Print PDF
Favorite
Email
Here's a little project that guitarists might appreciate. It's a booster/overdrive/distortion pedal, depending on how you configure it.
With a few electronic components and some basic knowledge of breadboarding and/or soldering, it should be a relatively simple build.
With a few electronic components and some basic knowledge of breadboarding and/or soldering, it should be a relatively simple build.
Remove these ads by
Signing UpStep 1A Brief Overview of FETs
A FET, or a field-effect transistor, is a transistor (funnily enough) that uses a variable electric field to control the electrical resistance of a semiconductor channel.
The type of FET we'll be using for this project is an N-channel JFET.
The channel in a JFET is somewhat like a garden hose - under normal conditions, water (current) flows through it at a rate determined by its area of cross section. The depletion region is like your hand. As you reverse bias the P-N junction (squeeze the hose), the depletion region grows wider (and the channel narrower), thereby increasing the channel's resistance. Then you hit a point where the depletion region has "pinched off" the channel, effectively making the JFET a large value resistor (around a couple of megaohms from drain to source).
Unlike a diode however, the P-N junction in a FET isn't capable of handling much current, and any forward biased (Vgs > 0) n-channel JFET will likely fail soon. (MOSFETs get around this by adding a thin layer of silicon dioxide at the junction, effectively disallowing current flow).
Okay, so let's get started.
The type of FET we'll be using for this project is an N-channel JFET.
The channel in a JFET is somewhat like a garden hose - under normal conditions, water (current) flows through it at a rate determined by its area of cross section. The depletion region is like your hand. As you reverse bias the P-N junction (squeeze the hose), the depletion region grows wider (and the channel narrower), thereby increasing the channel's resistance. Then you hit a point where the depletion region has "pinched off" the channel, effectively making the JFET a large value resistor (around a couple of megaohms from drain to source).
Unlike a diode however, the P-N junction in a FET isn't capable of handling much current, and any forward biased (Vgs > 0) n-channel JFET will likely fail soon. (MOSFETs get around this by adding a thin layer of silicon dioxide at the junction, effectively disallowing current flow).
Okay, so let's get started.
| « Previous Step | Download PDFView All Steps | Next Step » |
another thing, you mentioned using a stero input jack or putting a switch in, do you mean a stereo jack or do you mean an internally switched mono jack?
As for the tone control and 4-way selector, sure, I'll post a schematic in a bit.
It's useful to learn about tone controls in depth, though, since you'll be able to customize your tone to your preferences.
http://www.instructables.com/id/Make-a-Sweet-Portable-Guitar-Amp/
And i needed a switched panel mount 2.5mm dc power jack and i couldn't find any in the style i needed and i needed a normal 1/4" mono input jack in a panel mount style and i couldn't find one in the style i wanted but could find switched ones! Bit ironic. Now i realise that a switched input and switched headphone output would have been better than normal ones with a switch. I don't know why the author used a switch instead.
And yeah i agree trial and error can sometimes give the best results for you, but because i'm only a beginner i need a good baseline to start from, then i can try other things and if i don't like it i can revert back to the tried and tested one.