FET Preamp (low gain), need a bit of help

[Don M Gard]

Can anyone help me make sense of this schematic.  I am not accustomed to dealing with circuits involving audio components.  Can someone answer a few questions for me?



FET Preamp Parts List:

Q1 J201 N-channel JFET
R1 3.0M ohm 1/4-watt 5% resistor
R2 2.2K ohm 1/4-watt 5% resistor
R3 6.8K ohm 1/4-watt 5% resistor
R4 51K ohm 1/4-watt 5% resistor
C1 4.7 uF electrolytic capacitor
C2 10 uF electrolytic or tantalum capacitor

http://www.till.com/articles/GuitarPreamp/

This is the schematic I have.  My questions:

How do I connect the 1/4" audio jacks?

Do I solder them both as above where it says 'signal input' and 'output', or do I solder them as below?


Where do I connect the 'signal ground' and 'ground'?
How do I connect the battery?  I'm really having a hard time with this one.  It doesn't seem to make sense to me.
Is there a certain direction in which I have to place the FET?

[markm]

Your Jacks in the bottom picture are fine.
Where it says  +9volts on the schem is + of the battery.
The JFET pins for the average J201 are G-S-D looking DOWN at the device with the pins down and the
Flat to the right.
D will connect to the 4.7uf
S will connect to the 2.2K resistor to ground
G is the input.

[Don M Gard]

Where do I connect the negative (-) terminal of the battery?  That is my biggest problem reading this circuit.  Once I have that figured out, I think I can start laying out my plans for how I'm going to put it on a PCB and in a little plastic box I have.

[markm]

Wait a minute,
It's hard for me to tell from the drawing but the Jacks seem to be wired backwards in the bottom drawing.

[markm]

Where do I connect the negative (-) terminal of the battery?  That is my biggest problem reading this circuit.  Once I have that figured out, I think I can start laying out my plans for how I'm going to put it on a PCB and in a little plastic box I have.

To test the circuit, the Negative of the battery can be attached to ground but, if you're going to be using a switch,
there's a bit more wiring involved.

[Don M Gard]

Wait a minute,
It's hard for me to tell from the drawing but the Jacks seem to be wired backwards in the bottom drawing.

The tip of the 1/4" plug goes to the input and the shaft of the 1/4" plug goes to the ground.  Is this correct?



As long as this is right, I know how to solder the jack.  If it is wrong, then I will have to solder it the other way.  The drawing is rather ambiguous, but I know which solder points correspond to which part of the jack.

To test the circuit, the Negative of the battery can be attached to ground but, if you're going to be using a switch,
there's a bit more wiring involved.

Do you mean the 'ground' or 'signal ground'? By wiring the negative terminal of the battery to the ground, will I have to unplug the battery in order to shut it off, or will plugging in/out a jack turn it on/off? 

I would rather my device have an on/off switch as well as a bypass.  I think I know how to make a bypass, but I'm really confused with the battery in the circuit on how to make an on/off switch.  Could someone help me with these?

[Don M Gard]

Bump

[markm]

Your Jack picture is correct.
The signal ground and ground are the same.....ground.
There are various switches and wiring that could be used as On/Off.
Traditionally, most effects use a stomp switch.

[Don M Gard]

I'm not actually making a stompbox.  It will clip to my guitar strap.  What kind of switch would I need? Anything special?

[Don M Gard]

This is my finished version.  Does this look correct?



I'm still not sure if I want to use a Power Indicator LED, I know they sap battery like no other.  I do want a bypass LED, though ... or do I?

[Don M Gard]

Another question: 
Instead of using 2 standard 1/4" jacks, could I use 1 mono jack and 1 stereo jack like the one I have circled in the picture?

This way, I save some space inside my box by running the wires to outside jacks.

[Don M Gard]

Bump

[Don M Gard]

Can anyone give me any advice?