LED Indicator Light (stupid mistake calls for stupid question)

[hesamadman]

Laid out my chassis in photoshop. Printed it out and realized "hey I have my input and power switch on wrong side. So I edited the drawing and put them in the correct place, however I forgot to move my LED indicator location. I didnt realize this until after my chassis was drilled. So right now my LED is in about a 2 inch space between my preamp volume and my input.


Question is, with the LED rectifying that current, could it still interfere with my input being somewhat close?

[terminalgs]

If you have to run the 6.3V filament supply to it, you certainly could arrange the wires in a way that would cause the input to pick up noise (for example, if you have to run the wires under the input jack).


another option is to get your LED voltage from B+.  You could put the LED in series with a plate resistor, or under a cathode resistor.  The problem with this would be if you are using a tube rectifier, your indicator lamp won't light up until the rectifier tube has warmed up and B+ is flowing.  "Is this thing on or not?!?"

[kagliostro]

A resistor with an in series diode connected to the 6.3v will be a good supply for a LED

also only a resistor may be enough, the LED is a diode, so it rectify by himself the voltage for his function

K

[hesamadman]

If you have to run the 6.3V filament supply to it, you certainly could arrange the wires in a way that would cause the input to pick up noise (for example, if you have to run the wires under the input jack).


another option is to get your LED voltage from B+.  You could put the LED in series with a plate resistor, or under a cathode resistor.  The problem with this would be if you are using a tube rectifier, your indicator lamp won't light up until the rectifier tube has warmed up and B+ is flowing.  "Is this thing on or not?!?"

Yea it actually wouldnt come on at all until stand by is flipped also so I couldnt do that. I could most definitely rout it so that its not under my input jack, however it may mean that I will have to go under the preamp volume. I have a deep chassis. It wouldnt be close by any means......but how close is too close. My only option may be to see what happens but I hate that.

[HotBluePlates]

What if you just left the existing hole unfilled, and drilled a new LED hole on the side of the chassis where you wanted to have it?

Welcome to the joys of amp building! Everyone has made mistakes like this. Then each had to make the choice of whether to whether to start over from scratch, accept a cosmetic defect for better operation, or roll with a mistake and possibly compound it.

When I started out, I tried to force the mistake to work, which usually didn't turn out well. Now, I just accept the cosmetic defect instead of starting over. Every time, I've learned about something I overlooked, which improved subsequent builds.


Alternatively, you could try using the LED where it is. Original Standel amps had a light-up faceplate by having a 6.3vac pilot light at each end of the faceplate, putting one close to the input jack. Apparently, they didn't run into hum problems, and you might not either.

The question is whether you have an exit-strategy if you find you get hum/interference. Do you need a pilot light? Are you willing to leave the empty hole if you have to yank out the LED near the input jack? Will you then want to relocate that LED?

If you think you will still want the LED if it doesn't work in the present location, you may want to drill the better location now. It's always easier to drill an empty, incomplete chassis.

So you'll have to think through the "What If" and decide what works for you. And maybe you'll get lucky with what you have now.

[sluckey]

I'd try it as is first. There 'may' not be any hum issues. But if there are issues, just use a diode/cap/resistor located near the PT to convert your AC supply to DC. Send the DC wires to the LED and no worry.

[hesamadman]

What if you just left the existing hole unfilled, and drilled a new LED hole on the side of the chassis where you wanted to have it?

Im A dummy because I jumped the gun and drilled the holes to accommodate the art work that goes on the faceplate. So moving it would clash with it all 


Worse case, I will eliminate it. I also thought about running the leads for the LED on the outside of chassis and drilling a hole right under the LED for the leads to enter. I would rather not do this but if I get hum....this is what I will do. I have a sleeve of a sort of conduit I will put the leads in outside the chassis.

[hesamadman]

I'd try it as is first. There 'may' not be any hum issues. But if there are issues, just use a diode/cap/resistor located near the PT to convert your AC supply to DC. Send the DC wires to the LED and no worry.

Ahhh,,,,,,perfect sluckey thanks.

[kagliostro]

I missed to ask if you drilled the chassis and the faceplate or only the chassis

if you drilled only the chassis one other way will be to use a faceplate to cover the hole

K