I took a look at a cheap phono amplifier – Is it any good?

Vinyl sales are up and people are getting turntables only to discover their amplifier doesn’t have a turntable input.

Testing a cheap phono amplifier to see if it's any good

When CD players became a thing many amplifier manufacturers followed the trend and stopped fitting turntable inputs to their amplifiers as they weren’t needed.

It probably made sense at the time as the turntable input required additional electronics and thus cost.

Now that vinyl is back, rather than replacing your amplifier with one that has a turntable or Phono input you can buy a device called a phono amplifier that sits between the turntable and one of the existing inputs on the amplifier such as the Aux input.

Being HiFi, there are cheap phono amplifiers and high end ones as some hifi enthusiasts will buy an expensive one to bypass any built in one as it’s possibly better. They do the same thing with CD players and buy a DAC.

So, I brought a dead cheap phono amp (£10) from Aliexpress to see how it performed. I also wanted to see which components they’d used on the circuit board.

If you’re searching for a phono amp you will probably come across these (or something very similar looking) as they’re on eBay and Amazon, for slightly more.

I’ve put a video of my findings on my YouTube channel but in a nutshell it’s a waste of money.

The output has hum / buzz on it and it hasn’t got enough gain so with the couple of amplifiers I tested it with I had to crank the volume up way past the mid point to get any decent sound level.

Due to the lack of gain, when you crank the volume of the main amplifier up it brings the background noise level of the phono amp up, which is the buzz.

If the audio that came out of the phono amp was louder it would be way above the background noise so it wouldn’t be as noticeable. It would be easy to increase the gain by changing some resistors, but that’s not the point of this test.

The difference in volume between different sources is a pain as ideally you want all the sources such as turntables,  radio tuners, CD players etc to all be at about the same volume level so when you switch between them the volume is the same.

Connecting the earth point on the preamp to mains earth made no difference. Earthing the amplifier didn’t make any difference to the buzz either.

It’s really easy to get hum on a phono amplifier as it’s all around us in the form of 50Hz (60Hz in the USA) radiation from the mains electricity supply. Phono amps have to amplify a very low level signal so are susceptible picking up unwanted electrical noise.

You can also get earth loops which is why the phono amp and main amplifiers usually have a separate earth point. Sometimes you have to connect it to earth, other times you don’t.

I think the mains adapter is the primary cause of the buzz. Just having it connected to the CD input on my amp but with the amp switched to another source made the thing buzz.

I wouldn’t trust the adapter to be safe as it’s so light it will have next to nothing inside it. I assume the power supply is a switch mode design and probably gives out all sorts of electrical interference due to its price.

Remember, the amp and PSU together are sub ten quid shipped to the UK, so you get what you pay for. That includes electrical safety as well as audio quality.

As a comparison, the following link shows you an old £1000+ phono amplifier I once had in for repair.

A Tom Evans The Groove phono amplifier repair

The The vinyl revival