这款 Pioneer SX-636 是 Pioneer 于 1974 年推出的中档产品，零售价为 350.00 美元。 它每通道仅产生 25 瓦到 8 欧姆，但正如 Pioneer 在其营销手册中所说：
“并非所有高保真情况都需要大功率设备。 如果您的听音室大小适中，并且您真正想要的是中等功率型号的更高效率和更复杂的多功能性，那么 Pioneer 的新型 SX-636 将是一个不错的选择。”
SX-636 在瓦数大战前几年问世，因此 25W每通道似乎并不不足。 而且它不适用于大多数聆听情况。 此外，接收器看起来不错，并且具有许多低端接收器所没有的功能。
前面板具有低音和高音控制、高滤波器、单声道和响度开关，以及用于 FM、AM、PHONO、MIC 和 AUX 的功能控制。 停电风格的 FM 线性刻度盘有两个调谐表、发光的节目指示灯和一个立体声耳机插孔。 控制开关是按钮，而不是您在许多后来的 Pioneers 模型中看到的切换样式。 发光的表盘指针也很漂亮。
规格：
调谐范围：FM、MW
功率输出：每通道 25 瓦到 8Ω（立体声）
频率响应：20Hz 至 30kHz
总谐波失真：0.5%
阻尼系数：35
输入灵敏度：7mV（麦克风）、2.5mV（MM）、150mV（DIN）、150mV（线路）
信噪比：65dB（麦克风）、70dB（MM）、90dB（线路）
输出：150mV（线路）、30mV（DIN）
扬声器负载阻抗：4Ω（最小值）
半导体：1 x FET、3 x IC、33 x 晶体管、17 x 二极管
尺寸：480 x 147 x 405mm
重量：11.2kg
年份：1974
橱柜是木纹乙烯基，看起来还不错。
Pioneer SX-636 有一个很好的调谐器部分和一个非常好的唱机部分。 FM 调谐器在前端采用低噪声 FET 和 3 路可变电容器。 通过精确的唱机均衡器实现高保真声音再现，使 RIAA 偏差保持在 +- 0.5dB 以内。
如上所述，直接耦合的 OCL 功率放大器在 20 赫兹至 20,000 赫兹的 8 欧姆下提供每通道 25 瓦的连续功率输出，总谐波失真不超过 0.5%。
SX-636 确实偶尔会出现一些晶体管坏的问题（尤其是功率放大器上的 2SC1451 晶体管），当然还有烧坏的灯。 它也没有保护继电器，而是依靠后面板上的两个保险丝。 但是，这些更多是为了保护扬声器而不是放大器本身。
1970 年代中期 Pioneers 音响的制造质量非常好。 后来的 SX-X50 系列可能是最好的，但 SX-X3X 系列紧随其后，并且没有太多难以找到的专有 IC。 如果您需要对其进行技术研究，它也很容易工作，可以为您省钱。
总的来说，Pioneer 的 SX-636 是一款出色的中档接收器。 如果您正在寻找带有良好唱机放大器来播放唱片的东西，或者想要在中小型房间里播放美妙的音乐，那么请务必查看 SX-636。
原文：https://classicreceivers.com/pioneer-sx-636
This Pioneer SX-636 was a mid-range offering from Pioneer in 1974 and retailed for $350.00. It only produces 25 watts per channel into 8 ohms but, as Pioneer stated in their marketing brochure:
“Not all high fidelity situations require high powered equipment. If your listening room is of average size, and what you really want is more efficiency and more sophisticated versatility in a medium-powered model, Pioneer’s new SX-636 will be a good choice.”
The SX-636 came out a few years before the wattage wars so 25 wpc didn’t seem inadequate. And it wasn’t for most listening situations. Besides, the receiver looks good and has a number of features that lower end receivers don’t have.
The front panel has bass and treble controls, high filter, mono and loudness switches, and a function control for FM, AM, PHONO, MIC and AUX. The blackout style, FM-linear dial scale has two tuning meters, illuminated program indicators, and a stereo headphone jack. The control switches are push button instead of the toggle style you see on many of the later model Pioneers. The illuminated dial pointer is a nice touch as well.
Specifications:
Tuning range: FM, MW
Power output: 25 watts per channel into 8Ω (stereo)
Frequency response: 20Hz to 30kHz
Total harmonic distortion: 0.5%
Damping factor: 35
Input sensitivity: 7mV (mic), 2.5mV (MM), 150mV (DIN), 150mV (line)
Signal to noise ratio: 65dB (mic), 70dB (MM), 90dB (line)
Output: 150mV (line), 30mV (DIN)
Speaker load impedance: 4Ω (minimum)
Semiconductors: 1 x FET, 3 x IC, 33 x transistors, 17 x diodes
Dimensions: 480 x 147 x 405mm
Weight: 11.2kg
Year: 1974
The cabinet is wood grain vinyl and doesn’t look too bad.
The Pioneer SX-636 has a good tuner section and a very good phono section. The FM tuner utilizes a low-noise FET and a 3-gang variable capacitor in the front end. High fidelity sound reproduction is achieved with a precise phono equalizer that keeps RIAA deviation within +- 0.5dB.
As mentioned above, the direct-coupled OCL power amplifier provides continuous power output of 25 watts per channel at 8 ohms from 20 Hertz to 20,000 Hertz with no more than 0.5% total harmonic distortion.
The SX-636 does have some occasional issues with bad transistors (especially the 2SC1451 transistors on the power amp) and, of course, burnt out lamps. It also does not have a protection relay, and instead, relies upon two fuses on the back panel. But, these are more for the protection of speakers rather than the amp itself.
The build quality of the mid 1970’s Pioneers stereos was very good. The later SX-X50 series was probably the best but the SX-X3X series is a close second and doesn’t have too many difficult to find proprietary IC’s. It is also very easy to work on which can save you money if you need to have a tech look at it.
Overall, Pioneer’s SX-636 is a great mid-range receiver. If you’re looking for something with a good phono amp to play records or have a small to medium sized room you want to fill with great sounding music then be sure to check out the SX-636.