How Do I Install An LED To My Amp Head

[sunracer4]

Im overhauling my head and i put plexi on the front and i want a colored LED to light up my head! anyone know?

[Baxtercat]

Me too....I've been wanting to put more eye-candy on some builds, but know nothing about the things. It's gotta be easy; there are all sorts of voltages to hook up to.

[Sir Cuitous]

Yup I thought about it too but never tried it yet. I did find these automotive bulbs a few months ago online but haven't ordered.

BA9S miniature bayonet auto led lights

Wonder if they will work in an amp?

[PremiumPlus]

Just use Ohm's law...R=E/I...usually LEDs run around 20 ma or so, and 2 or 3 volts, so for 120 volts line current it would be 120-2 = 118/.02 = 5900 ohms, 3 watt resistor in series with the LED. Round up to the next standard value resistor. P = E*I = 118*.02 = 2.36 watts...again, round up to the next available power specification that's handy. Plug in the voltages and adjust to taste...you should be able to find a way lower source voltage than line current somewhere, in the amp and it doesn't take much power to light up a LED.

[tedmich]

Uhhh you'll need a diode in there to run an LED off of AC right?



allelectronics.com has some nice LED strands cheap

[PremiumPlus]

Why the back to back diodes and series capacitor? The LED is a diode in itself and it doesn't need filtering or dc to operate...It doesn't care. All I've ever done is a simple current limiting resistor, and so far I have had no trouble. YMMV

[Steve Casas]

Just tap off the 6.3v heater supply... probably won't even need a resistor with most LED's...just don't put more than 10 or so and you'll be fine.

[JHow]

Or, use the LED to bias your cathode in your tremelo... and watch it blink.

[Albert Kreuzer]

Why the back to back diodes and series capacitor? The LED is a diode in itself and it doesn't need filtering or dc to operate...It doesn't care. All I've ever done is a simple current limiting resistor, and so far I have had no trouble. YMMV

The only way I ever killed an LED was by omitting the reverse diode. LEDs are diodes, but they don't like reverse voltage.

The cap is a frequency-dependent resistor. It helps to drop voltage (without getting hot).

Cheers,
Albert

[hardcorekid]

Can i do all of this stuff with a blacklight instead of an LED? and can someone post a video or like a step by step that shows how to do this because i dont know what all of this means but id love to try it with my amp head

[mooreamps]

The only way I ever killed an LED was by omitting the reverse diode. LEDs are diodes, but they don't like reverse voltage.

The cap is a frequency-dependent resistor. It helps to drop voltage (without getting hot).

Cheers,
Albert

I would tend to agree. They don't have much of a backbone when they are reversed biased. But, I would put the rectifier diode in series with the led. The rectifier diode would take the brunt of the reverse voltage drop, and limit the reverse current through the led..

Then, if the heater supply is A/C, you could tap off the heater supply safely. Also, if your looking at the Ultra-Bright Led's, 2 to 3 mills of current is about all you need. Also makes the series resistor and/or the series cap easier to source.

-g

[R ski]

What PremiumPlus is correct, however, I would much rather use ohms law with tapping off the filament supply, this provides isolation on the primary feed of your amp, so that would be either 6 or 12 volts to to detirmine the voltage dropping resistor

[olddawg]

Does your PT have any unused secondary taps, like a 5v or 20v?