Non-audiophile mains regenerators?

Mister_Tad

Well-known Member
Aside from the Power Inspired units, do these exist? Is there another name for something that does AC->DC->AC conversion when they're not in the context of audio?

I've recently moved into a house which has various electrical quirks (don't worry, electricians have been called as well).

One of the quirks is that the transformers in two of the amps buzz quite audibly, and there's a hum on the speakers. So too does my sub make an ear-to-a-seashell sort of noise that it never made in the last place. I confirmed the theory that it's due to questionable mains supply by picking up a small online UPS - no such problems when plugged in through that.

Whilst an electrician may be able to diagnose and address any issues with the mains supply, the mains still comes into the house quite hot, and this in itself can cause the transformer buzz, so it got me looking at mains regenerators.

These seem to come in two flavours - audiophile and not. There are plenty of AC regenerator units out there from PS Audio and their kin whose descriptions and specifications are laden with audiophile tropes and price tags to match and they hold no interest to me - I don't want to start a debate about their benefits or not, just to say that a mains supply that's not garbage from a relatively los cost UPS resolved my issue, so I have no need for anything theoretically better than that. A much larger UPS could form a permanent solution, the battery component adds weight, maintenance, heat, noise and just isn't needed.

The Power Inspired units seems to tick all the boxes, though availability isn't great - are there any alternatives out there? In a commercial/industrial context do these have a different name that my google-fu hasn't come across? As surely "AC regeneration" is a valid need for all sorts of areas other than audio, but the search term "regenerator" only picks up audio products.
 

Conrad

Moderator
I've looked in to this a little.

I've used a sine wave UPS which did next to nothing for me.
I've also used a mains conditioned which also did nothing other than look pretty.

I've confirmed DC on the line which made some of my large toroidal transformers buzz. That was cured with a DC blocker from ATL Hifi - Combined module DC Blocker (trap, filter) & EMI/RFI/Common Mode Filter – Assembled in Case | ATL Audio Ltd.

Like you I wasn't prepared to spend £6k on an extension lead and I wanted something with a firm root in electronics rather than crystals and hyperbole.

I'm also interested in one of these: Conditioning Balanced Power Supply Transformers | Airlink Transformers but the ATL ones have solved my issues for now so I've got no reason to spend any more.
 

Mister_Tad

Well-known Member
Oh, and FYI, this was the UPS I bought, it's silent: CP1500EPFCLCD-UK, CyberPower CP1500EPFCLCDUK 1500VA | Box.co.uk

So that's a line-interactive UPS, i.e. it effectively operates in bypass mode when its on mains - so it's not surprising that it didn't do anything for you.

The UPS I used to test my theory was this one - Amazon productView: https://www.amazon.co.uk/Makelsan-ONLINE-1000VA-900W-TOWER-Orange/dp/B08CVRF1Y8/ref=sr_1_1?dchild=1&keywords=makelsan&qid=1607513431&sr=8-1


Was the cheapest, sine wave, online (i.e. is always effectively "regenerating" mains from DC, as opposed to switching between like a line-interactive) UPS I could find with short availability.

Since I'm having trouble getting hold of AG1500s, I'm going to try to determine whether the noise is from over-voltage, DC or just general mains ropeyness - fixing one of those may be easier, cheaper and more practical than a mains regenerator that fixes all of them.

In lieu of AG1500s, for regeneration I think the Power Inspired VFI6000RT+ is the bit of kit for the job. Since it's noisy it's going to have to go somewhere else, so may as well get a big one that needs to be hard wired anyway. Power Inspired have confirmed that it can run without batteries as well, just with a warning message on the screen, which I won't see since it will be in a comms room halfway across the house.
 

Conrad

Moderator
When I say it didn't do anything, I checked with it running on battery as well, no dice.

I don't remember how I found out that my issue was DC. Either the UPS told me or I guessed and tried the ATL thing. Worked like a charm for me though. I ended up buying the bigger one with dual sockets and running both my power amps off it.
 

Mister_Tad

Well-known Member
When I say it didn't do anything, I checked with it running on battery as well, no dice.

I don't remember how I found out that my issue was DC. Either the UPS told me or I guessed and tried the ATL thing. Worked like a charm for me though. I ended up buying the bigger one with dual sockets and running both my power amps off it.

That's weird, I'd have thought running on battery, your DC problem would have gone away.

I think my primary issue is over-voltage, so will try to address in isolation first - I have a stepped variable transformer packed in a box still somewhere that I'll need to dig out. I'm pretty sure the second-to-top step is 208v from 230v, which should translate perfectly to right on 230v from my low 250s mains.
 

Conrad

Moderator
You're right, I must be mistaken.

It's DC on the mains which means if I was running on battery there's no mains. Maybe I did different tests. It was a year or two ago now so I don't remember well. I had multiple issues (amp hum, sub hum) and they were all caused by different things!

My processor used to give me a read on what input voltage I was getting, as does the UPS. I was lucky that I'm very stable on 230.

Good luck trying to run it down. I'll be interested in your thoughts on the regenerator. I'm concerned about limiting dynamic range with anything like that. I have four 1000w subs (peak 2000w each) and amps that, on paper, could pull 4.2kw from the wall. I'm sure I'm not using anything like that of course.
 

Mister_Tad

Well-known Member
You're right, I must be mistaken.

It's DC on the mains which means if I was running on battery there's no mains. Maybe I did different tests. It was a year or two ago now so I don't remember well. I had multiple issues (amp hum, sub hum) and they were all caused by different things!

My processor used to give me a read on what input voltage I was getting, as does the UPS. I was lucky that I'm very stable on 230.

Good luck trying to run it down. I'll be interested in your thoughts on the regenerator. I'm concerned about limiting dynamic range with anything like that. I have four 1000w subs (peak 2000w each) and amps that, on paper, could pull 4.2kw from the wall. I'm sure I'm not using anything like that of course.


This is the problem... diagnosis seems to amount to trying different bits and hopefully figuring it all out before you've spent a fortune on superfluous gear.

I'll be conservative in sizing anything according to the power supply ratings on the gear - this

My SMPS-based NHT amp seems not to be bothered about power quality, so hopefully the Hypex-based amps on my shopping list are the same and can live plugged into the wall. So 6Kva if I go down the UPS route should be more than enough, though given the modest cost difference I may opt for 10Kva if that turns out to be the solution - I have a bunch of IT gear that runs on a handful of smaller UPSes and it would make sense to consolidate that too.

On the other hand, maybe one day an electrician calls me back, comes to the house, and finds a 10 min fix for the lot...
 

Conrad

Moderator
On the other hand, maybe one day an electrician calls me back, comes to the house, and finds a 10 min fix for the lot...

Directional fuses! :D
 

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