Mains conditioner - home made as good as Isotek Aquarius

[RothwellAudio]

No it cannot be done safely without an isolation device because of the design of scopes
BNC which is wired to safety earth, this then extends out to the probe flying lead

Scope probes have the probe ground at safety earth potential. Grab a multimeter
and confirm close to zero ohms.

My scope's input can be grounded or floating. I thought that was normal for most scopes.

[anthonyTD]

Measuring mains voltage with any form of test equipment is risky at best, again, the safety aspect here was not in question!
A...

[blackstar]

Measuring mains voltage with any form of test equipment is risky at best, again, the safety aspect here was not in question!
A...

...and no-one 'chooses' to take a mains whack, do they?!

[RothwellAudio]

True, the OP's question wasn't about safety but idea of actually testing the quality of the mains makes sense to me.

[YNWaN]

Incidentally, one of the most effective ways I've found of reducing noise on the mains, which usurps that of anything discussed here, and which is rarely mentioned, is installing a dedicated earth solely for your hi-fi system, via the use of multiple copper rods [plunged into a damp area of your garden], which is tagged onto a separate mains spur (with consumer unit).

The installation of said dedicated earth almost completely isolates your system from noise/interference present on the standard house ring-main and earth, in a way that simply isn't possible with a separate spur alone, and subsequently allows your system to perform to its maximum capability. In my view, if it's practical to achieve in the property where you live, this should be done before the purchase of any expensive active mains treatments, as it could negate any need for their use at all.

Marco.

I used to have just such an additional earth at my previous home (as well as a dedicated ring) and did think it was of benefit. Mine was as well as the normal ring main earth and I presume that is what you mean Marco - you aren't suggesting disconnection of any earth bonding?

The music room in my current house is two floors up and the difficulty of routing the wire has so far discouraged me from repeating the earth idea - though I may still do it. However, the wiring in my house was relatively recently replaced and is very low impedance with very thorough earth bonding throughout.

[Light Dependant Resistor]

True, the OP's question wasn't about safety but idea of actually testing the quality of the mains makes sense to me.

Yes can be done safely by using a low voltage transformer secondary like 12VAC then interfacing with a scope , in effect you are then looking back at the mains quality.
via the secondary voltage.... such is the nature of AC. Lorentz theorem applies https://en.wikipedia.org/wiki/Recipr...ctromagnetism)

Cheers / Chris

[Marco]

I used to have just such an additional earth at my previous home (as well as a dedicated ring) and did think it was of benefit. Mine was as well as the normal ring main earth and I presume that is what you mean Marco - you aren't suggesting disconnection of any earth bonding?

Nope, most certainly not, as that could potentially be lethal! Simply that, having a dedicated earth for your hi-fi, which is separate from the ring-main earth, is a sonically beneficial thing to do

Marco.

[RothwellAudio]

Yes can be done safely by using a low voltage transformer secondary like 12VAC then interfacing with a scope , in effect you are then looking back at the mains quality.
via the secondary voltage.... such is the nature of AC. Lorentz theorem applies https://en.wikipedia.org/wiki/Recipr...ctromagnetism)

But you aren't scoping the mains if you do that - you're scoping the output of the transformer, and that isn't the same thing at all.

[Light Dependant Resistor]

But you aren't scoping the mains if you do that - you're scoping the output of the transformer, and that isn't the same thing at all.

No, if nothing else is attached downstream, due to reciprocity you are looking back at the mains via the electromagnetism properties of transformers.
Hence the transformer is coupling at a lower potential exactly what the mains is doing.

Think of disturbances from fridge motors etc these can be seen as momentarily upsetting the mains, and reflect almost instantaneously
as noise. Attach an electric drill to a mains socket, you will see all sorts of jagged waveforms when the drill runs. The same waveforms
will be seen on the safe secondary side of a transformer viewed with a scope, as exist originating on the primary side.

You are viewing alternating current originating from the mains because there is no other source. If viewed in a DC sense there is direction ie work transferring back
via the secondary neutral ie a load etc and therefore dissipation and difference of the original activity , but this is just AC measurement, hence because it is cyclic
it is a true reflection up to the coupling properties of the transformer - in this case at a lower and safe potential capable of being read by a scope. Thinking too
that the transformer is a low impedance and the scope a high impedance - the scope is not going to contribute to any error or possibility of loading the transformer down
rather it just faithfully reads alternating current from the mains source.

[RothwellAudio]

Thanks for the lesson in what a transformer is.
If I want to look directly at the mains with a scope, I will. I'll accept responsibility for my own actions if I blow myself up.