The Pioneer SX-838, released in 1974, features a combination of excellent sound quality, power, and classic design. Its retail price was $499.95. It delivers 50 watts per channel into 8 ohms with 0.3% total harmonic distortion. Today the x3x line from Pioneer is highly desired for both its performance and its looks.
Controls
The controls on the SX-838 are well laid out. Notice the horizontal row of black push buttons just under the dial face. The SX-838 was produced during the transition into the silver faced era. The black push buttons essentially represent the older design aesthetic and the brushed aluminum knobs and switches the new aesthetic. Later models from Pioneer used almost all brushed aluminum controls.
The speaker selector controls, filters, input source controls, mono and loudness controls are all located on this row of black push buttons. It has six program sources (AM, FM, Phono 1, Phono 2, Mic and Aux).
Pioneer added an interesting feature to the SX-838 called the Recording Selector that permits FM recording while listening to records and vice versa.
The dial face on the Pioneer SX-838 is beautiful. The blue dial scale really contrasts with the red dial pointer. The tip of the pointer glows brighter when a strong signal is achieved.
FM Tuner
The Pioneer SX-838 features PLL FM MPX, a precision equalizer, switched-turnover tone controls and a direct-coupled OCL power amp. Its other features are:
The FM tuner of the SX-838 has a number of features to enhance its performance. Its front end is equipped with a frequency-linear 4-gang variable capacitor and two MOS FETs, which contribute to high sensitivity and exceptional rejection characteristics.
The FM intermediate frequency (IF) section is designed with a 6-stage limiter and phase-linear ceramic filters to improve signal processing.
The FM MPX demodulator incorporates a Phase Lock Loop (PLL) circuit with an IC to ensure precise signal demodulation.
As a result, the SX-838 exhibits remarkable capabilities, such as an FM sensitivity of 1.8uV, FM selectivity exceeding 80dB, a capture ratio of 1.0dB (according to IHF standards), and a stereo separation of more than 30dB within the frequency range of 50 to 10,000Hz.
The SX-838 produces 50W + 50W of continuous RMS power (both channels driven at 8 ohms) with total harmonic distortion of less than 0.3%. This figure is measured and guaranteed over the entire spectrum from 20 to 20,000Hz. That’s why when most of the x3x receivers are bench tested they produce significantly more wattage than rated.
Other receivers in the Pioneer’s lineup at the time included the SX-434, SX-535, SX-636, SX-737, SX-939 and the top-of-the-line SX-1010 which many feel may be Pioneer’s best built receiver ever.
Here are the specs for the SX-838:
The ad below shows the Pioneer lineup during the latter stages of the product cycle when discounting was starting to occur.
The Phono equalizer in the SX-838 provides accurate reproduction of all the sounds in any record groove by assuring no more than ± 0.3dB deviation from the RIAA curve.
There are some common issues with the SX-838. The black push button switches can get dirty and stick in either the on or off position. This can be remedied by cleaning them but may require removal of the faceplate. Some thorough cleaning with DeOxit should do the trick.
If you’re looking to upgrade your SX-838 there are a number of kits and other parts available on eBay HERE.
What do owners say about the Pioneer SX-838:
It will drive almost any speaker on market at that time (Bose 901 being the notable exception). It’s real worth is in it’s warmth, detail, low distortion, low noise, large dynamic range, large selection of inputs and triple pair of speaker outputs.
My favorite series of Pioneer receivers is the x3x series. A lot of it is looks (even the 434 is a looker), but all of that series was underspec’ed for power.
It’s a very well-made, classically-styled receiver with a very pleasant sound.
The sound is simply wonderful. Very rich, deep bass and crisp, clear highs. CD player through AUX is excellent.
Overall, the Pioneer SX-838 is an excellent receiver. It has the cool early Pioneer styling, underrated power, and plenty of features. Pioneer sold a ton of them so they are fairly common, which means prices aren’t as crazy as some other brands and models, and parts are pretty easy to come by.
