I'm smokin' LEDs

[jeff g]

2 so far, on an easy build - The BigMan's Passive ABY Switcher
this is my 3rd botched build in a row, and I picked it as an easy one !!

the details:

I used this layout     http://aronnelson.com/gallery/TheBigMan-Layouts/abyled

Substituted a metal switching DC jack for the battery


When I power it up, there's no sound on bypass or engaged

Neither A or B LED lights up

The A/B LED lights at two different intensities then smokes

I think the switches are wired correctly, but I guess I've got a problem at either the input jack or the DC jack.  I've wired them like this:

Input - Tip to left switch, top row middle lug (should this go to ring?)
        - ring to DC jack large lug

DC jack - oriented so lugs are horizontal, with large lug on left

large lug - Input jack Tip
 
Top lug - LED cluster

Right lug - nothing


Where did I go wrong?

[Seljer]

are you sure you used 1k resistors? if you did, try something larger than 1k and check for any shorts

LEDs shouldn't burn out unless you connect them directly the 9v and ground with nothing else to limit the current in between


edit: also, there should be sound even if the LEDs didn't work. are you sure you didnt get the 3DPT switch turned around for 90°? the solder lugs should be wider horizontally, looking at the way its set up on that diagram

[Noplasticrobots]

Oh, but blowing up LEDs is so much fun! 

[jonathan perez]

blue LEDs on a fresh 9volt burn the best, and smell the worst.

[jeff g]

     LEDs shouldn't burn out unless you connect them directly the 9v and ground with nothing   
     else to limit the current in between

oops - I forgot a 1k resistor for the AB LED (how many times did I look at that layout and not see that !!)


     edit: also, there should be sound even if the LEDs didn't work. are you sure you didnt get   
    the 3DPT switch turned around for 90°? the solder lugs should be wider horizontally, looking   
    at the way its set up on that diagram

oops again - for some reason, I oriented the switches the other way, even though I should know by now

thanks Seljer - nice troubleshooting


anyways, how does it work you might ask?

great - I'm using it to switch between 2 amps, and there is very little hum with no effects inbetween

but, at the end of my pedal chain it sounds like s%*t !   No actually it sounds more like a green ringer that's sort of working, really farty / buzzy and quick to decay.  This may be a function of too many crappy cords between pedals, I'll try again later

for now I'm happy with it (and I may not have to build a more complicated transformer based splitter)

by the way, how the hell do you insert quotes?  when I try, all I get is the text, not the highlighted window that others put in their messages

[jonathan perez]

where it says insert quote, up on the top right hand corner of whatever has been posted...

preview before you post, to see it work.

[choklitlove]

am i missing something?  aren't the resistors supposed to be between the +9V and the led, not ground and the led?  the leds look like they're facing the correct direction, just the resistors should move...

[mdh]

am i missing something?  aren't the resistors supposed to be between the +9V and the led, not ground and the led?  the leds look like they're facing the correct direction, just the resistors should move...

It doesn't matter whether a current limiting resistor is between V+ and the LED or the LED and ground, it just needs to be in series with the LED, and of the appropriate value to limit the current going through the LED. There's probably a wiring problem, but I don't think it's the fault of the layout.

[choklitlove]

am i missing something?  aren't the resistors supposed to be between the +9V and the led, not ground and the led?  the leds look like they're facing the correct direction, just the resistors should move...

It doesn't matter whether a current limiting resistor is between V+ and the LED or the LED and ground, it just needs to be in series with the LED, and of the appropriate value to limit the current going through the LED. There's probably a wiring problem, but I don't think it's the fault of the layout.

my bad, i just don't think i've ever seen it done that way before.  well, i learned something today!

[Funky_Tomo]

Would it not be easier to..

A) have one LED for A and one LED for B with a 330ohm resistor? To make it brighter.
B) have Those two LEDs go on when they are both on.....

Just checking, i might make one.