Home theatre makeover, start with an amplifier

Today's receivers may be jam-packed with the latest technology, but they lack the muscle of high-end power amplifiers. If your home theatre is above average in size, say 300 or more square feet, and you like to listen nice and loud, there's a good chance your receiver's power amp is the weak link in your system. There are some impressive amps out there across a wide range of prices - an excellent home cinema experience doesn't have to cost a fortune.

When Choosing An Amplifier

We focus our efforts and budget only on specs that make a real difference to the sound you hear. When choosing an amplifier, look out for these specifications:

Power output:

Power output is roughly equivalent to how loud you can pump out music. The bigger the speakers or room, generally the more power you want (much to your neighbours and housemates dismay!) However, you probably don’t need as much power as you’d expect. Generally, 10W is pretty loud for average listening and 100W is enough to blow the roof off most parties! Hint: Be sure to look at speaker sensitivity, since this has a big effect.


Total Harmonic Distortion + Noise (THD + N) is a measure of just how much effect the amplifier has on the sound output. More distortion generally means more colouration to the sound. The lower this figure, the closer the output of the amplifier will sound to the original recording. Of course, speakers will have the biggest effect on sound, so choose some that are well matched to your listening preference. Hint: Lower numbers are better.

SNR (Signal to Noise Ratio):

If you stand in a quiet room, in the countryside, away from the hustle and bustle, you might notice noises you’ve never noticed before. The humming of a radiator or cars travelling down a nearby road for example. None of this is apparent when the kids are home with the TV blasting away, but that background noise is still there. An amplifier is the same, there is always a very small amount of noise from the electrons whizzing around inside. The goal is to make this background noise imperceptible, this means you hear more of the music and less of the noise. The measure of this is the signal to noise ratio. Hint: Bigger numbers are better!


Left is Left, Right is Right and Crosstalk is a measure of how much undesirable left signal is mixed with right output. Amplifiers all being one box are doing their best to be separate boxes one per channel, splitting apart the signals to ensure when it reaches the speakers, you can tell that the singer is standing slightly to the left of the stage and the violins towards the right. The more crosstalk there is, the harder it is to pick out the positions of the instruments as stereo separation is affected. Hint: With crosstalk, the larger the number following the minus sign (i.e. -60dB is not as good as -100dB) the greater the stereo separation.


Can you connect up everything you want to? You’ll want to make sure you have enough inputs for everything you’re plugging in! Remember the different type of connections, like 3.5mm for iPods, Phono for turntables and USB for laptops and home theatre PC’s. They all have advantages and when there are a few options, choose the one which provides the best sound quality. Hint: We separate out phono stages in our Azur products, and guarantee best performance as the signals from a turntable are very small and can be easily interfered with.