis Advanced Technologies 6.1 speakers -- as I do with most of the stereo amps I measure for SoundStage! I found it to be outstanding in its easy ability to make music sound believable and present in my listening room. It offers great detail and resolution without attendant harshness or edginess.

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

(line up at 1W 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
Cyan line: 100W
Blue line: 30W
Magenta line: 10W
Red line: 1W

Damping factor = output impedance divided into 8

1kHz signal at 10W into an 8-ohm load

• 测量是在120V交流与平衡输入与线路电压驱动两个通道。 输出取自8欧姆连接器，除非另有说明。
• 该放大器的极性不能倒置。
• 交流线电流消耗在空闲：4.29A。
• @ 1kHz的输入阻抗
  • 非平衡输入：125k欧姆。
  • 平衡输入：263k欧姆。
• 在50Hz输出阻抗：1.1欧姆。
• 输入灵敏度：148.9mV。
• 增益（8欧姆负载）：19.0X，二十五点六分贝。
• 输出噪声，非平衡输入，8欧姆负载，1K的欧姆输入终端，廖创兴/ Rch的：
  • 宽带：0.596mV，- 73.5dBW / 0.625mV，- 73.1dBW
  • A加权：0.129mV，- 86.8dBW / 0.134mV，- 86.5dBW
• 输出噪声，平衡输入，8欧姆负载，600欧姆的输入终端，廖创兴/ Rch的：
  • 宽带：0.684mV，- 72.3dBW / 0.603mV，- 73.4dBW
  • A加权：0.142mV，- 86.0dBW / 0.126mV，- 87.0dBW

功率输出1kHz的测试信号

• 8欧姆负载，1％总谐波失真：115W
• 8欧姆负载为10％总谐波失真：126W
  
  
• 4欧姆负载，1％总谐波失真：129W
• 4欧姆负载为10％总谐波失真：160瓦

一般
音频研究VS115是一个中等功率的立体声推挽立体声功放管利用两声道输出管，每6550对。 不同的是更昂贵的参考110，它不具有内部相逆变器拓扑生成平衡推挽式输出级的驱动器，因此必须从平衡源驱动，VS115有一个更标准的平衡差分拓扑结构，轻松，自然使平衡或不平衡投入使用。
图1显示了用不同的负载放大器的频率响应。 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，是合理的管功率放大器并从这个数据低大约为1欧姆。 对输出的频率与莱科萨斯虚拟扬声器负载功能变化约为0.8 / - 1dB的。
图2说明了总谐波失真加为1kHz的测试信号和SMPTE噪声的IM失真输出功率与输出负载变化。 为管放大器典型，失真量逐渐上升以上的功率范围最大。 典型的是，失真也较高，削波前的最大功率为4欧姆负荷更大。
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。 在高频率的增加量是令人钦佩的失真低，虽然，因为是用输出变压器管功率放大器的典型，有一定的失真在低频率的增加。
阻尼频率因子与图4所示。 在这个设计中，阻尼系数保持相对恒定出较高的频率高于往常，约2 - 3kHz。
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。 在交流线路的谐波量相对较低幅度，但数量众多。 由于经常与测试了放大器的情况下，也有一些交流线路两侧的清零出测试侧谐波互调信号的基本组成部分。 主要是第二谐波信号，并与一些低于40dB的第二和第三级谐波谐波可见其余的三分之一。
顺便说一句，我听了这个放大器与我创世纪先进技术6.1喇叭-因为我是做测量与大多数的立体声放大器，我的 ！声场 ，我发现这样做是为了突出其易于能力做出可信的和现在的音乐之声我的听音室。 它提供了服务员生硬或急躁和决议不很详细。

• Measurements were made with 120V AC line voltage.
• Output tube plate current adjusted to 65mA per tube when warmed up.
• Power output and distortion plotted with both channels driven.
• Gain: 18.3x, 25.2dB.
• Output noise, 8-ohm load, 1k-ohm input termination: wideband 0.40mV, -77.0dBW; A weighted 0.088mV, -90.1dBW.
• AC line current draw at idle: 1.9A.
• Output impedance at 50Hz: 0.89 ohms.
• This amplifier does not invert polarity.

Power output with 1kHz test signal

• 8-ohm load at 1% THD: 50W
• 8-ohm load at 10% THD: 58W
  
  
• 4-ohm load at 1% THD: 33W
• 4-ohm load at 10% THD: 70W
  
  
• 16-ohm load at 1% THD: 33W
• 16-ohm load at 10% THD: 38W

General
Measurement results for this design are typical of other well designed similar powered units. As can be seen in Chart 1, output regulation with load change is reasonable and the response variation with the NHT dummy speaker load is within +/- 0.9dB over the audio range. High-frequency bandwidth with a resistive load is about 50kHz. The tendency to peak with an open circuit load could possibly give a slight high frequency rise above 10kHz with speakers with a high frequency increasing impedance load -- typical of most dome tweeters. Harmonic distortion is reasonably low in the critical "first watt" region for 8-ohm and higher loading on the 8-ohm tap, but does increase with 4-ohm loading. On the other hand, 4-ohm loading on the 8-ohm tap does increase the power output at onset of clipping from 50 to 60 watts. While the 16-ohm power on the 8-ohm tap is down to about 28 watts, the overall matching of the output transformer to favor some power increase with low loading on an output tap is a good choice. The amount of distortion rise with frequency in Chart 3 is quite typical of many power amplifiers, both tube and solid state. In the spectrum of harmonic distortion residue of a 1kHz signal at the 10W power level in Chart 5, the odd harmonics are dominant with the even harmonics quite a bit lower indicating good push-pull balance. Although the magnitude of the AC line harmonics is similar to other amplifiers, the noise floor is quite low between the harmonics. Of interest, and technically not desirable, is the presence of a number of 120Hz spaced sidebands about the nulled out fundamental 1kHz signal. The damping factor in Chart 4 stays up at low frequencies but does start to decrease above 1kHz, again typical of many power amplifiers both tube and solid state.

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

(line up at 20W to determine lines)
Top line: 8-ohm SMPTE IM
Second line: 4-ohm on 8-ohm tap THD+N
Third line: 16-ohm on 8-ohm tap THD+N
Bottom line: 8-ohm on 8-ohm tap THD+N

8-ohm output loading on 8-ohm tap
Green line: 50W
Cyan line: 30W
Blue line: 10W
Red line: 1W

Damping factor = output impedance divided into 8

1kHz signal at 10W into an 8-ohm load

• 测量是用120V交流电压。
• 管板输出电流调整到每管六十五毫安时热身。
• 输出功率和失真策划既带动渠道。
• 增益：18.3x，二十五点二分贝。
• 输出噪声，8欧姆负载，1K的欧姆输入终端：宽带0.40mV，- 77.0dBW，一个加权0.088mV，- 90.1dBW。
• AC线在空闲电流消耗：1.9A。
• 在50Hz输出阻抗：0.89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％总谐波失真率：50W
• 8欧姆负载为10％总谐波失真：58W
  
  
• 4欧姆负载，1％总谐波失真：33W
• 4欧姆负载为10％总谐波失真功率：70W
  
  
• 16欧姆负载，1％总谐波失真：33W
• 16欧姆负载为10％总谐波失真：38W

一般
这种设计的测量结果是其他类似的供电单位精心设计的典型。 正如在图1所示，输出负载的变化规律是合理的，与莱科萨斯虚拟扬声器负载响应变化在+ / - 在音频范围0.9分贝。 高频电阻负载与带宽约为50kHz的。 峰的倾向开路负载可能可能作出轻微高于10kHz的高频带扬声器的上升，越来越高阻抗负载频率 - 最典型的圆顶高音。 谐波失真是合理的关键“第一瓦”地区为8欧姆和8欧姆的自来水更高的负载低，但与4欧姆负载量的增加。 另一方面，4欧姆的8欧姆自来水装入不能增加，从50到60瓦的功率输出削波。 虽然在8欧姆抽头16欧姆功率下降到约28瓦，输出变压器的整体配套赞成有的上自来水低负荷输出功率的增加是一个不错的选择。 的失真与图3频率的上升量是相当多功率放大器，既管和固态的典型。 在对一个1kHz信号谐波失真，在10W的功率水平图5残谱，占主导地位的奇次谐波与偶次谐波表示良好的推拉式平衡相当低一点。 虽然AC线谐波幅度是类似于其他放大器，噪音相当低地板之间的谐波。 有趣的是，和技术上并不理想，是一个关于清零了120Hz的基本1kHz的信号间隔边带增多。 在图4阻尼系数熬夜低频但上述1kHz时开始下降，再次许多功率放大器管道和固态的典型。

• Measurements were made at 120V AC line voltage and on the 8-ohm outputs. Both channels driven with balanced input. Measurements made on the left channel unless otherwise noted.
• This amplifier does not invert polarity.
• AC line current draw at idle: 4.4A.
• Input impedance @ 1kHz: 260k ohms.
• Output impedance at 50Hz: 0.73 ohms.
• Gain (8-ohm load): 16.0X, 24.1dB.
• Output noise, 8-ohm load, 600-ohm input termination, Lch/Rch:
  • wideband: 0.24mV, -81.4dBW / 0.29mV, -79.8dBW
  • A weighted: 0.05mV, -95.1dBW / 0.14 mV, -86.1dBW

Power output with 1kHz test signal

• 8-ohm load at 1% THD: 107W
• 8-ohm load at 10% THD: 129W
  
  
• 4-ohm load at 1% THD: 102W
• 4-ohm load at 10% THD: 135W

General
The Audio Research Reference 110 is a medium-power stereo push-pull tube-based power amplifier utilizing two pairs of 6550 output tubes per channel. This unit is most unusual in vacuum-tube power-amplifier design in that it has no phase inverter and depends on receiving a balanced input signal for the output stage push-pull action. Pity the person who might use single-ended RCA female-to-XLR male adapters with pin 3 (minus phase) grounded, as is usual. I did that in my initial testing and found out that the amp responded as a single-ended amplifier putting out about 20 watts per channel at 10% distortion! Needless to say, when driven with a balanced input signal, the amplifier behaved properly. Checking with Audio Research, I found out that all of the Reference-series tube power amplifiers were designed this way. I guess there is something to be said for circuit simplification by not having a phase inverter if it is known that the amp will always be driven by a balanced preamp, which the Audio Research Reference 3 is.
Chart 1 shows the frequency response of the amp with varying loads. The output impedance, as judged by the closeness of spacing between the curves of open-circuit, 8-ohm, and 4-ohm loading, is reasonably and acceptably low for a tube power amplifier. With the NHT dummy speaker load, the variation is better than +/-1dB. One thing to note, though: There is a noticeable gentle roll-off in the audio range starting at about 500Hz with the 4-ohm loading. This is also present with the 8-ohm loading to a lesser degree and not quite noticeable in the chart with the usual scale factor that I use. This, for a perfectly flat speaker load, would have the potentially audible effect of a softening of the highs or, to put it another way, give a little more weight to the lower midrange – generally a good thing, as many amplifiers are a little too thin in this region.
Chart 2 illustrates how total harmonic distortion plus noise vs. power varies for 1kHz and SMPTE IM test signals and amplifier output load. Of interest, this amplifier’s general distortion characteristic is typical of many tube amplifiers and is one of continuously increasing distortion with increasing power. As is the case with most power amplifiers, this one puts out more power, but not much more, into a 4-ohm load.
Total harmonic distortion plus noise as a function of frequency at four different power levels is plotted in Chart 3. The amount of rise in distortion at high frequencies is admirably low, although there is the typical rise in distortion at low frequencies due to the characteristics of the output transformers.
Damping factor vs. frequency is shown in Chart 4. This curve has an unusual shape and, in fact, looks somewhat like the shape of the 4-ohm frequency response. It makes me wonder if this was a deliberate design aspect of the Reference 110.
A spectrum of the harmonic distortion and noise residue of a 10W 1kHz test signal is plotted in Chart 5. The principal signal harmonics are the second and third with all higher harmonics some 40dB or so lower. AC-line harmonics are low, although there are some line-harmonic-related sidebands around the nulled-out 1kHz test-signal fundamental -- something I have seen in quite a few of the power amplifiers that I have tested, but not all of them.

Red line: open circuit
Magenta line: 8-ohm load
Blue line: 4-ohm load
Cyan line: NHT dummy-speaker 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
Cyan line: 100W
Blue line: 30W
Magenta line: 10W
Red line: 1W

Damping factor = output impedance divided into 8

1kHz signal at 10W into an 8-ohm load

• 测量是在120V交流线路电压和8欧姆输出。 两个通道驱动的平衡输入。 测量就左声道，除非另有说明。
• 该放大器的极性不能倒置。
• AC线在空闲电流消耗：4.4A。
• @ 1kHz的输入阻抗：26万欧姆。
• 在50Hz输出阻抗：0.73欧姆。
• 增益（8欧姆负载）：16.0X，24.1分贝。
• 输出噪声，8欧姆负载，600欧姆的输入终端，廖创兴/ Rch的：
  • 宽带：0.24mV，- 81.4dBW / 0.29mV，- 79.8dBW
  • A加权：0.05mV，- 95.1dBW / 0.14毫伏，- 86.1dBW

功率输出1kHz的测试信号

• 8欧姆负载，1％总谐波失真：107W
• 8欧姆负载为10％总谐波失真：129W
  
  
• 4欧姆负载，1％总谐波失真：102W
• 4欧姆负载为10％总谐波失真：135W

一般
音频研究参考110是一个中等功率的立体声推挽管为基础的功率放大器利用两个6550管对每个通道的输出。 这个单位是最真空管功率放大器设计，它没有任何不寻常的三相逆变器和接收输出级推挽行动的平衡式输入信号而定。 可怜的人谁可能使用引脚3（减期）接地单端RCA的女性对男性的XLR适配器，如往常。 我这样做，在我最初的测试，发现该放大器为单端将达到10％失真约20瓦每声道放大器的回应！ 不用说，当一个平衡输入信号驱动时，放大器的表现正常。 与音频的研究检查，我发现了参考系列管功率放大器都是这样设计的。 我想有些事情是为电路简化表示，没有一个三相逆变器，如果它是已知的放大器将永远是一个平衡的放大器，而音频驱动的研究参考文献3。
图1显示了用不同的负载放大器的频率响应。 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，是合理和可以接受的管功率放大器低。 随着莱科萨斯虚拟扬声器负载，变异优于+ / - 1dB的。 有一点要注意，虽然：有一个显着温柔的滚降约在音频与4欧姆开始装载500Hz的范围。 这也是目前与8欧姆的负载量，在较小的程度，而不是完全在与通常的比例因子，我使用图表明显。 这对于一个完全平坦的扬声器负载，将有一个高点，或软化发声效果可能以另一种方式，给多一点的重量到较低的中频 - 通常是一件好事，因为许多放大器都有点太瘦了在这一地区。
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。 有趣的是，该放大器的一般特点是许多失真管放大器的典型，是不断扩大与日益增加的电力失真之一。 如同大多数功放的情况下，这个人把更多权力，但没有更多的，为4欧姆负载。
总谐波失真加为四​​个不同的频率噪声功率水平的功能是在图3所示。 在高频率的增加量是令人钦佩的失真低，虽然是在低频失真典型上升由于输出变压器的特点。
阻尼随频率变化的因素是列于图4。 这条曲线有一个不寻常的形状，而事实上，看起来有点像在4欧姆频率响应的形状。 这让我怀疑这是一起蓄意的参考110的设计方面。
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。 主要是第二谐波信号和所有40dB的高次谐波一些低三分之一左右。 交流线路谐波低，虽然周围有清零输出1kHz的测试信号的基本部分线路谐波相关的边带 - 这是我已经在相当多的权力，我已经测试放大器少看到的，但不是全部他们。

• Measurements were made at 120V AC line voltage with both channels being driven. All measurements made with "timbre" control in mid position unless otherwise noted.
• Gain: 4.25x, 12.8dB.
• Output noise, 8-ohm load, unbalanced input, 1k-ohm input termination: wideband 0.292mV, -79.7dBW; A weighted 0.040mV, -97.0dBW.
• AC line current draw at idle: timbre control counterclockwise, 0.86A; timbre control at mid rotation, 1.0A; timbre control clockwise, 1.37A.
• Output impedance at 50Hz: 3.1 ohms.
• This amplifier inverts polarity.

Power output with 1kHz test signal

• 8-ohm load at 1% THD: 0.75W
• 8-ohm load at 10% THD: 14.6W
  
  
• 4-ohm load at 1% THD: 0.17W
• 4-ohm load at 10% THD: 8.7W

General
The Audiopax Stereo Eighty Eight is a low-/medium-powered single-ended tube amplifier utilizing a single KT88 output tube in each channel. The design is unusual in that it has a control for adjusting the "timbre" of the sound for different speakers and situations. This control appears to vary the quiescent current in the output tube. It turns out that one measurable effect of this control is to vary the damping factor of the output. Gain and distortion characteristics are also affected. Gain of the unit is somewhat lower than usual for power amplifiers. Rated power is 15W into an 8-ohm load.
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 of a typical value for tube amplifiers. The variation with the NHT dummy load in the audio range is on the order of +/-2dB.
Chart 2 illustrates how total harmonic distortion plus noise vs. power varies for 1kHz and SMPTE IM test signals and amplifier output load. This design, with its single output connection for speaker load, puts out about the same power into 4- or 8-ohm loads, although the distortion is greater with 4-ohm loading.
Total harmonic distortion plus noise as a function of frequency at several different power levels is plotted in Chart 3. The amount of rise in distortion at high frequencies is admirably low, but the increase in distortion at low frequencies is quite pronounced.
As an illustration of one of the parameters that are affected by the timbre control, damping factor is plotted in Chart 4 as a function of the timbre control set at counterclockwise, mid-rotation, and clockwise positions. This measurement was done at a much lower current (.125A) than the usual 1A in order to maintain signal linearity at the lowest timbre setting.
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 very low, and the signal harmonic spectrum has the desirable characteristic of tapering off as the harmonic number increases.

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

(line up at 2W 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
Cyan line: 14W
Blue line: 10W
Magenta line: 5W
Red line: 1W

Damping factor = output impedance divided into 8
Red line: timbre control fully clockwise
Magenta line: timbre control at mid position
Blue line: timbre control fully counterclockwise

1kHz signal at 10W into an 8-ohm load

• 测量是在120V交流线路电压均为驱动渠道。 所有的测量作出的“音色”在中间位置的控制，除非另有说明。
• 增益：4.25x，十二点八分贝。
• 输出噪声，8欧姆负载，不平衡输入，1K的欧姆输入终端：宽带0.292mV，- 79.7dBW，一个加权0.040mV，- 97.0dBW。
• 交流线电流消耗，在闲置：音色控制逆时针，0.86A;在旋转中，1.0A的音色控制音色控制顺时针，1.37A。
• 在50Hz输出阻抗：3.1欧姆。
• 该放大器颠倒极性。

功率输出1kHz的测试信号

• 8欧姆负载，1％总谐波失真：0.75W
• 8欧姆负载为10％总谐波失真：14.6W
  
  
• 4欧姆负载，1％总谐波失真：0.17W
• 4欧姆负载为10％总谐波失真：8.7W

一般
该Audiopax立体声八十low-/medium-powered 8是一个单端电子管放大器，利用一个单一的KT88在每个通道的输出管。 其设计的特别之处在于它有一个调整对不同声音的喇叭和情况“音色”控制。 这种控制似乎有所不同，在输出管静态电流。 事实证明，这种控制的一个可衡量的效果是改变输出的阻尼因素。 增益和失真特性也受到影响。 单位增益略低于功率放大器通常较低。 额定功率为15瓦到8欧姆负载。
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，如之间开路，8欧姆，4欧姆负荷曲线间距接近判断，是一个管放大器的典型值。 与音频范围内的莱科萨斯假负载的变化是建立在+ / - 2dB的秩序。
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。 这种设计，其单一的扬声器负载，输出接口，拿出大约相同的功率为4 - 或8欧姆负载，虽然失真是4欧姆负荷更大。
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。 在高频率的增加量是令人钦佩的失真低，但在低频率的增加是非常明显的失真。
作为对由该音色控制受影响的参数之一画像，阻尼因素是绘制于图4是在逆时针，中旋转设置音色控制功能，并顺时针立场。 这种测量方法做以低得多的电流（0.125一），比通常的第1A，以保持信号在音色设定最低的线性关系。
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 -线路谐波幅度非常低，信号谐波频谱具有逐渐变细的谐波数增加了可取的特点。

• Measurements were made at 120V AC line voltage with one channel driven (this is a mono amplifier) using the balanced inputs and an Audio Precision AUX-0025 measurement filter unless otherwise noted.
• This amplifier does not invert polarity.
• AC line current draw at idle: 0.26A.
• Input impedance @ 1kHz
  • Balanced input: 8.7k ohms.
  • Unbalanced input: 11.0k ohms.
• Output impedance at 50Hz: 0.008 ohms.
• Gain (8-ohm load): 23.3X, 27.4dB.
• Output noise, 8-ohm load, balanced input, 600-ohm input termination: wideband without A/P AUX-0025 filter 1.29V, -6.8 dBW; wideband 2.07mV, -62.7 dBW; A weighted 0.091 mV, -89.8 dBW.

Power output with 1kHz test signal

• 8-ohm load at 1% THD: 597W
• 8-ohm load at 10% THD: 500W
  
  
• 4-ohm load at 1% THD: 1172W
• 4-ohm load at 10% THD: 1152W

General
The Bel Canto e.One REF1000 is a high-power switching design utilizing the ICEpower 1000ASP module. This marks a departure for Bel Canto, as I believe that their earlier amplifier designs used Tripath circuitry -- quite different from the ICEpower approach.
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 up to about 2-3kHz. Above this, the output impedance has increased to where one can see some variation with load. Above 3kHz, the variation with the NHT dummy speaker load is of the order of perhaps +/-0.4dB. As switching amps go, the ICEpower modules have pretty good high-frequency response control above the audio range with varying loads.
Chart 2 illustrates how total harmonic distortion plus noise vs. power varies for 1kHz and SMPTE IM test signals with 4- and 8-ohm loads. As can be seen, attainable power is greater for the 4-ohm load, as is usual for most power amplifiers. Amount of distortion in Chart 2 is quite reasonable.
Total harmonic distortion plus noise as a function of frequency at several different power levels is plotted in Chart 3. This amplifier does exhibit quite a bit of rise in high-frequency distortion starting below 1kHz. At the higher power levels, it starts to lose it above 10kHz. There is also some rise in distortion at low frequencies.
Damping factor vs. frequency is shown in Chart 4 and is very high at low frequencies but declines precipitously around a few hundred Hz -- not unusual behavior for amplifiers with very high damping factors at low frequencies.
A spectrum of the harmonic distortion and noise residue of a 10W 1kHz test signal is plotted in Chart 5. The amount of AC-line harmonics is admirably low. The signal frequency harmonics are dominantly of odd order.

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

4-ohm output loading
Green: 900W
Cyan line: 500W
Blue line: 100W
Magenta line: 10W
Red line: 1W

Damping factor = output impedance divided into 8

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

• 测量是在120V交流电压驱动与一个通道（这是一个单声道放大器）使用平衡输入和音频精密辅助- 0025测量滤波器，除非另有说明。
• 该放大器的极性不能倒置。
• 交流线电流消耗在空闲：0.26A。
• @ 1kHz的输入阻抗
  • 平衡输入：8.7k欧姆。
  • 不平衡输入：11.0k欧姆。
• 在50Hz输出阻抗：0.008欧姆。
• 增益（8欧姆负载）：23.3X，二十七点四分贝。
• 输出噪声，8欧姆负载，平衡输入，600欧姆的输入端接：没有的A / P辅助- 0025宽带滤波器1.29V，-6.8无国界医生组织，宽带2.07mV，-62.7无国界医生组织，一个加权0.091 mV时，-89.8无国界医生组织。

功率输出1kHz的测试信号

• 8欧姆负载，1％总谐波失真：597W
• 8欧姆负载为10％总谐波失真：500瓦
  
  
• 4欧姆负载，1％总谐波失真：1172W
• 4欧姆负载为10％总谐波失真：1152W

一般
美声唱法e.One REF1000是一种高功率开关设计，利用ICEpower 1000ASP模块。 这标志着美声唱法的离开，因为我相信他们早期的放大器电路设计中使用还在Tripath - 不同于ICEpower方法不同。
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，是相当低了约2 - 3kHz。 高于此，输出阻抗已增至这里人们可以看到一些与负荷变化。 以上3kHz，与莱科萨斯虚拟扬声器负载的变化也许是+ / - 0.4dB的秩序。 作为开关放大器去，ICEpower模组有很好的高频率高于音频范围变负荷响应控制。
图2说明了总谐波失真加噪声与功率为1kHz的变化，并与4 SMPTE的即时测试信号 - 和8欧姆的负载。 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。 在图2失真量也相当合理。
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。 该放大器也表现出相当高频率失真低于1kHz时开始上升了一点。 在更高的功率水平，它开始失去它上面10kHz的。 也有一些失真低频率不断上升。
阻尼随频率变化的因素是在图4所示是急剧周围几百赫兹的频率非常低，但跌幅高 - 不寻常行为的放大器在低频率非常高阻尼因素。
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。 在交流线路的谐波量低令人钦佩。 信号的频率谐波是奇数阶为主。

• Measurements were made at 120V AC line voltage with both channels being driven. Measurements made on the left channel and the unbalanced inputs unless otherwise noted.
• This amplifier does not invert polarity.
• AC line current draw at idle: 0.37A.
• Input impedance @ 1kHz: 9.9k ohms.
• Output impedance at 50Hz: 0.026 ohms.
• Input sensitivity for 1W output into 8 ohms:
  • 1V sensitivity: 99.6mV
  • 2V sensitivity: 197.8mV
• Gain (8-ohm load), unbalanced and balanced inputs:
  • 1V sensitivity: 28.4X, 29.1dB.
  • 2V sensitivity: 14.3X, 23.1dB.
• Output noise, 8-ohm load, unbalanced input, 1k-ohm input termination, Lch/Rch:
  • 1V sensitivity: wideband - 0.21mV, -82.6dBW / 0.18mV, -83.9dBW
  • 2V sensitivity: wideband - 0.18mV, -83.9dBW / 0.13mV, -86.8dBW
  • 1V sensitivity: A weighted - 0.11mV, -88.2dBW / 0.046mV, -95.8dBW
  • 2V sensitivity: A weighted - 0.10mV, -89.0dBW / 0.032mV, -98.9dBW
• Output noise, 8-ohm load, balanced input, 600-ohm input termination, Lch/Rch:
  • 1V sensitivity: wideband - 0.29mV, -79.8dBW / 0.28mV, -80.1dBW
  • 2V sensitivity: wideband - 0.21mV, -82.6dBW / 0.16mV, -85.0dBW
  • 1V sensitivity: A weighted - 0.11mV, -88.2dBW / 0.069mV, -92.3dBW
  • 2V sensitivity: A weighted - 0.10mV, -89.0dBW / 0.040mV, -97.0dBW

Power output with 1kHz test signal

• 8-ohm load at 1% THD: 127W
• 8-ohm load at 10% THD: 163W
  
  
• 4-ohm load at 1% THD: 213W
• 4-ohm load at 10% THD: 235W

General
The Bryston 2B SST C-Series is a medium-power solid-state stereo power amplifier, the lowest-powered unit in Bryston’s SST C-Series line.
Chart 1 shows the frequency response of the amp with varying loads. The high-frequency response is moderately wide with an approximate 3dB down point of 100kHz. Output impedance, as judged by the closeness of spacing between the curves of open-circuit, 8-ohm, and 4-ohm loading, is quite low in the audio band. The usual NHT dummy-load curve is not shown as the variations in the response would not display. The variation with the NHT dummy load in the audio range is of the order of +/-0.05dB -- a negligible amount.
Chart 2 illustrates how total harmonic distortion plus noise vs. power varies for 1kHz and SMPTE IM test signals and amplifier output load. The amount of distortion is low right up to clipping --- the behavior of most solid-state power amplifiers. The distortion performance was essentially identical with unbalanced and balanced connections.
Total harmonic distortion plus noise as a function of frequency at several different power levels is plotted in Chart 3 for 4-ohm loading. The amount of rise in distortion at low and high frequencies is admirably low, except at the 180W level where distortion started to rise abruptly below 20Hz, most likely due to power-supply limitations. This didn’t happen with the 8-ohm loads at the rated 100W power output.
Damping factor vs. frequency is shown in Chart 4 and is of a value and nature typical of many solid-state amplifiers, being high up to about 1kHz and then rolling off with frequency.
The left channel of this unit had somewhat more power-supply line harmonics due to rectifier conduction-pulse ground currents than the quieter right channel. Therefore, the spectrum of both channels is shown in charts 5A and 5B for a 10W 1kHz test signal with 8-ohm loading. As can be seen, the left-channel spectrum has many line harmonics that extend way up into the test-signal area, whereas the right-channel spectrum is more normal looking with low amounts of line harmonics and a tapering-off spectrum of test-signal harmonics.

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

(line up at 70W to determine lines)
Top line: 4-ohm THD+N
Second line: 8-ohm SMPTE IM
Third line: 8-ohm THD+N
Bottom line: 4-ohm SMPTE IM

4-ohm output loading
Grey line: 180W
Cyan line: 100W
Blue line: 30W
Magenta line: 10W
Red line: 1W

Damping factor = output impedance divided into 8

5A - left channel

1kHz signal at 10W into an 8-ohm load

5B - right channel

1kHz signal at 10W into an 8-ohm load

• 测量是在120V交流线路电压均为驱动渠道。 测量就左声道，除非另有说明，非平衡输入。
• 该放大器的极性不能倒置。
• 交流线电流消耗在空闲：0.37A。
• @ 1kHz的输入阻抗：9.9k欧姆。
• 在50Hz输出阻抗：0.026欧姆。
• 1W的输入灵敏度为8欧姆的输出：
  • 1V的灵敏度：99.6mV
  • 2V的灵敏度：197.8mV
• 增益（8欧姆负载），不平衡和平衡输入：
  • 1V的灵敏度：28.4X，29.1分贝。
  • 2V的灵敏度：14.3X，二十三点一分贝。
• 输出噪声，8欧姆负载，不平衡输入，1K的欧姆输入终端，廖创兴/ Rch的：
  • 1V的灵敏度：宽带 - 0.21mV，- 82.6dBW / 0.18mV，- 83.9dBW
  • 2V的灵敏度：宽带 - 0.18mV，- 83.9dBW / 0.13mV，- 86.8dBW
  • 1V的灵敏度：A加权 - 0.11mV，- 88.2dBW / 0.046mV，- 95.8dBW
  • 2V的灵敏度：A加权 - 0.10mV，- 89.0dBW / 0.032mV，- 98.9dBW
• 输出噪声，8欧姆负载，平衡输入，600欧姆的输入终端，廖创兴/ Rch的：
  • 1V的灵敏度：宽带 - 0.29mV，- 79.8dBW / 0.28mV，- 80.1dBW
  • 2V的灵敏度：宽带 - 0.21mV，- 82.6dBW / 0.16mV，- 85.0dBW
  • 1V的灵敏度：A加权 - 0.11mV，- 88.2dBW / 0.069mV，- 92.3dBW
  • 2V的灵敏度：A加权 - 0.10mV，- 89.0dBW / 0.040mV，- 97.0dBW

功率输出1kHz的测试信号

• 8欧姆负载，1％总谐波失真：127W
• 8欧姆负载为10％总谐波失真：163W
  
  
• 4欧姆负载，1％总谐波失真：213W
• 4欧姆负载为10％总谐波失真：235W

一般
海温的Bryston乙C系列是一个中等功率固态立体声功率放大器，在Bryston的海温C系列线最低的供电单位。
图1显示了用不同的负载放大器的频率响应。 高频率响应宽，适度降低100kHz的点近似3dB的。 输出阻抗，如之间开路，8欧姆，4欧姆负荷曲线间距接近判断，是相当低的音频频带。 通常莱科萨斯假负载曲线没有显示如响应不会显示的变化。 与音频范围内的变化是莱科萨斯假负载的+ / -0.05分贝秩序 - 微不足道。
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。 失真的数量很少直到剪辑---大多数固态功率放大器的行为。 失真的表现基本上是平衡与不平衡和连接相同。
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4欧姆负载。 在低失真和高增长量是令人钦佩的频率低，除了在180瓦水平，失真开始崛起低于20Hz的，最有可能因电力供应的限制。 这并没有发生与在额定100W功率输出的8欧姆负载。
阻尼系数与频率是在图4所示，并与自然的价值，许多固态放大器，典型的是，被高至约1kHz的频率，然后滚动关闭。
该单位的左声道有较为电源线由于整流谐波比安静的右声道传导电流脉冲地面。 因此，这两个频道频谱显示在图表5A和5B 1kHz时为10W的8欧姆负载试验信号。 可以看出，左边的通道频谱谐波，有许多行一路延伸到测试信号区，而右声道是比较正常的频谱与低量的线路谐波​​和逐渐减少的测试过的频谱看，信号的谐波。

• Measurements were made with 120V AC line voltage with both channels driven, input gain switch set to 1V, driving the unbalanced inputs unless otherwise noted.
• Gain, unbalanced input: 28.7x, 29.5dB (with input switch set to 1V)
• Output noise, 8-ohm load, unbalanced input, 1k-ohm input termination: wideband 0.260mV, -80.7dBW; A weighted 0.067mV, -92.5dBW.
• Output noise, 8-ohm load, balanced input, 600-ohm input termination: wideband 0.307mV, -79.3dBW; A weighted 0.083mV, -90.6dBW.
• AC line current draw at idle: 1.0A.
• Output impedance at 50Hz: 0.011 ohms.
• This amplifier does not invert polarity.

Power output with 1kHz test signal

• 8-ohm load at 1% THD: 336W
  
  
• 4-ohm load at 1% THD: 528W

General
The Bryston 4B SST is a medium-/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 in the audio range is 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 modest -- a good thing. Damping factor versus frequency is shown in Chart 4. A spectrum of the harmonic distortion and noise residue is plotted in Chart 5. The magnitude of the AC line harmonics are low for this amplifier. The test signal harmonics are both even and odd harmonic with the odd harmonics dominating the total harmonic sum. The higher-order harmonics quickly decline into the noise level.

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

4-ohm output loading
Cyan line: 450W
Blue line: 140W
Magenta line: 20W
Red line: 2W

Damping factor = output impedance divided into 8

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

• 测量120V交流会上提出了既驱动通道，输入增益线路电压开关设置为1V，推动非平衡输入，除非另有说明。
• 增益，不平衡输入：28.7x，二十九点五分贝（与输入开关设定到1V）
• 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0.067mV，- 92.5dBW。
• 输出噪声，8欧姆负载，平衡输入，600欧姆的输入端接：宽带0.307mV，- 79.3dBW，一个加权0.083mV，- 90.6dBW。
• AC线在空闲电流消耗：1.0A的。
• 在50Hz输出阻抗：0.011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：336W
  
  
• 4欧姆负载，1％总谐波失真：528W

一般
海温的Bryston 4B条是medium-/high-power固态与典型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。 与音频范围内的莱科萨斯假负载的变化可以忽略不计。 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。 在高频率的增加量是适度的变形 - 一件好事。 阻尼频率因子与图4所示。 阿的谐波失真和噪声残留谱绘制于图5。 交流线路的谐波幅度较低这个放大器。 测试信号谐波都是奇数和偶数的总和占据了总谐波谐波的奇次谐波。 在高次谐波迅速下降到噪音水平。

• Measurements were made at 120V AC line voltage with both channels being driven; measurements made on left channel unless otherwise noted.
• This integrated amplifier does not invert polarity.
• AC line current draw:
  • at idle: 0.76A
  • in standby: 0.00A
• Input sensitivity for 1W output into 8 ohms, volume at maximum: 24.8mV
• Input impedance @ 1kHz: 47.6k ohms
• Output impedance at 50Hz: 0.026 ohms
• Gain, output voltage divided by input voltage, volume at maximum: 114.2X, 41.2dB
• Output noise, 8-ohm load, 1k-ohm input termination, Lch/Rch
  • Volume control at reference position
    • wideband: 0.70mV, -72.1dBW / 0.66mV, -72.6dBW
    • A weighted: 0.37mV, -77.7dBW / 0.33mV, -78.7dBW
  • Volume control full clockwise
    • wideband: 1.86mV, -63.6dBW / 1.84mV, -63.7dBW
    • A weighted: 0.67mV, -72.5dBW / 0.65mV, -72.8dBW
  • Volume control full counterclockwise
    • wideband: 0.63mV, -73.0dBW / 0.59mV, -73.6dBW
    • A weighted: 0.36mV, -77.9dBW / 0.32mV, -78.9dBW

Power output with 1kHz test signal

• 8-ohm load at 1% THD: 140W
• 8-ohm load at 10% THD: 165W
  
  
• 4-ohm load at 1% THD: 191W
• 4-ohm load at 10% THD: 213W

General
The Bryston B100 SST is a medium-power solid-state integrated amplifier. The overall gain of this unit is on the high side for an integrated amplifier of the type so popular these days -- the kind with a passive selector switch and volume control preceding a power amplifier. The B100 SST has an active line-level preamp stage within, and the overall gain is appropriate for this topology.
Chart 1 shows the frequency response of the amp with varying loads. The high-frequency response is moderately wide with an approximate -3dB point of 80kHz. Output impedance, as judged by the closeness of spacing between the curves of open-circuit, 8-ohm and 4-ohm loading, is quite low in the audio band. The usual NHT-dummy-load curve is not shown as the variations in the response would not appear. The variation with the NHT dummy load in the audio range is less than +/-0.05dB -- a negligible amount. The frequency response was quite independent of volume-control setting. This plot was made with the reference volume-control position as set for 0.5V input to produce 5W output into an 8-ohm load.
Chart 2 illustrates how total harmonic distortion plus noise vs. power varies for 1kHz and SMPTE IM test signals and amplifier output load. Amount of distortion is satisfactorily low in this design, rising out of the noise at 10-20W.
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 admirably low -- practically non-existent.
Damping factor vs. frequency is shown in Chart 4 and is of a value and nature typical of many solid-state amplifiers, being high up to mid-hundreds of Hz and then rolling off with frequency.
A spectrum of the harmonic distortion and noise residue of a 10W 1kHz test signal is plotted in Chart 5. The magnitudes of the AC-line harmonics are low and simple, and intermodulation components of line harmonics with signal harmonics are also low. Visible signal harmonics consist of second, third, and fourth harmonics.

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

(line up at 50W to determine lines)
Top line: 8-ohm SMPTE IM
Second line: 4-ohm SMPTE IM
Third line: 8-ohm THD+N
Bottom line: 4-ohm THD+N

8-ohm output loading
Cyan line: 100W
Blue line: 30W
Magenta line: 10W
Red line: 1W

Damping factor = output impedance divided into 8

1kHz signal at 10W into an 8-ohm load

• 测量是在120V交流线路电压均为驱动渠道;在左声道，除非另有说明进行的测量。
• 这种集成放大器的极性不能倒置。
• 交流线路电流：
  • 在怠速：0.76A
  • 在待机状态：0.00A
• 1W输出的输入灵敏度为8欧姆，音量开到最大：24.8mV
• @ 1kHz的输入阻抗：47.6k欧姆
• 在50Hz输出阻抗：0.026欧姆
• 增益，输出电压的输入电压，在最大音量分为：114.2X，41.2分贝
• 输出噪声，8欧姆负载，1K的欧姆输入终端，廖创兴/ Rch的
  • 音量控制在基准位置
    • 宽带：0.70mV，- 72.1dBW / 0.66mV，- 72.6dBW
    • A加权：0.37mV，- 77.7dBW / 0.33mV，- 78.7dBW
  • 音量控制旋钮顺时针满
    • 宽带：1.86mV，- 63.6dBW / 1.84mV，- 63.7dBW
    • A加权：0.67mV，- 72.5dBW / 0.65mV，- 72.8dBW
  • 音量控制逆时针
    • 宽带：0.63mV，- 73.0dBW / 0.59mV，- 73.6dBW
    • A加权：0.36mV，- 77.9dBW / 0.32mV，- 78.9dBW

功率输出1kHz的测试信号

• 8欧姆负载，1％总谐波失真：140W的
• 8欧姆负载为10％总谐波失真：165瓦
  
  
• 4欧姆负载，1％总谐波失真：191W
• 4欧姆负载为10％总谐波失真：213W

一般
B100的海表温度的Bryston是一个中等功率固态放大器集成。 该单位的总增益为一个类型受追捧集成放大器偏高 - 与被动选择开关和音量控制功率放大器前一种。 在B100的海温有一个活跃的线路级前置阶段内，整体增益这种拓扑结构是适当的。
图1显示了用不同的负载放大器的频率响应。 高频率响应宽适度的80kHz的近似- 3dB点。输出阻抗，如之间开路，8欧姆和4欧姆负荷曲线间距接近判断，是相当低的音频频带。 通常莱科萨斯-假负载曲线不作为的反应将不会出现变化。 与音频范围内的莱科萨斯假负载变化小于+ / -0.05分贝 - 一个微不足道的金额。 频率的反应相当的音量控制设置无关。 此图写了与参考音量控制位​​置为0.5V的输入，以产生为8欧姆负载5W输出设置。
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。 令人满意的是低失真量在这个设计中，上升为10 - 20W的噪音。
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。 在高频率的增加额是令人钦佩的失真低 - 几乎不存在。
阻尼系数与频率显示在图4和第一个值和性质许多固态放大器典型的是，被高至中期的数百赫兹的频率，然后滚动关闭。
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。 在交流线路谐波的幅度线谐波低，简单，和互调分量信号谐波也较低。 可见信号谐波组成的第二，第三和第四谐波。

• Measurements were made with 120V AC line voltage with both channels driven using the unbalanced inputs.
• Gain, unbalanced input/balanced input: 28.6x, 29.1dB/28.6x, 29.1dB.
• Output noise, 8-ohm load, unbalanced input, 1k-ohm input termination: wideband 0.282mV, -80.0dBW; A weighted 0.068mV, -92.4dBW.
• Output noise, 8-ohm load, balanced input, 600-ohm input termination: wideband 0.285mV, -79.9dBW; A weighted 0.065mV, -92.8dBW.
• AC line current draw at idle: 1.44A.
• Output impedance at 50Hz: 0.0055 ohms.
• This amplifier does not invert polarity.

Power output with 1kHz test signal

• 8-ohm load at 1% THD: 224W
  
  
• 4-ohm load at 1% THD: 425W

General
The Classé Audio CA-2200 is a medium-/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 in the audio range is 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 fairly pronounced and is similar to that of many amplifiers measured.
Damping factor versus frequency is shown in Chart 4 and is unusually high.
A spectrum of the harmonic distortion and noise residue is plotted in Chart 5. The magnitude of the AC-line harmonics is low and typical of many of the amplifiers measured at BHK Labs. The test signal harmonics are both even and odd harmonic, with the odd harmonics dominating the total harmonic sum. The higher-order harmonics quickly decline into the noise level.

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: 350W
Blue line: 100W
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交流与使用非平衡输入驱动两个通道的线路电压。
• 增益，非平衡输入/平衡输入：28.6x，29.1dB/28.6x，29.1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0.282mV，- 80.0dBW，一个加权0.068mV，- 92.4dBW。
• 输出噪声，8欧姆负载，平衡输入，600欧姆的输入端接：宽带0.285mV，- 79.9dBW，一个加权0.065mV，- 92.8dBW。
• 交流线电流消耗在空闲：1.44A。
• 在50Hz输出阻抗：0.0055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：224W
  
  
• 4欧姆负载，1％总谐波失真：425W

一般
该Classé音频的CA - 2200是一种medium-/high-power固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。 与音频范围内的莱科萨斯假负载的变化可以忽略不计。
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。 在高频率的失真上升的数量也相当明显，是许多类似的测量放大器的。
阻尼频率因子与图4所示，是非常高。
阿的谐波失真和噪声残留谱绘制于图5。 将AC -线路谐波幅度很低，在实验室测量放大器的BHK许多典型。 测试信号谐波都是偶次谐波，总谐波与主宰奇次谐波的总和。 在高次谐波迅速下降到噪音水平。

• Measurements were made with 120V AC line voltage.
• Power output and distortion plotted with both channels driven.
• Test signal applied to unbalanced inputs unless otherwise noted.
• Output noise, 8-ohm load, unbalanced input, 1k-ohm input termination: wideband 0.429mV, -76.4dBW; A weighted 0.108mV, -88.4dBW.
• Output noise, 8-ohm load, balanced input, 600-ohm input termination: wideband 0.239mV, -81.5dBW; A weighted 0.113mV, -88.0dBW.
• AC line current draw at idle: 3.7A cold, 1.8A warmed up.
• Output impedance at 50Hz: 0.052 ohms.
• This amplifier does not invert polarity.

Power output with 1kHz test signal

• 8-ohm load at 1% THD: 142W
  
  
• 4-ohm load at 1% THD: 246W

General
The Coda Model 12 is a high-power solid-state design with very low output impedance and a relatively high output-stage idling current. As far as the front-panel designation of "Class A," this is most decidedly not the case. A true classic standard definition class-A amplifier at this power level would draw some 10A off the AC line to be class A up to clipping with 8-ohm loads. Unusually, the low output impedance extends way up into the ultrasonic frequency measurement limit of my Audio Precision measurement system.
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. The variation with the NHT dummy load would be about a neglible +/-0.05dB. Note that the curves track each other above the audio range, indicating the output impedance is low in this region also. 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. This amp is one of a very few in my experience that has the desirable characteristic of approximately constant amount of distortion versus frequency. Damping factor versus frequency is shown in Chart 4. Note how this is quite constant over the audio range. 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. Of note: the amount of signal harmonics are low and the higher-order products disappear rapidly.

Magenta line: open circuit
Red 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

4-ohm output loading
Red line: 2W
Magenta line: 20W
Blue line: 120W
Cyan line: 220W

Damping factor = output impedance divided into 8

1kHz signal at 10W into an 8-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。
• 测试信号施加到非平衡输入，除非另有说明。
• 输出噪声，8欧姆负载，不平衡输入，1K的欧姆输入终端：宽带0.429mV，- 76.4dBW，一个加权0.108mV，- 88.4dBW。
• 输出噪声，8欧姆负载，平衡输入，600欧姆的输入端接：宽带0.239mV，- 81.5dBW，一个加权0.113mV，- 88.0dBW。
• AC线在闲置电流：3.7A冷，1.8A热身。
• 在50Hz输出阻抗：0.052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：142W
  
  
• 4欧姆负载，1％总谐波失真：246W

一般
12的尾波模型是一种高功率固体状态非常低的输出阻抗和相对高的输出级空载电流设计。至于前面板指定的“A级”，这是最坚决并非如此。 一个真正的经典标准清晰度甲级此功率级放大器交流会抽出一些10A条线是A级到8欧姆负载裁剪。 与众不同的是，低输出阻抗一路延伸到我的超声波频率的音频精密测量系统的测量极限。
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很低。 用假负载变化莱科萨斯将约为微不足道+ / -0.05分贝。 请注意，上面的曲线轨道相互音频范围，显示，输出阻抗是在这一地区还低。 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。 这种放大器是一个非常在我的经验，具有大致相同的金额与频率失真为数不多的理想特性。 阻尼频率因子与图4所示。 请注意这是相当多的音频范围不变。 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，这其中有一个关于清零与基频和谐波这些谐波信号边带一些交流线路哼谐波丰富系列。 值得注意的是：信号谐波量低，较高阶的产品迅速消失。

• Measurements were made with 120V AC line voltage.
• Measurements were made on the left channel.
• Gain: 24.6x, 27.8dB.
• Output noise, 8-ohm load, unbalanced input, 1k-ohm input termination: wideband 0.255mV, -80.9dBW; A weighted 0.103mV, -88.8dBW.
• AC line current draw at idle: 3.6A.
• Output impedance at 50Hz: 0.98 ohms.
• This amplifier does not invert polarity.

Power output with 1kHz test signal

• 8-ohm load at 1% THD: 98W
• 8-ohm load at 10% THD: 110W
  
  
• 4-ohm load at 1% THD: 140W
• 4-ohm load at 10% THD: 160W

General
The Conrad-Johnson Premier 140 tube amp is an interesting-looking piece. Its physical layout is unusual in that the front and rear panels are on the sides relative to the enclosed transformer and capacitor cover. This amp is a stereo push-pull design rated at a nominal 140W. A potentiometer and LED indicator set output-tube idling current adjacent to each output tube.
High-frequency bandwith, as seen in Chart 1, is unusually wide for a tube design having a 3dB down point of about 140kHz. The low-frequency response holds up down to 10Hz nicely at the 1W level of the test. utput impedance is typical of many tube amplifiers, giving less than a 2dB frequency-response variation with the NHT dummy speaker load. Total harmonic distortion plus noise and SMPTE IM distortion as a function of power output and load for a test frequency of 1kHz is plotted in Chart 2. More power is delivered with the 4-ohm load as that is the default way the amp is delivered. (The amp can be configured to be optimum for 8- or 16-ohm loads.) Amount of distortion is admirably low for powers up to perhaps 10-20W, where the kernel of most music resides. Total harmonic distortion plus noise as a function of frequency at several power levels is plotted in Chart 3 for a 4-ohm load. Admirable is the relatively low amount of distortion increase at the higher frequencies. However, distortion does rise considerably below 20Hz at higher powers. The rise in distortion at low frequencies is a strong function of how closely the bias is adjusted for equal current in all four output tubes. When I first measured the left channel of this amp, the rise in distortion at low frequencies was considerably more pronounced. When I went to more carefully adjust the bias, I found that two of the four output tubes were down in current compared to the other two. When I really tweaked the bias so that the red indicator LEDs just went out at 120V AC line input for all four tubes, the performance of the left channel more closely matched that of the right channel. Damping factor vs. frequency referred to an 8-ohm load is plotted in Chart 4, and it is quite consistent over most of the audio range. In the spectral plot of distortion and noise for a 10W 1kHz signal into a 4-ohm load plotted in Chart 5, the signal distortion components are dominated by the second and third harmonics with higher-order harmonics at reduced and decreasing amplitude with frequency. As I have seen in quite a number of other amplifiers measured, there is quite a bit of 120Hz power-supply hum modulation around the suppressed fundamental 1-kHz test frequency.

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

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

4-ohm output loading
Green line: 140W
Blue line: 30W
Magenta line: 10W
Red line: 1W

Damping factor = output impedance divided into 8

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

• 测量是用120V交流电压。
• 测量了左侧通道。
• 增益：24.6x，二十七点八分贝。
• 输出噪声，8欧姆负载，不平衡输入，1K的欧姆输入终端：宽带0.255mV，- 80.9dBW，一个加权0.103mV，- 88.8dBW。
• AC线在空闲电流消耗：3.6A。
• 在50Hz输出阻抗：0.98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：98W
• 8欧姆负载为10％总谐波失真：110W
  
  
• 4欧姆负载，1％总谐波失真：140W的
• 4欧姆负载为10％总谐波失真：160瓦

一般
康拉德- 140电子管功放约翰逊总理是一个有趣的外观件。 它的物理布局是与众不同的，前后面板的两侧相对封闭的变压器和电容器盖的。 这是一个立体声放大器推挽设计在额定标称140W的。 电位器和LED指示灯设置输出管相邻的空载电流输出管。
高频带宽，如图表1所示，是一个不同寻常的宽管有3dB的下降点约140kHz设计。 低频响应容纳到在10Hz的试验1W的水平很好。 utput阻抗是许多管放大器的典型，使超过2dB的频率响应与莱科萨斯虚拟扬声器负载变化少。 总谐波失真加一个功能，输出功率为1kHz的测试频率负载噪音和SMPTE的IM失真是绘制于图2。 更多的功率传递与4欧姆负载因为这是默认方式，AMP被交付。 （该放大器可以配置为8最佳 - 。或16欧姆负载）的低失真量，是令人钦佩的权力，直至大约10 - 20W的，那里的大多数音乐的核心所在。 总谐波失真加作为频率的函数噪声功率水平在几个图3所示为一个4欧姆负载。 令人钦佩的是在较高的变形频率的增加量相对较低。 然而，不失真点起床，更高的权力大大低于20Hz的。 在低频失真的崛起是如何紧密合作，平等的偏见是当前调整，在所有四个输出管的强大功能。 当我第一次测出这功放左声道，在低频失真大大上升更为显着。 当我去更仔细地调整偏见，我发现，四个输出管二下跌目前相对于其他两个。 当我真的调整了偏差，使红色LED指示灯就一直在120V交流输入线为所有四个管，左声道的表现更密切配合，该权利的渠道。 阻尼系数与频率提到了8欧姆负载绘制于图4，这是相当一致的音频范围以上的多数。 在失真和噪声1kHz时为10W的为4欧姆负载信号的频谱图绘于图5，信号失真组件由高次谐波的二次和三次谐波主宰随频率降低，降低幅度。 正如我在其他相当多的测量放大器的数目来看，有相当多的120Hz的电源位哼调制抑制各地的基本1 kHz的测试频率。

• Measurements were made at 120V AC line voltage with both channels driven.
• This amplifier inverts polarity.
• AC line current draw
  • Plugged in: 0.02A
  • At idle: 1.65A
• Input impedance @ 1kHz: 80k ohms.
• Output impedance at 50Hz: 0.12 ohms.
• Gain (8-ohm load): 54.8X, 34.8dB.
• Output noise, 8-ohm load, 1k-ohm input termination, Lch/Rch:
  • Wideband: 0.295mV, -79.6dBW / 0.465mV, -75.7dBW
  • A weighted: 0.112mV, -88.0dBW / 0.177mV, -84.0dBW

Power output with 1kHz test signal

• 8-ohm load at 1% THD: 400W
• 8-ohm load at 10% THD: 500W
  
  
• 4-ohm load at 1% THD: 640W
• 4-ohm load at 10% THD: 800W

General
The Conrad-Johnson Premier 350 is a high-power solid-state design with wide bandwidth and low output impedance typical of solid-state power amplifiers. It has a complementary MOSFET first stage that provides all the voltage gain of the circuit. The output stage is a complementary bi-polar compound gain of one circuit with MOSFET drivers. No overall signal feedback is used, although DC feedback is employed to help keep the output-offset DC voltage low.
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 (not shown as it won’t show up in the chart) in the audio range is of the order of +/- 0.1dB.
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.
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 admirably low in this design.
Damping factor vs. frequency is shown in Chart 4 and is reasonably 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 typical of many power amplifiers measured. The principal signal harmonics are of odd order with some low-level higher-order components.

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