Mystery Box

[PH_UK]

Can anyone solve the mystery of what this box is? It was in my daughter's new house. Apparently the previous occupant was seriously into his hi-fi. When I took it off the shelf it was positioned on (already disconnected by having the wire cut), I was surprised to find it weighed a ton. I opened it up expecting some hefty transformers (I thought it was perhaps an inverter, and we were surprised to see nothing much.

The earth from the input cable connects straight across to the double socket, whilst the live and neutral disappear into the solid, very heavy block in the middle. I don't know if there are any electronics in there, but the whole thing is very heavy. It looks like whatever is in the middle has been coated with a black epoxy on top. It really is a 'black box'

Any ideas? There are no markings on it at all, to give a clue, which would suggest it's a home project perhaps.

 

[Revolutions]

That’s the transformer that lets you play the white album backwards & summon the devil.

 

[PH_UK]

That’s the transformer that lets you play the white album backwards & summon the devil.

Haha, well that sounds worth trying out - what could possibly go wrong

 

[Gray]

Any ideas?

Short of asking the previous owner, you're likely to be left guessing.
Certainly looks homemade - with that join? on the input wire.

You could measure the resistance across the input and outputs - if they're very similar, it could be a 1:1 isolation transformer .......

Think I'd have to chip away at the blackstuff.

 

[PH_UK]

Short of asking the previous owner, you're likely to be left guessing.
Certainly looks homemade - with that join? on the input wire.

You could measure the resistance across the input and outputs - if they're very similar, it could be a 1:1 isolation transformer .......

Think I'd have to chip away at the blackstuff.

Thanks. That was one of my suspicions, but not being a hi-fi expert I wasn't sure if my thoughts were rubbish. So the objective would be to remove noise from the mains input. I'll take my multi-meter round next time I'm there

 

[Gray]

So the objective would be to remove noise from the mains input.

Noise might get inducted through a TX, but DC wouldn't....for those where it's a problem (such as with some Audiolab amps?? - requiring DC blockers.

 

[daytona600]

Could be a DIY Grounding black £10k +

Ground Boxes | Entreq

Discover the Ultimate Audio Performance with Entreq Ground Boxes The principle behind an Entreq Groundbox is to provide a clean and solid ground point for ...

www.entreq.com

 

[daveh75]

If it were me, I'd find the nearest skip and throw it in!

Even if it is some kind of mains conditioner it will have zero impact on SQ, so not worth investing the time and energy investigating what it's supposed to do.

Not to mention the safety implications of using some random DIY kit.

Particularly if it's the work of some audiophile!

 

[Friesiansam]

Could be a DIY Grounding black £10k +

Ground Boxes | Entreq

Discover the Ultimate Audio Performance with Entreq Ground Boxes The principle behind an Entreq Groundbox is to provide a clean and solid ground point for ...

www.entreq.com

I would like to see a review of one of those boxes, one that includes a picture of the contents of the box.

 

[Dom]

 

[nads]

Snake oil.

 

[PH_UK]

Noise might get inducted through a TX, but DC wouldn't....for those where it's a problem (such as with some Audiolab amps?? - requiring DC blockers.

Thank you - that's interesting, I didn't know that a DC component of the mains might be a problem and I must admit I my I did wonder why noise wouldn't be inducted. I'm learning

 

[PH_UK]

If it were me, I'd find the nearest skip and throw it in!

Even if it is some kind of mains conditioner it will have zero impact on SQ, so not worth investing the time and energy investigating what it's supposed to do.

Not to mention the safety implications of using some random DIY kit.

Particularly if it's the work of some audiophile!

I have no plans on using it, but my curiosity was piqued upon opening it up With the whole thing being set in some solid block, it's impossible to discern anything about its safety.

 

[PH_UK]

I would like to see a review of one of those boxes, one that includes a picture of the contents of the box.

Those do look interesting, though you seem to have to take them on faith as they won't say much about what's inside due to not being able to get patents. This box doesn't have any grounding connections, so I don't think it can be that.

 

[PH_UK]

Hmm, sounds like there might be an opportunity to market our box as a 'quantum' mains purifier, with technology so secret it's been encased in unobtainium £15,000 anyone?

 

[Gray]

I didn't know that a DC component of the mains might be a problem

Not sure many people did.
And I doubt it's common.
Apparently the cause of loud mains transformer buzz in a few Audiolab 6000A amps.

I doubt what you have is just an isolation transformer though.

As has been said, best not to bother with it.
Someone might want the box on e-bay.

Russ A. could probably get £1500 for it as it is😉

 

[PH_UK]

Not sure many people did.
And I doubt it's common.
Apparently the cause of loud mains transformer buzz in a few Audiolab 6000A amps.

I doubt what you have is just an isolation transformer though.

As has been said, best not to bother with it.
Someone might want the box on e-bay.

Russ A. could probably get £1500 for it as it is😉

Funny you should say that, one of these was plugged into the socket next to it: https://www.russandrews.com/the-silencer/

 

[Friesiansam]

Funny you should say that, one of these was plugged into the socket next to it: https://www.russandrews.com/the-silencer/

Just looked at that. One customer has fallen for it, hook, line and sinker. Even thinks his TV has a better picture!

"these mains conditioners helps you get the best out of your system no matter what level your system starts at.....one conditioner works but the more you have the better so right now i have 3 in my mains sockets for the last 3 years so to be honest my 4k tv..Dvd player n my freeview box sound 100% better n my tvs picture has gained...so to sumup all your Electrical units will have their life exstended by at lease 5 years."

 

[nopiano]

Funny you should say that, one of these was plugged into the socket next to it: https://www.russandrews.com/the-silencer/

Perhaps it’s a BMU? For balanced mains.

Russ sells them, as do a few others, and they are very expensive. I won’t attempt to explain them, and they need to be wired carefully or can defeat fuses!

 

[nopiano]

After some googlage, I found an image very similar. But the link now goes to a newer model. And the website seems to be on hold as the owner has sadly died. But I reckon you have a Ben Duncan box, possibly a BMU.

British Audio Products Online - Ben Duncan's Products

British Audio Products Online - Suppliers of high quality audio equipment and accessories to audiophiles all over the world - Ben Duncan's Products

www.britishaudio.co.uk

 

[PH_UK]

After some googlage, I found an image very similar. But the link now goes to a newer model. And the website seems to be on hold as the owner has sadly died. But I reckon you have a Ben Duncan box, possibly a BMU.

British Audio Products Online - Ben Duncan's Products

British Audio Products Online - Suppliers of high quality audio equipment and accessories to audiophiles all over the world - Ben Duncan's Products

www.britishaudio.co.uk

View attachment 5584

Ah yes, that looks strikingly similar, thanks.

 

[Gray]

... probably tells you all you need to know that the previous owner didn't bother taking it, or the RA silencer 🤔.

 

[PH_UK]

Perhaps it’s a BMU? For balanced mains.

Russ sells them, as do a few others, and they are very expensive. I won’t attempt to explain them, and they need to be wired carefully or can defeat fuses!

I did read a little about BMUs on getting some of the responses here, and if it's one of those, it may explain why he cut the plug off, when presumably he stopped using it; just in case.

 

[PH_UK]

... probably tells you all you need to know that the previous owner didn't bother taking it, or the RA silencer 🤔.

I think he died. I imagine his wife might have sold some stuff perhaps. These two items were still there after the house clearers had emptied the place.

I suspect the power point this was next to (and had the silencer plugged into) will be on an isolated spur - there are at least three (from memory) distribution boxes.

This has all been very interesting, I now know a lot more about concerns with mains supplies and hi-fi equipment. Some of it makes sense and some of it sounds like snake oil. I wonder if my Alexa will sound more spatial if I plug into this?

 

[Dom]

I don't think the RA Silencer could improve audio quality, my best guess is it might remove the pop when appliances come on?