My father just bought a new amplifier (Cayin 252B), and somewhat to his dismay, it sports some absolutely killer LEDs. I normally kind of like little lights on stereo boxes, but these are just too much. I suggested he paint over them, but he’s worried the heat from them might “burn” the paint in some way, and of course, painting your stereo is rather drastic. Would it be a risky procedure to open the box and unplug them?
Oh, and he doesn’t want to remove them either, as they’re the only thing showing that the amp is on. So the question isn’t about disconnecting them, but replacing them. Or, painting over them.
(You should see these. They’re plain sick)
I have the same problem with a blue LED on a hard drive. I put tape over it, but it’s sort of ugly.
Heat? From LEDs?
I would be very surprised if they got warm at all. Even a bright LED uses much less energy than an incandescent or fluorescent bulb.
Very probably, you’d have to unsolder them to disconnect them. And removing them might have a bad effect on the functioning of the unit (not 50% likely, but you’d have to go through the electronic schematic of the amplifier’s circuitry to make sure).
What would make sense would be to replace the LEDs with dimmer ones. You’d still need the schematic, parts lists, and LED-manufacturer’s spec sheets though, to determine what kind they are and what suitable drop-in replacements might be.
You can probably get by with just cutting tiny pieces of tape to fit over the LEDs to dim them.
LEDs may be efficient, but the energy released as light is still a small fraction of the energy consumed. Which means if you paint or tape over it, it’s not going to get any hotter than it is.
Another option might be to take a file or sandpaper and dull the tip of the LED. LEDs are usually encased in a clear plastic, and the rounded end of it acts as a lens. Roughen up the surface and it acts like a frosted glass instead.
You could always stick a series resistor inline with the LED. Drop the brightness by almost as much as you want. Google for “led resistor calculator” to find out what you need to do. You should be able to find approximate figures for the current of the existing LED on those pages too - it’s probably a high-brightness type.
tim
Or do what I have done in this situation, and disconnect one leg of the LED and solder a current-limiting resistor between the leg and the original point of contact. The value you need depends on a number of variables, but going with ~100 ohms is a good place to start. The current will be only be in the neighborhood of 10-30 mA, so you can get away with 1/4-W resistors with no problems.
Tried to Google it up, but apparently none of the pages are in English, so no luck for me there.
Anyway, you might want to check to see if they kindly provided a switch somewhere to turn off the fancy light display.
I once whined to a co-worker about how annoying the flashy blue lights on my Netgear router were (we had both bought the same model). After I told him of my attempts at masking the blue at night, he laughed and told me that there was a pushbutton on the back that turned off the lights. He was right.
The rackmount server cases we’re getting seem to be coming with bright blue LEDs these days.
I put clear tape over them, then colour over it with a black marker. Blends in, indicates power status quite well, and I don’t get blinded when I try to use the KVM now.
I have a few stereo components with blindingly blue lights. I’ve been meaning to put a dab of clear silicone caulk on them just to see if it helps diffuse the light a little.
I have Electrocompaniet pre & power amps and had a similar complaint about the blue LED on the preamp that is a volume indicator. (May be a Scandinavian thing 
). Annoyed the hell out of me for a while until I discovered the cunningly concealed rheostat beneath the chassis.
A decent HiFi or electronics servicing shop would likely be able to fit a similar rheostat to your amp.
That works fine. Unless the LED is powered from a constant current source. Which is becoming more common nowadays.
If it is powered from a CC source, the resistor would need to be placed in *parallel * with the LED.
I’ve seen LED covers - they’re like tiny little plastic condoms designed to slip over 3 or 5mm standard LEDs - I believe they’re intended mainly for fitting over near-UV LEDs to convert them to other colours via fluorescence, but I think they might have been available in other colours to attentuate unwanted brightness.
I despise the current trend for putting a too-bright blue LED on any and every bit of consumer electronics. I’ve used a little dab of red nail polish on some of them to calm them down a bit.
I had a radio shit clock radio with blue LED time numerals that lit up the bedroom at night, even on “dim” setting. I got some window tint sheeting and put 2 layers of it over the face. Solved the problem.