does an indicator led work on AC?

[birt]

i'm building a preamp with a built in footswitch. can i use the heatervoltage of the 12ax7 for indicator leds?
or do i really really need DC because the led will explode or something?

[zachary vex]

with a high enough current-limiting resistor there's nothing to worry about.  open up any modern cheap power strip and you'll see there's nothing but an LED and a resistor in that circuit, and it's fed with 110VAC!

[Gilles C]

Some info here:

http://www.eng-tips.com/viewthread.cfm?qid=107410&page=1

And somw more here:

http://ourworld.compuserve.com/homepages/Bill_Bowden/page10.htm#lineled.gif

You have to make sure you don't go higher than the max reverse voltage the LED can support.

[birt]

with a high enough current-limiting resistor there's nothing to worry about.  open up any modern cheap power strip and you'll see there's nothing but an LED and a resistor in that circuit, and it's fed with 110VAC!

what resistro would i need for 6 or 7 VAC?
a 1k like i use with my 9VDC pedals?

[niftydog]

assuming 7VAC RMS, the equivalent DC power is about the same, actually it's a little less. If you use a 1k for 9VDC, then the same ratio is approximately 750ohms for 7VAC.

[Paul Marossy]

I've used LED indicators in my last three tube builds. All of them were powered off of the 12.6V heater circuit.

Oh, and I used one on the two Shaka Tubes that I have built, powered by the 12VAC before the voltage doubler circuit.