Buffer noise

[Seven64]

So i just built a 9v buffer to run at the beginning/end/middle of my pedal chain, and am trying to figure out if it is working or not.  I get lots of feedback when it is plugged in when going guitar>buffer>amp, but no noise at all without the buffer.  its a constant hum whenever the amp is on, and gets worse with both volume and the volume control on the guitar.  i built the following layout:

http://www.aronnelson.com/gallery/main.php/v/MarkMs-Gallery/album15/album76/amz_JFET_Buffer_LAYOUT.gif.html

This diagram is confusing with the orientation of C2.  the square box is connected to the JFET but the negative strip in the circle faces the output.

[Seven64]

am i correct in thinking that the current cannot flow into the negative side of the e cap and to face it towards the output?

[harmonic]

Negative side of the cap should be towards the out.

[stringsthings]

am i correct in thinking that the current cannot flow into the negative side of the e cap and to face it towards the output?

the negative side of C2 does face the output ... one thing C2 does is let your guitar signal ( AC ) pass, and prevent DC from going out of the circuit ...

... i just put this circuit on the breadboard and verified that it works ... when the circuit works, you'll hear your guitar signal without much volume change ... do you have a multimeter on hand? ... if so, here's the voltages that i measured :

Vdd ( 9 volt battery ):  9.33V

Vd: 9.33
Vs: 4.32
Vg: 4.44

...  its a constant hum whenever the amp is on, and gets worse with both volume and the volume control on the guitar.  ...

my first guess is a ground not connected somewhere .. but that's only a guess ...

[Seven64]

should i ground the jacks to the pcb?

voltages are:

Vdd = 9.70

Vd = 9.70

Vs = 4.15

Vg = 3.22

here is what mine looks like as of now.

[slacker]

should i ground the jacks to the pcb?

Yes, you need a connection between ground on the board or DC jack to the audio jacks. As your jacks and the case are metal you only need to ground one of the jacks, the other will then be connected through the case.

[Seven64]

got it.  i was wondering about that.  should have tried it with some alligator clips before posting this thread.  i need to resist the urge to work on pedals and stuff when i am drunk, as i always come on here for something pretty stupid.