How to light up Tube/Valve with LEDs?

[cnspedalbuilder]

Hi, I've seen cool shots of Valvecasters and similar pedals in which people used an LED to illuminate the tube like this one:


I feel like this is a dumb question, but how do you do that? I've tried just sticking an LED in the guts but the light did not do much for the 12AU7.

Also, how do you wire it up? Do you wire the LED to a 3pdt or to a pin from the tube?

Thanks as always!

[Kevin Mitchell]

Who's telling you there's LEDs lighting up those tubes?

It's not unusual for tubes to glow that way - especially as result of photography and trick lighting.

(russian subminis in a well lit room)

I could very well be wrong! There could be some LEDs in there. Tis' only my thought.

[rutabaga bob]

You can use a socket with the open metal center tube, putting the LED up inside...can't remember which size fits, I think it's the 3mm.  Wire it like a regular external indicator LED.  You might have to use a dab of something to keep the thing in place...solidcore wire assists as well. 

[PRR]

Tube glow is not enough for some people.

The BLUE glow in the picture in the first post is either an incredibly sick (gassy) 12A?7 or an LED added.

The usual way is to drill the center of the socket for a high-intensity LED.

[merlinb]

As noted, you use a valve socket with a hole in it and put a 3mm high-intensity LED in there. Standard-brightness LEDs are often too dull to get a good effect. The subminis probably just have an LED pointing at them from within the enclosure. The glass has a light-guide effect that helps to diffuse the source of light somewhat.

[cnspedalbuilder]

I thought the answer might be to pop the LED into the socket, but the 9-pin belton socket has a small hole. Sounds like it should be ok to drill it out a little if necessary. Thanks everyone!

[HeavyFog]

I usually use brown plastic sockets and drill out the center hole so i can fit a 5mm LED in there. A drop of epoxy or hot glue and your done. High brightness LEDs seem to work best. Orange LEDs give it a neat "fake glow" and violet looks really great as well. I bet you could do some really neat stuff with a dual or even tri colored led

[merlinb]

I thought the answer might be to pop the LED into the socket, but the 9-pin belton socket has a small hole. Sounds like it should be ok to drill it out a little if necessary. Thanks everyone!

Often the shoulder of the LED won't fit into the hole, but that doesn't matter with an ultra-bright LED. Just poking the rounded part of the lens in is enough.

[rutabaga bob]

Try a 3mm...

[cnspedalbuilder]

Thanks everyone. One more question--if you wanted the LED to be independent of the bypass switch, is there an easy way to set it up (e.g., can you do it on one of the tube socket pins)?

[rutabaga bob]

If you just want it to be lit all the time, you can run your LED resistor from the D.C. jack directly, making sure you have the correct value for the supplied voltage (9 or 12 volts).  I suppose you could run it from the heater pin with the positive voltage...don't know if that would cause any interference/noise.  Remember, the LED will stay lit as long as you have power going to the pedal.

[merlinb]

Thanks everyone. One more question--if you wanted the LED to be independent of the bypass switch, is there an easy way to set it up (e.g., can you do it on one of the tube socket pins)?

Yes you can feed it from the heater pins (with a suitable resistor).

[Kevin Mitchell]

Just threw together a board for prototyping a tube project and gave the LED idea a try. I used black plastic pcb mount sockets and 3mm clear/bright LEDs. The holes in the sockets needed to be expanded a little to fit the whole LED. Way cool