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Pioneer SX-450

FM/MW Stereo Receiver (1976-79)

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Pioneer SX-450


The Pioneer SX-450 is a 15 watt FM/MW stereo receiver featuring FM muting, tape monitor switch and provision for 2 pairs of speakers.

The unit employs a direct-coupled OCL circuit in the power amplifier with a first-stage differential amplifier.

High FM sensitivity is ensured by a low noise FET in the front end with a frequency linear 3-gang variable capacitor.


Tuning range: FM, MW

Power output: 15 watts per channel into 8Ω (stereo)

Frequency response: 20Hz to 60kHz

Total harmonic distortion: 0.5%

Damping factor: 25

Input sensitivity: 7.5mV (mic), 2.5mV (MM), 150mV (line)

Signal to noise ratio: 70dB (MM), 90dB (line)

Output: 150mV (line), 30mV (DIN)

Speaker load impedance: 4Ω (minimum)

Semiconductors: 1 x FET, 3 x IC, 28 x transistors, 15 x diodes

Dimensions: 448 x 141 x 307mm

Weight: 8.6kg

Accessories: FM T-type antenna

Year: 1976


instruction/owners manual   English -

schematics   English -

service manual   English - Digger747

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Reviewed Mar 28th, 2016 by JATL

I had the same problem as w3flh. I replaced the filter captor at $2 and that solved the problem. I paid $15 for the unit. It sounds great in my man cave.

Reviewed Jan 07th, 2015 by w3flh

Just picked up this SX-450 to help round out a c.1978 all-Pioneer hi-fi set up {SX-450 receiver, PL-518 turntable, HPM-40 speakers, SE-405 headphones}. It's in very good shape, with every function and bulb operational, no scratchy pots, just the fluky start-up (static-y for 5 to 10 seconds before settling down).
Anyway, what a great sounding receiver! Solid power, providing rich musicality, with plenty of bass without being boomy, good extension on the highs, and nice clean playback throughout the spectrum. Don't worry about it only pushing 15W - this is true RMS wattage, conservatively rated, with plenty of headroom. A fine vintage receiver with minimal bells and whistles, a real workhorse.

Reviewed Jan 03rd, 2015 by mrmisi69

This product is the smallest one from the 1976 product range, and starts it from the bottom. These days only the bed time stories tells about such a built quality, performance that Pioneer offered even from the entry products. It is not an ultimate solution having non-plus ultra Hi-Fi product, however it does its job as a bookshelf receiver. The design still fits to today's living room. I bought it in very bad condition on second hand portal. After the usual re-newal steps (caps, aged resistors, transistors replacements, null-point setting etc..) the sound characteristic got improved big time. Only the beamed noise came from the transformator via high sensitivity parts of the amplifier caused low frequency noise. This noise was disturbing only by using headphone in silent enviroment, but I was curious enough to find its source. I realized that my receiver is assembled with a non shielded transformator, however it is an original part placed at the time of the production. By chosing the easiest solution, the transformator was turned clockwise a third, and suddenly the low freq noise dissapeared.
If you find this product in good shape, and ready for re-newal, definitely worth to deal with. I am sure this receiver will satisfy also someone else another four decads later.



re: SX-450

Thanks for manuals Digger747! My Pioneer sx-450 working fine now and i am going to keep it that way!

sx450 manual

Thank you for the manual. We are still using this receiver. I was considering replacing it but after reading the reviews I think I will keep it. The only problem is a broken volume knob!

Bought one for 15$. it is

Bought one for 15$.

it is nice to have the schematic ready in case something is wrong.


Pioneer SX-450 Receiver

The SX-450 was my first stereo,bought new in 1978,this is a cool little receiver.Had it hooked up to Zenith Allegro speakers and a B&O 2404 turntable.Have good memories of listening to Classic rock by the light of tuning scale.

Missing Pages?

My tuning string is broken. Your service manual includes directions to change the string, but is missing the pages (namely 14 and 15) that tell you how to safely remove the front panel of the receiver. If you don't remove the front panel, you can't change the string. Could you please help?


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