dl4 preset mod question?

[ppatchmods]

i have a question about this mod. if this is not appropriate, please delete this post. is this a spdt switch? if so, can the led be powered just like it's drawn or does it need to go to another power source? thanks

[ppatchmods]

this is a rough attempt to understand this. let me have it  

[Processaurus]

That's supposed to be a spdt switch.  It uses a 9v battery to light the LED, and a 2nd resistor to keep the LED from burning out (4.7K would be a good place to start, less= brighter, more= dimmer).  You got it pretty wrong 

It will work fine, but there's a way to do it without using a battery, and light the LED by power leeched off of the line 6 pedal, and just use a SPST switch, that Jeorge Tripps shared a while back.  I don't have a schematic, but use a mono jack, hook a (superbrite) red LED anode to the tip, then a 2K resistor to the LED's cathode, then the other end of that resistor to the sleeve on the jack.  Hook the one side of the SPST to the tip, and the other to the sleeve.  That's it!

When the switch is off, the Line 6 sees about 3 volts on the tip connection, and that lights the LED, and when you turn the switch on, it shorts out the LED and the Line 6 sees 0v on the tip connection, just like what happens at the two extremes of their expression pedal (which is a 10K variable resistor between the tip and sleeve)

[Derringer]

exactly what would that do for you sound wise?

which variable would you want to alter from full on to full off real quick like that?

thanks

[ppatchmods]

it basically takes the place of the exp pedal. it's just using the 10k resistor in place of the 10k pot. you can use it to have "double the presets"...but not really 

[thereverend]

i dont understand why this is a "double" presets mod since it doesnt double the presets. it just gives you 3 presets with 2 different settings for each.

[Processaurus]

It's being liberal with the truth to say it doubles the number of presets, it makes each preset have 2 variations, which is handy in a different way, like you can have a delay going into oscilation with the feedback and use this switch (or the real expression pedal) to morph the delay setting so the feedback lessens, I use that a lot, or on the rythmic delay setting, having one setting be half the time of the other, because the tap tempo affects both the toe up and toe down in that particular model, unlike if you changed presets.  Also if you hate how the tempo you tapped goes away when you bypass the delay, you could use the expression pedal substitute switch to turn the mix to 100% dry, and when you switch back, your tapped tempo is still there.

I stick the switch in the top of the modeler pedals (a forumite named pharaoh amps' idea), it's the bees knees.

some more on this idea, Mr Huges idea is actually a little different than I described above:
http://www.diystompboxes.com/smfforum/index.php?topic=33554.msg233549#msg233549
http://www.diystompboxes.com/DIYFiles/up/EX1Foot.PDF

[ppatchmods]

Processaurus, the second schematic i have also but it doesn't show the power source for the battery. is there a way to do it without the battery?

[silverrush540]

BUMP! I'm trying to figure out the same thing...I've asked on a couple of forums but I can't seem to get any help...the only thing google search returns is links to buy instructions...I dont know how to read wiring diagrams so I was hoping to find a simple explanation... Can anyone simply explain how to do the mod with an LED without the battery?

[sevenisthenumber]

bump...

[Processaurus]

Hi, Mr Huges schematic uses current coming out of the expression pedal jack to light the LED, no battery necessary.  I don't think there is enough voltage to turn on a blue or white LED.

This has come up a couple times, here is a slightly different schematic of how to make it with a SPST switch, like out of an old amp switcher, rather than the SPDT switch.



To the person asking how to wire this, the lines are wires, and the other 4 things are components.  The flat side on the physical red LED corresponds to the horizontal bar on the schematic symbol (the cathode).  The switch can be hooked up either way, all it does electrically is either connect two wires or not.

http://arts.ucsc.edu/EMS/Music/tech_background/schematics/ReadSchem.html

[ppatchmods]

thanks so much for the response. i was almost certain there was a way to do it but didn't know how. thanks again

[silverrush540]

Thanks so much...I'm going to try it now!

[silverrush540]

Hi, Mr Huges schematic uses current coming out of the expression pedal jack to light the LED, no battery necessary.  I don't think there is enough voltage to turn on a blue or white LED.

This has come up a couple times, here is a slightly different schematic of how to make it with a SPST switch, like out of an old amp switcher, rather than the SPDT switch.



To the person asking how to wire this, the lines are wires, and the other 4 things are components.  The flat side on the physical red LED corresponds to the horizontal bar on the schematic symbol (the cathode).  The switch can be hooked up either way, all it does electrically is either connect two wires or not.

http://arts.ucsc.edu/EMS/Music/tech_background/schematics/ReadSchem.html

Are you using a 3mm or 5mm LED? All I have on hand is a 5mm LED that I took out of a broken Morley Wah pedal. I can't seem to get the LED to light.

[ppatchmods]

it probably has to be a low voltage led...so a 3mm would be your safest bet

[Processaurus]

The size of package doesn't matter (ha ha), the color is what matters, electrically, as far as meeting the turn on voltage.  If the wiring is good, maybe try your LED the other way, or a different LED. 

[silverrush540]

The size of package doesn't matter (ha ha), the color is what matters, electrically, as far as meeting the turn on voltage.  If the wiring is good, maybe try your LED the other way, or a different LED. 

I'm going to try and look for a lower voltage LED at radio shack tomorrow because I think this needs too much...even though the LED doesnt work the switch works! 

[Processaurus]

Oh, sorry, didn't explain that well, there's no such thing as a low voltage LED, all of the red and green ones take about 1.4v to turn them on and start conducting.  Blue and white ones have a forward voltage of about twice that, like in keychain flashlights the white and blue ones need a 3v lithium battery to make them light up.  The red and green ones can work off of a 1.5v alkaline battery.

Your LED may be broken, too much heat can fry them.   The circuit will work the expression pedal input fine without the LED in it, if you want to make sure the rest of your wiring is right.

[ppatchmods]

anyone know where the lugs of the exp jack on the dl4 go? it's kinda hard to trace the board to see sleeve and tip. it is a regular mxr/crybaby style enclosed jack. thanks

[Processaurus]

stick a plug in there to tell the difference between the 3 normaled contacts and the others and beep it.  That's the only way to do double sided boards that have traces going under the parts.  I believe it basically goes down to the closest SMTchip by it for ADC.