How do I make sure that my AV receiver doesn't blow?

Question

My AV receiver has just overheated. I'm thinking about getting a new one but was just wondering what I need to look for in the speakers that I match up with it (ie. impedance and power). Do I need specific speakers depending on what receiver I'm getting? What causes an AV receiver to overheat and blow?

I really want to make sure I get it right this time. Don't have much budget to continue buying receivers if they keep blowing up on me!!

Answer 1

Receivers can overheat from inadequate cooling, which could include buildup of dust.  But they could "blow" from faults in the electronics (shorts) or working into an innapproriate load (e.g. driving 4 ohm speakers with an amp designed for 8 ohms) over a long period of time or at high levels, etc.

Most speakers are nominally 4, 6 or 8 ohms (rarely 16 ohms)  -- although actual impedence varies with frequency so this is an average --  and all receivers will handle an 8 ohm speaker. Poorly designed ones might have problems with 6 ohms, but a 4 ohm speaker requires a receiver that is specifically rated for 4 ohm loads.

Check your current speakers and see what they are, and buy a receiver/amplifier accordingly. Sometimes there is a switch on the back of the receiver that should be set to correspond to the speaker impedence.

Just don't buy an overpowered amp (one rated to deliver more power than the speakers can handle) or you could blow up the speakers this time!

Other than that receivers and speakers are fairly well standardized and you should not have any difficulty finding a new receiver. As with most equipment, you are likely to get better performance and longivity from quality equipment .. so look for name brands (e.g. Onkyo, Pioneer, Yamaha, Harman Kardon, Sony, ...).

Hope this helps.

Answer 2

First - check that you did not over-heat because the speaker wires have strands of copper sticking out causing a short.

Second - buy a well-known receiver with a protection circuit built in. This allows the receiver to go into "PROTECT" mode instead of destroying itself. Stick with Yamaha, Dennon, Sony ES, Pioneer Elite models.

Third - buy banana plugs from Radio Shack or PartsExpress and learn how to do a neat wire job to prevent shorts.

POWER AND SPEAKERS

There are lots of issues here, but I will try to summarize.

You want to find monitor-style speakers that are 8 ohm nominal impedance.

You want a self-powered subwoofer.

You want to tell your new receiver that all your speakers are SMALL so it will send power-hungry low frequency duties to the self powered sub.

You want the heaviest receiver possible. If you find 2 models that produce 80 wpc, but one is ten pounds heavier, buy the heavier unit. It has a larger transformer and will tend to run cooler.

You want to put the receiver on the LOWEST shelf in your rack.  The heat from the vents need to 'see' lots of space above so it flows away.

Answer 3

There are many specs to look for in a good piece of equipment. Too many in fact to go into detail, it would be a books worth....

In fact some one has written a book about this very subject.

Answer 4

Any electronic subjected to inadequate ventilation with get hot and bothered. The user manual will probably give an ideal installation. If however you want to tuck it away into an AV console installation you'll need to add a fan or two to get enough airflow.