Faulty Electrics

Entirely normal. Most likely poor quality speakers.

This is due to your amplifier not having a capacitor blocking high frequency noise from other noisy appliuances connected to the same ring main.

There is no easy answer to this it can often happen with fridges also.

The best place to start is with your hifi.

Regards

Jim

That's strange, that a spike is getting through your UPS to the PC. Maybe a cheap UPS.

You do have a UPS (or even a mains filter) on the mains to your PC, don't you?

Actually, I think I already know the answer to that one, hehe!

Please add the following costs:- New PC = £ Several hours of your time = £ Loss of all that data you meant to back up but didn't = £

Now compare to :- New UPS cost = £60 to £100

Never ceases to amaze me that people don't use them.

Still, I have my hat, some mayo and a little salt ready and waiting to be eaten if the OP tells me that the PC (and speakers) are fed from a UPS.

Rob

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???

How is starting with the hifi going to help his clicking PC speakers?

In article , Pinot Grigio writes

Don't worry about it. PC speakers are of such piss poor quality they respond to anything like the slightest amount of RF energy. Trust me I'm a radio comms engineer:))

In message , Pinot Grigio writes

It may be the switch contacts are "dirty"

It also depends on at which point in the mains cycle you are switching

you might have inadequate rf filtering somewhere

Personally, I'd learn to live with it

Where the hell did a UPS come into it?

Cheap speakers, poor filtering, bad cable management.

nuff said

I missread the PC bit thought it was a hifi problem. As others have said it is high frequency "noise" causing the problem could try a plug in mains filter although.......maybe not worth the cash..

In message , tony sayer writes

Shock horror

Are the speakers driven off a separate amplifier fed from the mains?

What about a new light switch? carbon build up on contacts could be making problem worse. At a guess.

Many people who do use them never bother to test whether they will actually work when the mains fails.

Colin Bignell

If he turns it up enough, it will drown out the clicking.

Dave

Thats the time to worry, when ' experts' tell you not to worry .

Dave

I would have thought that the 'problem' is an amplifier one rather than speakers.

Even if he *did* have a UPS, there is no need to run speakers from it. As a general rule, you want to put the minimum of equipment on a UPS to maximise the run time when on batteries. Also, many UPSs don't filter the mains much, JUST provide backup power when the mains goes out. You have to get a decent UPS for this feature.

Also, UPSs are NOT a replacement for backups. Even with a top-of-the-range UPS your hard drive can still fail and lose all your data.

Alan.

True. Talking about "speakers" is misleading, because the problem is definitely not in the loudspeakers themselves, but most probably in the amplifiers (a stereo pair) that drive them, and/or their power supply.

However, before running away down that path, we need to take a step back, and ask the OP:

• Does any other audio device in the house (TV, mains-powered radio, hi-fi) show the same problem when you switch things on and off? Do the lights flicker?

If not, it's highly unlikely to be a major fault in your mains wiring.

Small disturbances on the mains are normal, whenever you switch anything on and off. What seems to be abnormal is that your amp/speakers are very sensitive to them.

Assuming the answer to the first set of questions was No, then try to narrow it down further.

• Borrow a completely different set of speaker/amps and power supply from another PC. Is the problem still there, or is it specific to your set?
• Aside from the specific problem you reported, is the audio background dead quiet, hum-free and undistorted? Or is the sensitivity to mains switching part of a wider problem?

There are two connections to the speaker/amps system: the mains power supply and the audio input from the PC. The electrical noise could be getting in either way, so:

• Unplug the audio input lead from the PC. If the problem is still there, the interference is coming in through the power supply.
• If the problem goes away when you unplug the audio lead, it could be either at the PC end, in the lead or its connectors, or the amplifier end (though I'd bet on the last two).

Given the answers to these questions, several people here might be able to help you further.

On Fri, 27 Aug 2004 08:25:54 GMT, "Alan" wrote: [snip]

I agree Alan. No need at all to run speakers through the UPS although, unless they are meaty speakers, their current drain would be minimal.

A UPS that doesn't filter the mains is not much use as to my mind any good quality unit will do this. I also agree that a UPS is not a replacement for a backup. But, many people do not backup as often as they ought and I was envising the (increasingly common) problem of mains spikes. When I worked in IT support, I was amazed by the number of times a PC/server went belly up and on opening the case, literally half of the components had blown off the motherboard and other cards. Needless to say the hard drive was toasted and much of these cases could have been avoided by the mains being filtered for spikes.

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On Fri, 27 Aug 2004 08:25:54 GMT, "Alan" wrote: [snip]

I agree Alan. No need at all to run speakers through the UPS although, unless they are meaty speakers, their current drain would be minimal.

A UPS that doesn't filter the mains is not much use as to my mind any good quality unit will do this. I also agree that a UPS is not a replacement for a backup. But, many people do not backup as often as they ought and I was envising the (increasingly common) problem of mains spikes. When I worked in IT support, I was amazed by the number of times a PC/server went belly up and on opening the case, literally half of the components had blown off the motherboard and other cards. Needless to say the hard drive was toasted and much of these cases could have been avoided by the mains being filtered for spikes.

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