If you’re anything like me, you can’t resist picking up a bargain – especially when it’s a cheap piece of electronics that someone in their, er, wisdom has decided no longer has the right fashion look. Take audio hifi amplifiers, for example. Visit (in declining order of salubriousness) secondhand stores, garage sales, roadside rubbish collections and the tip and you’ll find a host of amplifiers that are available at ridiculous cost (as in, ridiculously low . . .).

Consider, for example, the Rotel 712 integrated stereo amplifier shown on these pages. It cost me just $8.00. Yes, that’s right . . . eight bucks. What was wrong with it, you ask? Answer: nothing.

Fig.1: all the tests require a set-up like this. The PC's sound card output is connected to the amplifier's input, while the amplifier's output drives both the dummy load (the jug elements immersed in water) and the monitoring speaker (via a 150Ω resistor). The multimeter is used to measure the AC voltage at the amplifier's output.

Similar bargains can be had in lots of places. Recently, I bought a Rotel (yep, I like that brand) RX-203 stereo receiver for . . . wait for it . . . $3. So what was wrong with that one? Well, I haven’t tested it yet but I’ll wager that it also works fine.

Talking about testing, until recently I thought that any meaningful testing of an amplifier needed stuff like oscilloscopes, standalone frequency generators and specialised audio test gear that I didn’t even know about. But then, through the advice of three learned men, I saw the light – the amplifier "test light", so to speak. Those three wise men advised me that all I needed was a digital multimeter, my trusty PC, a few cheap resistors . . . and a jug element!

A jug element? It all sounded so crazy that it might just work.

But do the figures really matter? After all, the reason that you buy an audio amplifier is to listen to it. The answer is yes, especially if you’ve heard the distorted sound that some appear people to like.