can you put a led in the electric mistress clone from GGG?

[marrstians]

can you put a led in the electric mistress clone from GGG? i tried hooking it up to the power in the pedal but it grounds out the signal so nothing comes through... i'm not sure what else to do but have a seperate 9volt batery in there...  can i hook up a led to ac power or something so i doesn't hit the circuit?.

[Travis]

You should be able to power the LED from the output of the 7815, with resistor adjusted for 15V, of course.

[marrstians]

tried that... it doesn't work... it grounds out the signal... i ever tried putting a seperate 15v regulator so it was different from the power of the effect and that grounded the signal out too... i'm stumped...

[SoundTech]

Just out of curiosity, what value resistor were you using?

[marrstians]

i tried a bunch of different ones... every where from 3k to 3m...  even with 15volts it wouldn't light up with too high a value... if i connectecd the led stright up to the 15volts it worked fine and didn't ever burn up the resistor so i don't know what's going on...

[Travis]

Does the LED work?

[SoundTech]

Somewhere around 1.5k to 3k should work fine as the current limiting resistor in line with a regular LED.  So, the pedal works just fine until you add a resistor/LED across your voltage regulator??

[marrstians]

yeah... the led will work fine, light up and switch on and off with my 3pdt switch but when it's connected to the circuit it grounds out the signal... very odd... i've never had this problem before...

[Travis]

How much current does your transformer provide?

[marrstians]

around 24volts ac power...

[Travis]

Well, you may just want to work around it.  Try picking up a "grain-of-wheat" lamp.  Hook it across the AC power.  

How many amps does the transformer supply?

Are you in the US?

[marrstians]

i'm not sure the amps... i'm guessing 1.5... it's from a deluxe memory man... what's a grain of wheat?

[SoundTech]

So, the pedal works fine all by itself with no LED, and the LED/resistor works fine all by itself with no pedal, but put them together, and no audio, eh?  I can't help but ask, are you absolutely sure everything is hooked up properly?  With the right resistor, the LED will only draw an extra 5-10 milliamps, which isn't enough to kill power to the circuit.  Do you have a multimeter?  Measure the voltage at the output of your voltage regulator.  Hook up the resistor/LED again, and measure the voltage at the output of your regulator.  Have you tried a different LED?

[marrstians]

i've tried a couple of different leds... i don't know if it's the current draw that's the problem because even without any resistor and just the led in the circuit it does the same thing

[SoundTech]

Well, if you put in JUST the LED with NO current limiting resistor in series with it, then you essentially short circuit the power supply!  The v-reg is probably going into protect mode when you do this, but I'm surprised the LED didn't get burned out.  Usually doesn't take to long to blow those.  So, again, take a fresh, unused LED, and a, say, 3K-4K resistor or so, connect one side of the resistor to the output of the v-reg, connect the other side of the resistor to the positive side of the LED, and connect the negative side of the LED to DC ground.  Again, if you have a meter, measure the voltage before and after you connect the LED, and see what your v-reg is outputting in both cases.  Also, if you HAVE shorted the output of the regulator, it might be time to replace it.