Sorry - Noisy Transformers Again - Advice Welcome - Update that could be controversial

[GadgetMan]

As a final confirmation, may be worth putting it back to how you started after say a week of getting used to it

[Innocent_Bystander]

I haven’t read the full detail of all posts here, but if it hasn’t been said already intermittent hum from the transformers is almost certainly DC on the mains, which could be coming from something within, or external to the home. The only solution is to find and fix the source(s) if within the home, or block the DC: two options for latter, a specialised DC blocker, or an isolating transformer. The latter is likely to be the more expensive.

More here:

Cables for Naim Statement

I think your solution is the bandage, and Naim’s might be the cure! (Albeit I am only guessing as to their suggestion.) I can’t answer your specific question, however it may be worth considering addressing the problem rather than your thought for a work around, if not already done. Ttransformer hum is most commonly caused by DC on the mains. That is particularly likely to be true if the hum is variable, sometimes suddenly increasing or decreasing. There are two solutions for that, to remove the…

[Mike_S]

@Neilb1906

Infact it shows that a dedicated mains isn’t the cure in all cases.

Yep, if it’s coming from the street or wider network, that dedicated mains won’t do anything.

[GraemeH]

‘Isolate PowerLine Axis’ dc-blocker completely eliminated my intermittent hum/buzz issues.

G

[JimDog]

@AWillby

Isotek Evo3 Isoplug

So - to confirm - you plugged in the IsoTek EVO3 ISOPLUG to the first of 6 UK wall sockets that are wired up in series on one dedicated hifi radial.

And you moved all your hifi equipment plugs to the other (later in the chain) 5 sockets.

And this made an audible improvement to SQ, as well as significantly cutting (but not eliminating) transformer buzz on your Naim system?

i.e. the IsoTek EVO3 ISOPLUG cleaned up the electrical feed - presumably by DC on the line?

And - speculating - the improvement in SQ was probably due to lowering the electro-magnetic noise floor?

Jim

[AWillby]

Hi JimDog

Three double sockets in fact. Didn’t do anything other than unplug the Xerxes ps and replace it with the Isoplug. Clearly whatever it does is proving beneficial to the system. It was a noticeable change for the better. Had I been in the business of upgrading my XPS DR with a 555 DR I would have been very happy with such a result.

[AWillby]

Thanks for the tip. I will investigate that device - might totally eliminate the transformer noise. As I explained in the first post it had only become annoyingly audible very recently. I think it was external - though I live in a residential area - who knows what goes on. All quiet in the main again now.

[AWillby]

Thanks for the link. I’ll have a look at the MCRU DC blocker mentioned in the other post you linked to. Always nice to know there is another level you can go to if necessary.

[Neilb1906]

A cheaper option is the DC Blocker from ATL Audio. Good if you already have a quality multiway.
About £100 delivered from Bulgaria, but a credible company. I and a few other members here have had good results with it.

[Innocent_Bystander]

@JimDog

i.e. the IsoTek EVO3 ISOPLUG cleaned up the electrical feed - presumably by DC on the line?

As far as I am aware that device isn’t a DC blocker - and it didn’t stop the transformer noise…

[JimDog]

@AWillby

Had I been in the business of upgrading my XPS DR with a 555 DR I would have been very happy with such a result.

Thanks.
To clarify - are you saying that the SQ uplift from adding this IsoTek EVO3 ISOPLUG was what you think you’d get from replacing an XPS with a 555DR?

[Innocent_Bystander]

@AWillby

it had only become annoyingly audible very recently.

Could be external as you suggest, but it could also be something within your home that has developed a fault. Separate distribution unit and cabling doesn’t of itself block the DC from the rest of the house attached to the mains. However given a dedicated supply, checking if it is from your own home is easier than unplugging everything else: you could switch off the power to the rest of the house at the distribution board. If that stops it then you know its from your home and you could go through to try to find the culprit, as described in the link in my first post in this thread

[AWillby]

No as I have never done the comparison - just saying that had such a change delivered the uplift I seem to have gained I would have been happy.

[AWillby]

I did check all the normal culprits as they mainly all live in the kitchen and utility room. Did it in a noisy period - made no difference. I’m certain it was external to my house. Things have been back to mainly quiet for the last few days.

[Blackbird]

Interesting. Is that a clean DC blocker or other filters included?

[GraemeH]

No filtering that I’m aware of. Its a 5 way block designed by an ex BBC engineer.

Not cheap but I find it works as described on the website with no downsides.

G