I need help building a 4 button footswitch

Discussion in 'Shock Brother's DIY Amps' started by FelixV, Mar 20, 2020.

  1. FelixV

    FelixV TDPRI Member

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    I would like to build the footswitch shown in this schematic https://www.thetubestore.com/lib/thetub ... ematic.pdf


    I don't have any experience at all with something like this and i would like some guidance please.

    I presume that the unmarked diodes are 1N4448 as indicated in the text, but what voltage, current and wattage rating would they be?

    Are the footswitches latching or momentary? on/off or on/on?

    What voltage LEDs would I need to use and do they have to be red?

    The socket symbol is unknown to me, I am confused by the arrow pointing at the socket tip, is this a TRS stereo socket? What does the arrow symbolise?

    Is the socket sleeve ground?

    Are there any components not pictured e.g resistors for leds?

    What kind of cable would I use to connect this to my amp?

    Is there anything else you think I should know?


    I think this should be a relatively simple build but I am a total beginner at stuff like this so excuse my lack of knowledge. I hope I haven't overwhelmed you all with my questions!

    Thanks
     
  2. wabashslim

    wabashslim Tele-Afflicted

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    I presume that the unmarked diodes are 1N4448 as indicated in the text, but what voltage, current and wattage rating would they be?

    Diodes of a given part# have a fixed rating, so just shop for that part#.

    Are the footswitches latching or momentary? on/off

    What voltage LEDs would I need to use and do they have to be red?

    Just get red ones, they'll likely be around 1.2v - 1.4v. ?????

    The socket symbol is unknown to me

    Just a regular mono jack for use with an ordinary speaker or guitar cord. That's what all that voltage-control circuitry is for, to make the hookup simple.

    Is the socket sleeve ground?
    Yes

    Are there any components not pictured e.g resistors for leds?
    No

    Is there anything else you think I should know?

    Soldering, heat-sinking, component orientation, how to play...

    I think this should be a relatively simple build but I am a total beginner at stuff like this so excuse my lack of knowledge.

    Gotta start somewhere, and this is as good a project as any. Good luck!!
     
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  3. Splodgeness

    Splodgeness Tele-Meister

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    Red LEDs have a forward voltage drop of around 2.2v. Yellow and orange LEDs are slightly higher at around 2.6v Other colours (including white) are around 3.3v.

    Red LEDs are specified but you could possibly use yellow or orange. (I'd just go with red to be closest to the original design)
     
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  4. FelixV

    FelixV TDPRI Member

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    Thanks a bunch guys, you've really helped me out.

    The switch is the only thing i am unsure of now, the schematic shows a SPDT but i'm not sure if its momentary or latching and if its normally open or normally closed type? Can't SPDT be wired for either? Why not use a SPST if the third lug isn't connected to anything? (not even ground?? :confused:)
     
  5. Peegoo

    Peegoo Tele-Afflicted

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    They are latching. Unless the schematic shows that specific symbol (looks like a doorway on a floor plan) and includes a note identifying it as "momentary," it's a latching type.

    This is the symbology for a momentary switch:

    [​IMG]
     
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  6. FelixV

    FelixV TDPRI Member

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    I guess SPDT are used because I haven't been able to find any latching SPST footswitches for sale anywhere...
     
  7. FelixV

    FelixV TDPRI Member

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    I just want to check if this is all correct,

    Here is my layout,
    [​IMG]

    The switches are labeled by their first letter.

    Lug 2 on every switch is not connected to anything.

    4 Red LEDs
    4 SPDT Latching Footwitches
    4 1N4448 Diodes
    2 15223B Diodes
    1 Mono 1/4" Socket

    I'm going to use a 1590BB enclosure.
    Connected to the amp with a standard 1/4" mono instrument cable.
     
  8. FelixV

    FelixV TDPRI Member

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    Sleeve is incorrectly labelled "ring".
     
  9. wabashslim

    wabashslim Tele-Afflicted

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    They should be common as dirt. Maybe the problem is...
    "latching" to most techs usually refers to a circuit that once turned on, keeps itself turned on via a relay or whatever, usually using a momentary switch. What you want is more commonly called an "on-off" switch, at least in this country. At least with a SPST. Still, most people should know what you're talking about. And usually that's just called a "switch"; a "momentary" is an added specification. At least in this country. I guess...
     
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  10. FelixV

    FelixV TDPRI Member

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    interesting, thanks
     
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