Discoloured Knob

The volume control knob on my Nait 5 has turned this dark coppery colour - is there any way to repair/restore this to the original black? Or is replacement the only successful option?

Can I be the first to say… after the headline, that’s SO disappointing?



Looks like someone’s been polishing their knob with something they weren’t supposed to.


Wow, I’ve never seen one go that colour! You could try a re-spray in flat black. It has to be better than that. Otherwise, replace it.

There must be a story with this. Has it been left in the sun?

If you have to remove to respray you might as well just replace it. A pain though.

I thought they were black plastic so same colour throughout?

What material are knobs made of?

I think the inner part is plastic with an alloy outer skin.

Screenshot 2019-12-28 at 19.02.51
Oooooh Matron

I think you need a replacement knob


Its quite a nice patination, it just needs the Naim logo to be the same golden colour rather than the green and it would like great.

I always say that the black is too lazy from a design point of view and perhaps even a slightly greyer black would at least give the boxes a little more character.

If I rub my knob will it turn that colour?

It’a a crying shame that Naim amps don’t have bottoms as well as knobs (or do they, I wonder?), so we could all fall about laughing even more!


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Is your Knob powered by Duracell? I would personally look seriously at replacing your Knob with a black one.

Spraying your Knob will likely result in bits flaking off due to poor adhesion.

New Knob or leave it alone! Were you rubbing it too much? :laughing:

I’d just have it replaced, can’t be too much hassle to do…carefully pull off knob, gently take out LED. Reverse assembly with new knob.


Interestingly I have seen the front face of the piston of some KEF B139 drivers - originally black - become a very similar colour after several decades. The front face is an aluminium skin laminated to the expanded polystyrene piston, treated in some way to make it black. From its appearance when new I always assumed it was a black plastic film, however perhaps the aluminium was anodised. Either way it may possibly be an identical surface material to the knob in question. That suggests a possible long term atmospheric effect, happening only in some locations. Unlikely to be oxidation but perhaps due to a contaminant in the air, such as a trace of sulphur dioxide which is a common pollutant.

@Richard.Dane @Thegreatroberto @Dan_M @Innocent_Bystander

Thanks for your comments. I bought the amp second-hand and it arrived like this. I have seen other amps (like Rotel) in our local auction site with the same thing.

If the knob is aluminium (skin?) as suggested, it’s quite likely the harsh New Zealand UV laden sun has caused this. The red anodised bits on my Triumph have faded to pale pink over time as well. Will price up a replacement

@ everyone else - I thought the headline would provoke these kind of responses, very droll!

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