LP-838 Amplifier

The LP-838 is a 2.1-channel stereo power amplifier manufactured in China. It often comes in different names such as Lepy, Lvpin, Lepai, and Elegant. The chipset consists of TDA7057 stereo power amplifier IC, TA8201 power amp IC for the sub-woofer, and JRC4558 operational amplifier IC. This unit requires an external 12 V power supply to operate.

Review

This is an extremely low-cost budget-end amplifier with a good chipset by Toshiba, Philips, and JRC, and consequently is sounds fairly decent if you use it with a good quality power supply and speakers. Ideally you should use a power supply with a conventional transformer instead of the cheap switched-mode adapters which can be noisy and affect the power factor.

It has some advantages such as good bass and treble response, subwoofer output, and small size. It costs approximately the same as two cups of coffee in the UK and they also manage to post it all the way from China. In the end, you get what you pay for, and obviously it is not for audiophile application, but it has a cheap and cheerful design that could suite audio enthusiasts, and those who do not listen to loud music. If you were a hobbyist thinking of building a small power amplifier, then it would probably cost more to buy the components separately, hence this can be a bargain. I liked the brush metal case, and when I saw it I thought it would be ideal for one of my turntable preamplifier projects, because stylish project cases are difficult to find. Unfortunately, this amplifier, which I bought pre-used, turned out to be working, so I shall just have to keep on looking for something else.

Price/eBay

I bought this pre-used amplifier in the spares and repairs section and the seller mentioned that only one channel was working. However upon testing, it turned out that the potentiometer tracks simply needed cleaning and then I was able to hear all the channels very well. I only paid a couple of pounds so it turned out to be a great bargain, and it gave me a chance to see the electronic design. The price of a new one can vary greatly online, however around the ten pounds mark seems fair considering the build quality and design.

In the following pages of this multi-page article you can see the electronic engineering, chipset and PCB.

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