LED trick...again...(sorry)

[boxbuilder]

Hi all,
       I've just built this (http://www.boardsprep.com/mp3/BrianMayBoost.gif) and all is well....works as expected.
I'm using a DPDT switch so decided to try this (http://www.diystompboxes.com/analogalchemy/pedals/ledtrick.html)...and..all is NOT as well as expected!

The switch bypasses fine & dandy, but the LED doesn't turn off....at all. Doesn't even drop in brightness??

(Prototype build, at the moment the LED trick is on a separate board)

[D Wagner]

The best thing that I can recommend from experience, is to build a Millennium bypass, version 1 or 2.  I have built both of them, and have not had any problems.  Do not forget the 100k resistor to ground at the output of the effect, though.

http://www.geofex.com/Article_Folders/Millenium/millen.htm

[Fumi SG]

I should buy me a 3PDT switch, but that's just me! :wink:

[Samuel]

FWIW I have had precisely the same issues with the J. Davisson LED trick - I'm sure there are adjustments to be made to resolve it, but I just switched over to the Millenium circuit.

[slacker]

I've used the LED trick on a couple of pedals and it works fine. If you've built the circuit exactly as in the schematic it won't work though. For the LED trick or the millenium bypass to work the control line (the one connected to the switch) needs to have a path to ground, through a resistor or pot. To make it work you need to add a resistor after the output cap (E) connected to ground. A 100K should do it.
If you want to test that the LED trick is wired up right then just touch the control line to ground and it should go off, if not somethings wrong.

Hope this helps

[boxbuilder]

I've used the LED trick on a couple of pedals and it works fine. If you've built the circuit exactly as in the schematic it won't work though. For the LED trick or the millenium bypass to work the control line (the one connected to the switch) needs to have a path to ground, through a resistor or pot. To make it work you need to add a resistor after the output cap (E) connected to ground. A 100K should do it.
If you want to test that the LED trick is wired up right then just touch the control line to ground and it should go off, if not somethings wrong.

Hope this helps

Slacker!!...You're a legend....I can't try this 'till tomorrow, if it works then THANK YOU in advance.
Will the 100k affect the brightness of the LED when 'ON'?....Conversely, if the LED doesn't turn completely off should I increase or decrease the 100k resistor value??

Regards...Dave

[slacker]

Happy to help, this is probably the first time I've been able to offer any advice

No the 100K won't affect the brightness of the LED because when the LED is on it's not connected to the 100K resistor.

If the LED doesn't turn off completely you could lower the value of the 100kresistor but I wouldn't recommend it because if you go below 100K you'll probably start to change the sound of the pedal (in a bad way). What you can do is increase the value of the 330K resistor on the LED trick transistor.