Actually that’s breakthrough rather than RFI.
The type of ferrite chokes I’d recommend are those made by Würth Elektronik.
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No hum on any of my equipment. 10mm radial circuit fitted via a seperate consumer unit.
If a dedicated radial circuit reduces hum for a transformer, that indicates that something in your own house is causing the problem!
You should probably also track down the source of the problem as it’ll may also be causing other problems in the mains as well!
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Not a fan of Ferrite, i’ve always found it rolls off the highs… but that’s just me. If my brand new amp hummed that loudly I think I’d take it to my dealer and ask for an exchange.
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A bit strange if that is the case, the lowest frequency any ferrite starts to become effective is 150kHz. Even bats hearing doesn’t go that high.
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I can only comment on my experiences.
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Agree. I had 3 HCDRs over the years. One hummed like a loud humming thing, and two not. All on the same mains.
G
Ferrites can reduce the RFI that can lead to a more ‘brittle’ sound; removing that can appear to be a HF roll off.
Hi Xanthe, I’m aware of that, but there are more myths about what ferrite does & doesn’t do than fleas on a dog, probably never change, but no harm trying.
another example of the xxx cases when there are disparities between same components.
Why not?
New kit should not have intrusive hum. It really doesn’t help the OP if somebody else accepts hum and somebody else’s doesn’t hum.
It is extra expense, but I’d try a MCRU In Line DC Blocker. It’s not too pricey and you can return it if it doesn’t work or you simply don’t like it. There is BF’s Airlink and other devices from Power Inspired, Isol-8 Axis and IsoTek Syncro at various prices, which again may address the problem.
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But your idea of intrusive, is different to another persons intrusive. I have varying degrees of hum, but not fussed as long as I can’t hear it metres away.
For example; I am on a dedicated circuit - but If I put my ear to each power supply, some are louder than others. What am I going to do, send them back because some are louder? no, of course not. However, if my wife uses her hair dryer, they all sing…
It’s hard to know what’s an acceptable level, perhaps I’m being over fussy or perhaps not, I’ve no reference other then my Nova which is completely silent. Right now I’m sitting on a sofa about 3m away and with no other background noise I can just about hear it
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How far are you from a dealer? there is no gaurantee that taking it there will allude to anything (as their mains supply will be different). It might even be worth a bit of trial and error and see if there is any other location you could test in your digs. Just sayin.
Yeh I’m going to try it in a few different places over the weekend and see. It does sound rather nice though apart from the hum!
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Yeah, might be worth a try. Less inconvenience moving it around vs dealer visit etc. If the hum is consistent throughout your place, at least that gives you some indication.
if you hear the hum more than 1 meter distance, continuously, i would personally ask for a replacement.
My 555 dr was humming specially on night, but not always. Hopefully never during day. But i found it already annoying. I could however not hear it more than 2 meters.
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Hollow said it was annoying, so I was trying to make it less annoying for him. I agree it may not annoy you. I changed my kit to avoid buzzing transformers, but that’s a drastic solution.
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Some manufacturers pot their big transformers within a hefty encasement to eliminate hum. For me any hum is unexceptible.
Reminds me of the trouble I had when I bought two Technics SL1200s, and one of them had a transformer hum.
Mixing between my favourite discs was plagued by the introduction of hum. When I tried plussing the dealer about it, they were not helpful at all. Put me off hum for life.
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completely agree. When you pay for a naim power supply which costs sometimes more than the component itself , and you have to hear it humming more than a chinese fridge, it’s simply unacceptable.
I had before 2 hicap, one was humming, the other not. Today, in a same situation, i would not hesitate a minute for a replacement.
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