UPS and iMac: Stepped or Pure Sine Wave?

[imanidiot]

I know that this subject has been discussed, but I was wondering whether there was any consensus here on whether or not Macs need a Pure Sine Wave UPS? I need to replace a 3+ year-old APC unit of the stepped-wave variety which has been fine. When I purchased it I was unaware of the whole Pure Sine Wave - Stepped (approximated) Sine Wave issue. Does it really matter? I've heard yes it does / no it doesn't in just about equal measure.

Sorry if this is stupidly redundant.

 

[fhall1]

If you're really fanatical and going to have high anxiety about it, get the pure sine wave. However, remember that consumer grade computers are designed to operate on the "dirty" power coming out of a wall socket since probably 90% of consumers are clueless about UPS's....so in my opinion, a stepped-wave UPS is good enough.

 

[imanidiot]

If you're really fanatical and going to have high anxiety about it, get the pure sine wave. However, remember that consumer grade computers are designed to operate on the "dirty" power coming out of a wall socket since probably 90% of consumers are clueless about UPS's....so in my opinion, a stepped-wave UPS is good enough.

Appreciate the thought. I have, as I said, been using a stepped-wave APC unit for three years, and it's done what I needed---filled-in little gaps when there are hiccups on the line, and shut down once when I lost power. I don't plan on trying to keep working during a power outrage, I just want something that will keep the iMac stable until it gracefully shuts down.

 

[Mr. McMac]

I've been using stepped sign wave UPS's on computers for 20 years with no negative affects. For high end audio and video, I'd recommend pure sign wave UPS's

 

[balamw]

Don't forget that everything inside the Mac is DC, and the first thing the power supply will do is convert the incoming AC to the required DC levels. There's no real analog circuitry in your Mac.

B

 

[Mr. McMac]

Don't forget that everything inside the Mac is DC, and the first thing the power supply will do is convert the incoming AC to the required DC levels. There's no real analog circuitry in your Mac.

B

I would say you're probably right assuming the audio chip is class D and not AB or B.

 

[balamw]

I would say you're probably right assuming the audio chip is class D and not AB or B.

Putting it another way. I don't believe there's a pin on the PSU harness for anything other than the DC levels generated by the switcher and ground.

Of course the noise levels generated by the switcher will be different depending on the quality of the input.

B