Amplifiers

AV or Stereo

Yamaha amplifierThe first choice to make when buying an amplifier is whether you want an AV or stereo amp. A stereo amplifier is the simplest way to improve your speakers' sound quality at the lowest cost. It has a 2-channel stereo audio output signal sending the amplified sound down the two channels – left and right. If you want an amplifier that can amplify across more than two channels for surround sound then you should look at an AV amplifier.

The multi-channel AV amp can handle audio and video input. The difference between the two isn't the sound quality they offer. A stereo amplifier is solely designed for amplifying music which means you get a much better sound quality for a with stereo amp than a similar priced AV amp. You can really enjoy improved sound quality with a stereo amplifier and TV and DVD audio is transmitted in stereo. Although if you have a sub-woofer, most stereo amplifiers don't have an output to accommodate it, so you will have to look into getting a multi-channel AV amp. If you have a home cinema system, then this is the amp for you as it can power your system providing surround sound.

Whether the devices in your cinema system output stereo, analog or HDMI, the AV amplifier can connect them all. AV amps can play from 2.1 to 5.1 surround sound, but some higher end models can handle 7.1 or 7.2 surround sound that can accommodate more speakers and subwoofers.

More choices

Vision stereo amplifierThere is a huge spectrum of choices to make when deciding which amplifier best suits you. In terms of sound quality, there are two types of amps: integrated and pre/power amp. The pre/power amp normally produces the best sound performance by keeping each element of the amp separate but the extra hardware means extra price.

The next important choice to make is to find out which amplifier technology best suits the sound you are looking for. The two technologies – transistors and valve – both possess different qualities. If you are looking for an amplifier to solely to crank up your volume, then the technical advantages of a transistor amp will best suit. But, if you're after a richer sound, then a valve amp provides a better sound quality than the transistor.

Amplifiers also come with a different number of inputs and outputs. An amp with a greater number of output ports will allow you to connect extra speakers and sub-woofers without trouble. Also, if you are looking to connect up Blu-ray player, game console and satellite TV, you will have to make sure that the amp has adequate inputs.

The cheapest amplifiers start at around £100 and there is an extensive range of stereo amplifiers starting at this price. The lower end AV amplifiers start at a few quid more and can catapult well over £1,000 for the highest specification models. AV amplifiers with the same sound quality capabilities of a stereo amplifier cost around three to four times more.

Power

When choosing an amp, the amplifier output power is an important factor that you need to consider when deciding how much power you require. It's also worth considering that a higher watts rating doesn't necessarily mean a better sound quality. Which power level you need is dependent on the speakers you already have. If you can match up the power needs of your speakers with the output power of the amplifier, then you will get the best results. If you have a speaker with a lower sensitivity of 88dB to 93dB, then you need to be looking for an amp with more power. If the sensitivity efficiency is over 93dB, the speaker will require less amp power to play just as loud. So if you have a high sensitivity speaker, a 20 watt amp could do the job whereas it would take a significantly bigger amp to drive a lower sensitivity speaker.

If you don't buy an amplifier that doesn't exactly fit your speakers, it isn't a big deal. But in this scenario, it is better to get a bigger wattage per channel. If the speakers are a good size for your room, you will not need to use the full volume of the amplifier compared to not having enough wattage with the highest volume level not being loud enough. The most important thing is that you have enough power to fill the room and even the length of your room and height of you ceiling is worth taking into consideration.

Receivers

Onkyo receiverReceivers are another component of any hi-fi system or home cinema package. They sometimes contain an AM/FM, DAB or satellite radio in them. Most importantly, they are the hub for all of your stereo and AV inputs: TV, DVD or Blu-ray player, turntable, CD player or even a cassette player if you still have one. The receiver allows you to choose which device you're going to route a signal to. There is a difference between a simplified stereo receiver and one for audio-visual use: the addition of a video signal relay. It's simple, really. Are you looking for create a stereo system for music only or are you looking to kit out your home cinema with lots of goodies and components?

Extra specifications

Once you have deliberated on the key decisions of which amp is best for you then you can start to consider which model offers the sound quality you want. The transparency of sound is the most noticeable, single difference in sound quality between amplifiers. Amps that tend to focus on and accentuate detail will sacrifice this for the consistency of the overall sound and which is best is down to your personal preference.

Amplifiers that have strong stereo imagining will be able to provide a full, spacey sound that fills the room. Amps that are dynamically strong have more oomph and amps with good timing provide a sharp sound quality.

An AV amplifier can drastically tidy up the back of your home cinema system by reducing the amount of cables needed to connect everything. If this is something that you are interested in then look into the upconvert and upscale ability of the amp. If the amp can convert the inputted signals and has the ability to convert low resolution content into higher resolution then this will negate the need for so many cables.

AV amplifiers often include on screen displays as well which are handy for viewing set up information and amp statuses like volume can be displayed.