AC/DC questions plus BMU ones

[Ithilstone]

Hi kimangelis - I didn't say I want to - I asked if it can be connected - and Doc gave me simple answer with simple explanation why it is a bad idea.
I never worried about my PC till electrician said how far from ideal my mains are...
I already ordered some surge protectors and I will have a think about getting UPS

[Geoff.R.G]

I am no fan of desk top computers so I mainly use MacBooks, which come with a built-in UPS, better known as the battery.

The problem with surge protectors is that you have no means of telling whether the varistor has been fried or whether it is protected from damage. That isn't to say that they are no use, simply that you need to get a good one and probably replace it regularly or have it tested.

[kimangelis]

Hello Ithilstone.

Fair enough... this is all you need, and it has the auto shut-down facility.

https://www.maplin.co.uk/p/sweex-pp-200 ... -ups-n88nf

[zebbo]

I have my BMU plugged into a Powerinspired mains regenerator. I had the regenerator first and then, after various reports of it not being required after buying my BMU I sold it. Without it, every day at certain times ALL the transformers in my hi-fi gear would start humming including the BMU itself. Regardless of whether or not it made an audible difference that doesn't seem right so I tracked down and bought another regenerator and put it back in place - no more noisy transformers! I've listened with it in place and without and can hear no difference so it stays in.

[kimangelis]

That's interesting. I live in a rural location and the mains is about as stable as a chocolate fireguard. The transformers on my A70's and my BMU both buzz slightly but this is not audible when listening. What does a mains regenerator do exactly? I'll do some reading of course but wouldn't mind your input.

[zebbo]

I haven't a clue what the actual problem is on my mains and I also haven't a clue how the regenerator stops it but it does. Having pretty much zero knowledge of electronics I just went with my gut feeling that if something is designed to operate at 230v 50hz then why not give it the most stable 230v 50hz you can? It must make the equipment's life easier surely, regardless of whether it can handle wayward mains or not? Anyhow, as I say, I can't hear any difference with it in place and all my equipment runs quietly so it remains. BTW, when I say the transformers would start humming, I mean you could hear them 10ft away.

[Dr Bunsen Honeydew]

It does what it says on the tin - regenerate = to generate or produce anew. It makes new mains out of old mains, it converts the AC to DC and then reconverts back to AC.

The cheap ones notably Power Inspired do some thing good and other things bad. The multi £thousand rip off ones it seems I am told only do good. MartinT and another member at TAS have the PS Audio P10 regenerator at £5000 and the P5 for £3500 and keep saying how good they are.

http://www.psaudio.com/products/p10-power-plant/
http://www.powerinspired.com/store/ag15 ... -1742.html

[Geoff.R.G]

Back in the mid 1980s Boeing offered the 737-300, 737-400 and 737-500 with generators called VSCFs (Variable speed constant frequency). These devices were basically a three phase generator a rectifier and an inverter, per phase, that apparently produced a very clean output waveform. I can't comment on the waveform as I never saw it but the price was significant. I take from this that it is possible to recreate a clean sine wave using electronics but doing so isn't cheap. Are you prepared to spend that much money for a clean power supply for your Hi-Fi?

The other question is "does it make £5,000 worth of difference"?

[savvypaul]

My BMU buzzes a few times a day but the A80s never buzz. I stick the BMU out of sight behind a chesterfield chair. I was thinking of putting it inside a case with noise cancelling panels, but it's just a few times a day so not really an imperative.