http://www.stereophile.com/conte ... lifier-measurements

从评测来讲，动态优秀、但失真一般！

Sidebar 1: Specifications
Description: Solid-state monoblock power amplifier. Inputs: unbalanced voltage-mode (RCA), unbalanced Zeel (BNC), balanced (XLR). Output power: 450W (26.5dBW) (850W peak) into 8 ohms, 800W (26dBW) (1700W peak) into 4 ohms, 1000W (24dBW) (1800W peak) into 2 ohms (software limited). Voltage gain (user selectable): 26 or 32dB into 8 ohms. Input impedance: >30k ohms, 5Hz–200kHz (RCA); 50 ohms, ±1 ohm (Zeel); 10k ohms per phase (XLR). Output impedance: <0.28 ohm, 20Hz–20kHz (into 8 ohms). Frequency response: 0.7Hz–700kHz, +0/–3dB; 20Hz–20kHz, +0/–0.2dB. THD: <1%, 7Hz–77kHz. Signal/noise: >115dB, A-weighted, ref. nominal power.
Dimensions: 18" (460mm) H by 11" (277mm) W by 20" (511mm) D. Weight: 154 lbs (70kg).
Serial number of units reviewed: TZ-UA1458.538L/R.
Price: 135,000 Swiss Francs/pair ($144,500/pair at time of going to press). Approximate number of dealers: 9.

The unbalanced input impedance, specified as being >30k ohms, was a usefully high 46k ohms at low and middle frequencies, dropping inconsequentially to 37k ohms at the top of the audioband. The balanced input impedance was 20k ohms at all frequencies, as specified. The output impedance was high for a solid-state design, at 0.3 ohm (including 6' of speaker cable) at all frequencies. Consequently, there was a slight, ±0.25dB variation in frequency response with our standard simulated loudspeaker (fig.1, gray trace), due to the Ohm's Law interaction between this impedance and that of the load. The NHB-458's small-signal frequency was otherwise flat within the audioband with all impedances above 2 ohms; the bandwidth into 8 ohms was wide, the response being down by <1dB at 200kHz (fig.1, blue trace). As a result, the amplifier's reproduction of a 10kHz squarewave into 8 ohms featured very short risetimes (fig.2), with no trace of overshoot or ringing. Good stuff!
包含6尺喇叭线在内输出阻抗0.3，对于晶体管机来讲有点高。（一般通用的方法是接模拟喇叭假负载!阻抗是恒定的。一般功放实际接喇叭后、测试指标还要差好多！）

http://www.soundstagemagazine.com/measurements/tenoraudio_75wi/这台功放阻尼只有10左右，但是国外人用它推落魂的老旗舰、功率也不大（应该是不带变压器的真空管机，当时的价格也两万美金了）

aa amp 2 ac不差的

换个话题吧!

你到底需要多少钱？

aa amp 2 ac不差的
guhelim 发表于 2012-11-7 20:05

没说它差，只是不合适推有些喇叭而已。再说也不是好功放通吃所有品牌的喇叭。

这台功放阻尼系数1500以上（10赫兹之1千赫兹之间），这台功放控制力非常好，但就是没推好过丹拿！这个厂的 ...
musicmad 发表于 2012-11-7 18:18

应该是控制力太大，将喇叭控制的太死。

功放如果对于喇叭的阻抗变化的跟随能力强的话，对喇叭的推控才自如的多。这比一味地增加功率更重要。
musicmad 发表于 2012-11-7 17:05

这话有道理。但瓦数是个大前提，瓦数和音箱的的灵敏度和输出声压的关系必须先满足才可谈其它。

TGLEE兄，高阻尼系数是不是都要靠深度负反馈来实现？柏林的后级阻尼系数比AA的更高。

上面的英文翻译过来，大致的意思是：在音响设计界有个心照不宣的秘密，就是最好的功放是低功率的，有人甚至 ...
甲米 发表于 2012-11-5 15:52

一般对于晶体管机，如果你需要10瓦功率能达到你的声压要求的话，就选100瓦的功放即可。主要是对晶体管机来讲、得有足够的储备功率。

TGLEE兄，高阻尼系数是不是都要靠深度负反馈来实现？柏林的后级阻尼系数比AA的更高。
上海粉丝 发表于 2012-11-8 23:28

阻尼系数与功放输出内阻成反比. 负反馈可以降低输出内阻, 但随之带来的是相移及瞬态失真.