dc jack porblems

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dc jack porblems

Postby copachino » 26 Feb 2014, 18:43

Hi, im building my first stompbox, its a bazz fuzz, i have addded the power suply filtering and polarity inversion protection, the problem i have its that when i try the pedal i get voltajes, as the led turns on, i check with my tester voltages and there its voltage going on, but the pedal doesnt work, if i unplug the dc jack and put a 9v battery the pedal works pretty fine, now i have find something that could be a problem but i dont know why its happens, when i meassure the voltage acrooss the drain resistor with the dc jack i get the same as power supply, but with the battery i get 1.30v, and the pedals works fine...

so why does the resistor do nothing when its running on dc transformer sup, and its works fine on battery..


also there its another problem, i cant get battery and dc jack working the same, i got connected gound to the ring of input, battery ground to slevee an input to tip...
i guess that the normal TRS config, but the problem its that under dc jack voltaje when i plug the input, its makes a short with the battery ground, simple, i just take off the ground wire in the input and then the dc jack worked "fine" but..... the battery doesnt work because it doesnt connect the ground of the battery with the ground of the circuit....


i dont know what happens here... i need help
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Re: dc jack porblems

Postby Govmnt_Lacky » 26 Feb 2014, 19:35

Image

Make sure that:

#1 is going to your Input jack SLEEVE (and is connected to your Output jack sleeve, PCB ground, and to the 3PDT for the LED ground) dont know where you put your limiting resistor.
#2 is going to the Battery clip POSITIVE
#3 is going to your PCB POSITIVE voltage input

Also, make sure that the Battery clip GROUND is going to the Input jack RING.
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Re: dc jack porblems

Postby copachino » 26 Feb 2014, 19:52

i got it connected that way, and i gel voltages on the pck with the jack, but the resistor of my drain its not doing a propper funtion with the jack, also if the battery goes to the input jack ring it create someting like a short with the battery ground, and the voltage goes down... im not sure what happens
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Re: dc jack porblems

Postby Govmnt_Lacky » 26 Feb 2014, 21:58

Pictures? Good, clean pictures are worth 1000 words!
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Re: dc jack porblems

Postby copachino » 26 Feb 2014, 22:57

im not at home right now, but do you think it could be that im using a metal DC jack???

Image
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Re: dc jack porblems

Postby copachino » 27 Feb 2014, 22:38

Govmnt_Lacky wrote:[ Image ]

Make sure that:

#1 is going to your Input jack SLEEVE (and is connected to your Output jack sleeve, PCB ground, and to the 3PDT for the LED ground) dont know where you put your limiting resistor.
#2 is going to the Battery clip POSITIVE
#3 is going to your PCB POSITIVE voltage input

Also, make sure that the Battery clip GROUND is going to the Input jack RING.



i have re-wiring the pedal with this jack, and i get voltages across the pedal, the problem its that the pedal doesnt work with DC transformer, only work when the battery its plugged, also one more thing, when i connect something to the dc Jack, the battery stop working even if the its no power on the jack, a guess its a normal swtching jack stuff
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Re: dc jack porblems

Postby induction » 27 Feb 2014, 23:41

copachino wrote:im not at home right now, but do you think it could be that im using a metal DC jack???

[ Image ]


Yes. That dc jack will put 9V on the enclosure, which is attached to your signal ground. This is probably the source of your problem. You need an isolated dc jack.
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Re: dc jack porblems

Postby copachino » 28 Feb 2014, 00:21

i got intalled and isolated jack, i will try later i comment if that worked
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Re: dc jack porblems

Postby copachino » 28 Feb 2014, 04:00

yep, it worked pretty fine with the plastic DC jack... thanks all for you help
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