Instructables

Distortion For Cheap!

Step 4: The Schematics

Picture of The Schematics
distortionswitches.bmp
Here is the schematic for the actual distortion. After is a schematic of how I wired the switches. If they are too small to read, here are links to larger ones:
http://i291.photobucket.com/albums/ll288/heyzuphowsitgoin/Distortion1.jpg
http://i291.photobucket.com/albums/ll288/heyzuphowsitgoin/distortionswitches.jpg

If you don't know how to read schematics, don't worry! Just pay attention to the notes on the images. You would be better off looking up how to read schematics, though, just to be safe.

Pay attention to the back of the LM741 package for the terminal numbers, if you get those wrong you could cook the amp. All the numbers on the schematic are right, just placement is funny, because the amp is a rectangle, while the schematic amp is a triangle. Don't ask my why... I didn't invent schematics.

When grounding, solder a stripped wire across most of the perf board, and when you ground something, just attach it to that. That will count as your ground, no need to solder it to the case!

NOTE: The second schematic is just how to wire the switches to the op amp, so you will still have to use the resistors from the first schematic. I made two different schematics because I knew people would want to use their own switch layout. This way they can see how the switches work.

For the 1/4" jacks, there should be two terminals coming off across from each other. If you look carefully, you can see that one is attached to the long contact while the other is attached to the entrance to the jack. Connect the one at the entrance to ground, and the other pin to where the schematic says (in=pin 2 out=pin 6)
 
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coolguy20153 years ago
Do we have to use 2 9v batteries??
No. He used 2 batteries because he needs to generate a negative voltage. A resistor divider works but the voltage is lower.
soyoso4 years ago
hey I'm not really sure how does the DPDT switch works, in one position you're sending the guitar input to the opamp, but in the other position are you sending the guitar's input to the opamp's output? I know it's a stupid question but I've never used that type of switch and was just wondering =P
its a bypass switch
mathieus4 years ago
 hey. i was wondering if its a hard thing to replace the batteries with a  9v adaptor?

thanks
heyzuphowsitgoin (author)  mathieus4 years ago
 never tried it, but I don't see why it wouldn't work...
juanh55 years ago
hi! thanks for this! could you please post the diagrams again? the links are dead and i ain't pro to see the second one here...
Mandela5 years ago
Thanks ! now i know the jack input problem but, when at the output, connect at the entrance or the pin ? (my instinct says at the entrance) :D
heyzuphowsitgoin (author)  Mandela5 years ago
Yes, ground is entrance... if I understand what you're saying. Think of it this way... guitar cords are mono. The tip has the signal, while everything from that little black line down is the ground. That means, ground anything touching the ground on the cord.
thanks for the reply then, now i only have one question... Where is the ground? Are the ground is positive side of the batteries ?