Sony STR-242L

The STR-242L is a vintage stereo amplifier with a built in AM/FM receiver manufactured by the Sony Corporation in Japan.

This is a high quality vintage amplifier built around an all-metal chassis. This model was very similar to the build quality of the ST-242L, which was just a tuner without the amplifier section.

The integrated AM/FM radio circuit in this unit is a fully realised heterodyne receiver based around the LA range of Sanyo chipset. This chipset was one of the best found in many high-end audio equipment, including walkmans. It later became the de facto standard for high quality radio including walkmans. It consists of a monolithic IF system, electronic tuner, and a Phase Lock Loop (PLL) multiplexer.

The amplifier section uses the famous Sanyo STK465 stereo amplifier IC utilising the high quality IMST Hybrid IC Design. Please follow the link for more information about this chip. This chip provides superb sound quality, with a highly defined bass and tone. Unfortunately, this IC is no longer in production, and a genuine one is difficult to find these days.

I just love these old vintage Sony amplifiers. This is from back in the old days in the 80s when Akio Morita was driving the vision for Sony products. These amplifiers were meant to last almost forever, and consequently, they were robustly built. Every aspect of this amplifier has special detail and attention placed into it. From the outside controls, to the sound quality, to the electronics, this is why this old amplifier is still worth something. It seems to me that Akio Morita was my kind of engineer who placed great attention to detail.

It has these wonderful finely crafted selector switches. There are options to select a either a phono or tape input. There are five presets for FM stations, and a manual tuning option.

The amplifier specialists in the UK :-) will be pleased to learn that all the knobs are made of metal. They appear to be turned aluminium, with plastic inserts. The master volume control has a stepped feel when you turn it.

It has this lovely colourful signal strength meter, with bright LEDs from the 80s.

Almost all amplifiers based on the STK465 chip provide a warm creamy bass, and a well-defined treble. The secret is in the way Sanyo created this chip using IMST fabrication processes.

The power button is made of metal and has a very soft feel when you press it. The spring inside it has just enough tension to push it out when in the OFF position. The gap between the button and the surrounding front panel is very small, and the slightest amount of dust can make it jam. I used some android aftershave (WD40) to clean it, and it works perfectly now.

Buying on eBay

These amplifiers were mass-produced at one time, and there should still be plenty around. Unfortunately, due to the wonderful sound quality produced by the Sanyo chip, many people overload it by attaching too many speakers, and having it at full volume. A faulty burnt-out one that is in an excellent condition could still fetch around £10 or more depending upon its condition. Also, do not forget that this is a heavy amplifier, and the buyer has to pay for the postage. In addition, a genuine replacement STK465 chip will be expensive to procure.

I paid a fiver for this because it was in an awful state. Although the seller had managed to take a great deceptive photograph, the top cover was full of rust. Honestly, you do not want to see the picture of this, as it will scare you; however, I lovingly restored it back to its working glory. In fact, since I, the legendary Peter Vis :-) put my hands on it, it is now worth its weight in gold. I must have the Midas touch.

I took the top and bottom covers to my friend Darren who has a car paint shop garage and he sorted those out for me with a professional paint job. I also carried out some extensive modifications and improvements to the circuit, and now it works better than ever. Wonderful clear bass and treble, warm creamy sound, and just beautiful to look at and that is just the amplifier. :-)

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