Isolate ground (LED and switch)

[Plexi]

Hi forum..!
Happy Easter!

I'm finishing my super Box of Rock, with a 3 ways internal switch to select 3 "high gain" modes options (Distortron switch).
Mode 1: high gain (link 3rd Mosfet S to ground = maximum gain).
Mode 2: normal BoR
Mode 3: the Distortron side works as normal, but when engage the SHO side, it switch the high gain mode.

That part was easy... the trouble comes when I install the LED in the same switch that can "link" ground in the Mode 3.


The led keep turned on all the time.

Any diode between the led and the 2k2 resistor could work? electrolitic cap?
Any advise?

Thanks!

[Plexi]

[EBK]

I don't know what the rest of the corcuit looks like, but maybe you could increase that 2k2 resistor until the LED no longer lights up?

[Plexi]

I don't know what the rest of the corcuit looks like, but maybe you could increase that 2k2 resistor until the LED no longer lights up?

I've tried, but it only reduce the brightness.
Tried the diode, and didn't work.

[Plexi]

To clarify: the main problem is that the Led is linked at ground with the red path.
The idea, is to "direct" that path in the green way.

I've tried a 10uF cap between 330 and 2K2 resistor, and it seems to work.
Which is the theoric reason?

[antonis]

Theoretical reason can be found by wondering yourself about the reason made you to place that cap/resistor.. 
(thinl what you've thought for doing that..)

(although it seems to me like just an LED anti-pop arrangement rip off..)

[Plexi]

Theoretical reason can be found by wondering yourself about the reason made you to place that cap/resistor.. 
(thinl what you've thought for doing that..)

(although it seems to me like just an LED anti-pop arrangement rip off..)

Empirical method, try several things, or just copy a bit the Fuzz Face fuzz pot schematic?

[GibsonGM]

Why don't you make it easy on yourself and take out the single pole switch....use a DPDT to totally isolate the LED and the ground on the right side from each other?

Switched to LED mode, ground is 'not there'.   Grounded mode... LED is not there.   That's what I'd try, at least on paper.

[Plexi]

Why don't you make it easy on yourself and take out the single pole switch....use a DPDT to totally isolate the LED and the ground on the right side from each other?

Switched to LED mode, ground is 'not there'.   Grounded mode... LED is not there.   That's what I'd try, at least on paper.

Because that single pole switch in the schematic, is the middle side from a 3PDT footswitch. It only activate the Led on when the SHO is on, and before it, is the 3 way switch I've mentioned.

[Plexi]

Complete schematic:


From top to bottom:
Mode 1: Normal BoR (low gain)
Mode 2: the Distortron side works as normal, but when engage the SHO side (3PDT), it switch the high gain mode.
Mode 3: high gain (link 3rd Mosfet S to ground = maximum gain).

[GibsonGM]

I have no clue how you would solve this, as there are (of course!) two low-resistance paths to ground with what you want to do!  Switching is a pain in the @ss.     

If the LED is simply an indicator (maybe I am not following you correctly, if so, sorry!), perhaps there is a way to use the Millennium Bypass (R.G. Keene) in some way, to 'tap off' from some point to do what you want?

OR, 4PDT.....

[Plexi]

I have no clue how you would solve this, as there are (of course!) two low-resistance paths to ground with what you want to do!  Switching is a pain in the @ss.     

If the LED is simply an indicator (maybe I am not following you correctly, if so, sorry!), perhaps there is a way to use the Millennium Bypass (R.G. Keene) in some way, to 'tap off' from some point to do what you want?

OR, 4PDT.....

At the moment, as I've mentioned, the solution was a 10uF cap between 330 and 2K2 resistor, and it seems to work.
Which is the theoric reason? I don't have a clue...