Effect of unstable electricity on Audio

[Viagara]

This subject has been discussed briefly in the past, but with the current Eskom situation it could be more relevant now.

With the electricy supply not being very stable or consistent, do you think it could have an effect on the sound quality of equipment?

I know this cannot be considered to be audio equipment, but since the problems started with Eskom my wife's radio alarm looses time and someone told me that it has to do with the electricy supply not being stable at 50hz. Any truth in that?

And what effect will that have on audio equipment?

[Shonver]

I know this cannot be considered to be audio equipment, but since the problems started with Eskom my wife's radio alarm looses time and someone told me that it has to do with the electricy supply not being stable at 50hz. Any truth in that?

Some older clocks use the mains 50Hz signal as a reference clock. If your CD player does, too, you're in trouble 

[Viagara]

Some older clocks use the mains 50Hz signal as a reference clock. If your CD player does, too, you're in trouble 

Makes sense as this is a very old clock.

I am however still curious to know what effect fluctuations could have on audio equipment, say the voltage dropping to 215 volts or amperage dropping. I am sure the standard answer will be that if your transformer is worth its windings, there should not be any detrimental effect, but how sure can we be about that?

[Hennie]

I think fluctuations in the 50Hz frequency won't have an effect because the drift would still be too small.

However, undervoltage may be a bigger problem. I already lost 2 PC power supplies and I suspect it is due to undervoltage. Before load shedding became common, I regularly measured mains voltages as low as 195V.

Undervoltage may affect audio equipment, but it is difficult to generalize without looking at the specific circuit design.

[Byrd]

but it is difficult to generalize without looking at the specific circuit design.

In general however for an amplifier, the wattage it can deliver will be less than what it would have been at full voltage. It can also lead to instability

But as Hennie says - without looking at exactly how it was designed it is difficult to say. Most equipment with lower power requirement will be regulated, which means the power supply supplies a certain voltage and it is then regulated down to a lower voltage, so as long as the dip is not low enough to cause the power supply to dip in output below what the regulated voltage is then things should be fine.

[Hennie]

Yes sure Byrd, I overlooked the most obvious - power output of amps will be reduced - for a 195V mains voltage a 100W amp will become a 70W amp.....(square relationship between voltage and power output)

I started measuring mains voltages because the stove, the toaster and the kettle seemed slower, so I should have known that!

One TV power supply failure I had may also be related to undervoltage. I have not looked at that, but maybe switching power supplies have to work harder to bump up the undervoltage.

Since load shedding started, I have not measured ridiculously low mains voltages however.

[Viagara]

I started measuring mains voltages because the stove, the toaster and the kettle seemed slower, so I should have known that!

This I have noticed, particularly with the stove

[Dave F]

Does anyone know if this could affect plasma screens. I'm having a strange "green tinge" on anything shadowed or dark.

[chris]

MY Plasma and Lcd are rated 110v-240v so no problem there.

[joel]

Possibly has something to do with how much noise is being pumped down the power lines along with the AC.
I would try a line filter and see if this helps.

The Clearline models arent too expensive and you get free lightning damage insurance with them too.

[Soundworx]

Just another thought I had when reading reviews etc ... specially regarding canles and so forth ...

Some spend quite a lot of money on power supply cable  ... from the wall socket to the amp/powersupply.  Which helps bogger all if your home's wiring is crappy work.

[AV]

Your home wiring shouldn't be crappy work, fire the electrician

Read the NEW Cable arguments thread, there is something about power cables also.