“Pure Sine Wave” UPS for HiFi? [Archive]

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CageyH

11-03-2023, 11:25

Following my recent power problems, I started looking at mains regenerators.
I stopped quickly when I saw the prices.

Recently I purchased a NAS, and a UPS to power it.
It is a rebranded CyberPower PR1500LCD from what I can make out. My NAS recognises it as that model.
If it has a pure sine wave output, then surely this would be suitable for HiFi, and if not, why not?

The price is much more acceptable. Have a look on Amazon for the Pure Sine Wave Commercial UPS.

struth

11-03-2023, 12:21

might be ok up to a point. the power is a bit of a ? depending on which unit u get. its not a true regen i dont think tho

CageyH

11-03-2023, 13:14

I checked the price. It has gone up €300 since I bought mine.

struth

11-03-2023, 13:43

I checked the price. It has gone up €300 since I bought mine.

the regen? yes i guess they were fairly cheap so not surprised that when audio folk get interested the makers then bump up the cost...:doh:

CageyH

11-03-2023, 13:55

No, the UPS I bought for my NAS.

I dug out my regen. I have left it plugged in overnight, and used it to charge a battery.
The whining noise has gone?

I did clean it before I put it away, but can’t explain why it is not whining anymore.

struth

11-03-2023, 14:39

CageyH

12-03-2023, 10:05

I am happy to report that my AG1500 is silent once again.
So it is plugged back in to the system for the sources only. I am pretty sure it could cope with the power amp too, as I hat has some serious capacitance available for the power supply - 4 X 22000 uF per channel from memory.

CageyH

13-03-2023, 12:36

If my AG1500 does not have enough load, then it makes a whine. As soon as I load it a bit more, it is silent.

CageyH

14-03-2023, 09:01

It is weird, and I cannot explain it.
My AG1500 has my pre amp, phono stage, cd player, DAC, Digital Interface and T/T connected to it.
When I power it on with the phono stage off, it makes a noise. As soon as I power up the phono stage, it goes silent.

I plugged in my power amp to see if the increased load helped, and it didn’t.
My phono stage has a Schaffner IEC filter fitted to it. Could this be the difference?

struth

14-03-2023, 10:29

could be its maybe somehow feeding back into the unit when off. is it possible to switch iec's

CageyH

14-03-2023, 10:36

I think I am going to fit a Schaffner filter to my extension block.
It is a Furutech eTP60-e.

CageyH

15-03-2023, 09:11

So I tried a different power block. Same problem.
Different connection on the AG1500. Same problem.
DC blocker on the output. Same problem.
Power Amp also plugged in. Same problem.

Phono stage turned on, no more buzzing.

I have fitted my Amazon Commercial 1500VA “Pure Sine wave” UPS. No buzz from the unit, and no buzz/hum from the system.
I may have the answer to my problem, but I have also ordered some Schaffner IEC filters for the mains block and power amp.
I will try these before I order a new Pure Sine wave UPS.

struth

15-03-2023, 09:16

could dc be feeding back into the unit from the filter when off??

CageyH

15-03-2023, 09:21

I have also removed the phono stage completely, and the AG1500 still buzzed.
I guess I could also try an unfiltered IEC on the phono stage to see if the “buzz” from the system goes away.

CageyH

15-03-2023, 10:26

The system sounds a bit flat through the UPS. So, one less thing I need to purchase. :)

CageyH

15-03-2023, 10:37

I am going to unplug the power line network adapters at lunch time, and see if that fixes the noise.

struth

15-03-2023, 10:54

a lot of these regens etc can flatten the sound; possibly they level out the power too much