SmashDrive isn't smashing... (no dist)

[jtkiv]

to begin, this is my first pedal, first electrical project and first post here  

determined to build not buy, i set out to find a simple distortion box project.  i found www.runoffgroove.com, saw that the design for the "grace / big daddy" was very simple, bought the parts, put it together on a breadboard - no sound.  messed with it for a while then decided to research the IC 386 to ensure that i was using it correctly.  after some digging found that the "grace / big daddy" was based on/linked to the "smashdrive" box by aron nelson.  

put the smashdrive together using this:



after using some parts i bought for the "grace / big daddy" and some others that were laying around, i have this:



and the result is a clean, undistorted sound (i am happy to have sound though!)

i know that many of the parts are kinda far from the prescribed ones, but i wouldn't think they're far enough away to remove all distortion.   if anyone could help, it'd be much appreciated (p.s. im leaving for 1 & 1/2 weeks of vacation on friday so i'll check back before and after i leave)

thanks (and sorry for large images)

[jtkiv]

reading around on the forum, i noticed a post that said a larger capacitor produced more gain, that made me think that maybe one of mine is too small... then i realized after the drive pot and the 100ohm resistor there is a 47uf capacitor, in my circuit i have a .1uf...  perhaps this is the problem?

thats the biggest capacitor i have currently, i can buy another (no problem), but i'd like to know if its going to produce the distortion before i buy it...

[phector2004]

have you tried putting in a 10uf electrolytic cap (where marked as "bypass")?

[jtkiv]

cleaning up i found a 100uf capacitor and put that in the 47uf spot, still clean

phector2004 - forgot that in my drawing (sorry) but i have tried various capacitors in that spot and still nothing 

[phector2004]

i know this is gonna sound dumb/obvious, have you played with the knobs? I spent a whole hour debugging an unusually "tame" pedal once and it turns out I had wired the pot backwards    "Full" gain was actually no gain

I don't see anything wrong with your schematic. If you still don't see any difference, you can mess with the clean tone by adding other things to the circuit. A simple idea is to add clipping diodes - stick two diodes in after the .1uF film output capacitor connected to ground, facing different directions:

----||--------------- OUT
          |       |
          ^      v
          |       |
------------------- GROUND

(Hope that comes out right!)

Another thing to note, capacitors are mostly used for filtering the signal, etc. They let AC current through (think guitar signal).
Resistors are what I would play with if I were you

[deadastronaut]

hi heres what it should look like (vero version.). i did this earlier today for ya to look at...



hope it makes more sense than looking underneath etc.....

another mod i messed around with was putting a 10uf from pin 1 ground too..lots of distortion..

might need another 100r just after it too though to stop it squeeling...

but in general i found a 10uf from pin 1 to pin 8 gets quite dirty...as long as they are not connected together already..

i meesed around with many variations on the 386..its a very good op amp for distortions...


p.s your pots will work backwards..so turn them ok

rob.

here is what it should look like on your breadboard!....

[jtkiv]

thanks for the diagrams!

after staring at the thing for half an hour i thought that perhaps my breadboard had some sort of fancy layout inside... so i checked various connections on the breadboard and found that it was in fact different than the diagram i had that showed what was connected.  (sorry if thats really confusing)

anyhow, after figuring that out i managed to get distortion    so now ive been playing around with the "smashdrive" and "grace / big daddy" layouts and implementing some of my own ridiculous ideas.  getting a very wide variety of sounds, so i'll just keep playing with it 'till i find the one i like!

thanks for all the help 

p.s. when the distortion came through i laughed a terribly evil laugh 

[deadastronaut]

great....glad to hear you got it working...