Powering a backlit emblem on speaker cabinet

[hesamadman]

I built a speaker cabinet with a badge that I want to be back lit. I was wanting to get a power source to the LED behind the badge. I figured I could use a regulated power supply from my heaters. One that would be used for a relay. I thought I could wire the cabinet in a way to where there are two jacks on the back of the cabinet. One would be a standard 1/4" speaker jack for the cabinet and the other jack could be for the LED. I was thinking maybe an RCA? So the back of my amp head will obviously have a 1/4" for speaker out and an RCA out to power LED. So when amp turns on, the badge on cabinet lights up. Does anyone see any problem with this if I use regulated DC and keep these wires separated from speaker wires? Also, I do not want to use two 1/4" jacks because I don't want any confusion and hookup the speaker load to the DC supply or vice versa. So I figured an RCA jack or if anyone has any other suggestions?

[kagliostro]

I think it will be more simple to have a rechargeable battery on the speaker cabinet to feed the LED


Franco

[hesamadman]

That would definitely be simple, but I'll go the extra mile here.   
Probably just going to take some experimenting.

[sluckey]

What you propose will work. There's no problem having the LED wires close to the speaker wires.

Something to think about... Power the LED with a small wall wart that plugs into the wall. Then you can light up your badge regardless of which amp you use.

Any way you do it, you must use a current limiting resistor in series with the LED.

[MakerDP]

Something to think about... Power the LED with a small wall wart that plugs into the wall. Then you can light up your badge regardless of which amp you use.

I was going to suggest this same thing. Way easier and you were going to have a wire connecting to the cabinet anyways.

[PRR]

You can get pretty good battery life on LED flashlights. For an un-powered speaker, a cell-phone reserve battery recharged as needed may do fine.

If you play LOUD: rectify and regulate the speaker signal. An LED is 0.03 Watts, speaker is 40 Watts? power drain should be insignificant. Done simple, it only lights when you play loud, but with more complication it could maintain a battery for break-time.

[jonyoungyi]

I bought these "step down" modules that take our high AC voltage and output 9v DC 500ma, etc.

On my Hoffman Blues Junior I wanted to add digital reverb. Basically, I had to put a pedal inside the amp, connected to the effects loop return. To get the 9v DC required by the pedal (Box of Hall reverb from culturejam), I took apart a 9v wall wart and just mounted that sucker sturdy and wired to my AC line coming into the amp.

I haven't used the "step down" modules I bought off eBay yet, but essentially it sounds the same thing as the wall wart method I mentioned above.

It's been a few months now and it's worked swell!