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wiring help

Discussion in 'Amps and Cabs [BG]' started by dr_love2112, Jul 21, 2005.


  1. dr_love2112

    dr_love2112

    May 28, 2005
    baytown texas
    i need help with making this a/b/y switch pedal for my amps and can some one explain the diagram.

    im using this to rum 2 amps at the same time.

    why do i need the resistors????
    where do i ground at???
    does amy body else know how to run a bass into 2 amps

    wiring diagram
     
  2. Petebass

    Petebass

    Dec 22, 2002
    QLD Australia
    Ignor that wiring diagram. That represents the inside of the ABY box.

    It should be a matter of plugging your bass into the input, and setting the device into "Y" mode. One of the outputs goes to amp1, and the other output goes to amp2.
     
  3. I think he means he's actually going to construct the A/B/Y box himself, instead of buying one.

    The resistors are probably there to help control the "thump" you might get switching from one side to the other. I didn't put any resistors in mine (and I didn't make it a "Y" box either) but the way I'm using it (to switch between two guitars) I can turn the volume down downstream with another pedal, so I don't have to worry about the thump.

    I'd put the resistor directly on each jack, from the "shield" terminal to the "tip" terminal. Doesn't need to be a big resistor, 1/4 or maybe even 1/8 watt ought to be plenty.

    Note that for this schematic to work, you need the fancy switched 3 conductor jacks for J1 & J3. J2 can be a regular cheap 2 conductor jack.

    Also note that both footswitches need to be DPDT for the LED's to be lit properly.
     
  4. dr_love2112

    dr_love2112

    May 28, 2005
    baytown texas
    well i really dont want the leds but how do i ground the box???? would i just connect all the grounds together.
     
  5. Petebass

    Petebass

    Dec 22, 2002
    QLD Australia
    Oops, looks Pete's been posting before he's had his coffee. Sorry guys!
     
  6. I think you can get away with the normal 2 conductor jack for J2 and J1. Just J3 uses the fancy switched jack to control the power. If you dump the LED's, you don't need power, then you don't even need J3 to be switched.

    Agreed, the resistors are for thump, and maybe to prevent the dreaded open circuit (buzz) when guitar isn't plugged in?

    The other resistors by the leds are just to keep the current to corrrect levels.

    Randy
     
  7. dr_love2112

    dr_love2112

    May 28, 2005
    baytown texas
    well pete i any manly going to be using it for that. but i would like it in a box instead a "y cable". and also with the box if i wanted 3 amps at once i could just add another jack. so im not gonna use no kind of switching
     
  8. If you don't want LED's all 3 jacks can be simple 2-conductor, and leave out the resistors, and then the switches are SPDT instead.

    Ground all the grounds together at one spot: take a ground wire from J1 and a ground wire from J3 (the "shield" terminal) and run them to the "shield" terminal of J2, that's all that's needed.

    Yes, the resistors by the LED's are just dropping resistors to supply the proper current/voltage to the LED's.

    Personally I'd say, if you're going to this much trouble to make a switching box, go ahead and get the DPDT switches and take a few more minutes to put the LED's in. It's kinda nice to know which side is active--for example I use my bos to switch between acoustic and electric guitars, i've only got a couple of seconds between songs sometimes, things get hectic on stage,and without the LED's I wouldn't know immediately which one was hot.

    For the LED's, the one change I'd make: I'd make J2 the 3-conductor jack (instead of J3)...this is always the "common" jack.


    edited: I re-read your posts, do I understand that you aren't even going to be doing any switching, you just want a box with 3 jacks in parallel?

    Run a ground wire from shield of J1 to shield of J2 and another from shield of J3 to shield of J2. Run the hot wire from tip of J1 to tip of J2 and another from the tip of J3 to tip of J2. You're done. No switches, no LED's, no resistors. 3 jacks, a few short pieces of wire.