i know the circuit board works, but now that i have everything wired together and in the box, something is wrong. when i turn the fuzz nob all the way to the left and the volume to the right, a very weak signal comes threw. it's hard to tell if it's a good fuzz. the pots i have are 500k alpha for volume and 1k for fuzz. any suggestions?
thanks for any answers.
First, I'd check that the board, the input and output and the volume pot all have good earths (easy to check with a meter). Does it work ok with the pots at half way? Could you give a clearer explanation of what (if any) sound you are getting?
cheers
How did you know it worked? Did everything work out of the box? If so, then maybe you have a short somewhere when you put it into the box or you might have a bad solder/wiring connection.
You might want to take it out again, verify that it works, then put it back in.
i know it the curcuit board works because i hooked it all up in the electronics lab thing with a breadboard, dpdt, pots, leds, etc. but when i wired it up and it didn't work, and doesn't matter if it's in the box or not.
the sound is ugly and decays real fast after i hit the strings hard with the amp up high. i went over some of the solders yester day and redid the questionable ones, and changed the batter, but it made no difference. any help is aprisiated.
Sounds like the typical misbiased transistor problem to me. Did you use a trimpot on the collector of q2?
As per javacody's suggestion, make sure the battery is at about 9V and the collector of Q2 is 4.5V, or at least between 4 and 5V.
Good luck
no, i didn't use a trimpot, or at least i don't think i did. i don't know what trimpot is. i checked the volteges on the transistors:
battery at 8.5
Q1
base------.03
collector--.00
emitter---.18
Q2
base------.18
collector--.00
emitter---.78
so, it's obvious that the leads are wrong, or something i don't know. which leads should be switched?
In any case one of those pins should be getting 4.5V or so - check the values of the resistors between Q2's collector and the voltage rail, something ain't right there.
i know :? and acording to ggg it's the collector on Q2. so maybe a little help from someone smart? :lol: i coulda sworn i had them right :(
Often times as soon as I think OK I got this one licked It throws me a curve like that.
Q2's collector should be around 4.5v - 6v, I suspect theres a miswire there in it somewhere...
These FF's can be tricky...don't sweat it, just relax and think of every way you can to apply the dmm and tryout the degugging page for more info...
I would start by measuring voltage on the 9V rail first. Make sure there isn't a cold joint there somewhere. If you're getting 9V on the rail, check it immediately after the resistor that leads to Q2-Collector. If you're getting 9V on the rail and only .7 or whatever after that resistor, chances are that's your problem. Just follow the trail of voltage and make sure its getting altered appropriately at each stage...
Look at your voltages. They are way too low. Somewhere you have a short or miswire.
When I asked if it worked out of the box, I meant that exact same board. If so, then it's hopefully just a short somewhere in the box.
hopefully that's true. i'm in computer aps right now, so i'll try that when i get home. thanks for the advise
it works :D !!! and oh man is it sweet. i got home like 2 hours ago, looked at the curcuit board for a while and saw this little tiny spot where two solder joints where connected. fixed that easy.
but i'm not done, i gatta get the LED curcuitboard working, the external 9v dc jack is whired worg and one other thing. does anyone know why when the gain is turned down past about 5 it starts to sound bad and after 3 or 4 is starts to crackle?
help is apriciated.
peace. rock on.
That first chord through a pedal you *just* got working is the sweetest sound in the world isn't it?
hell ya it is. actually, when i played the first test note, the fuzz was all the way down, so is crackled (i still wonder why). then i turned the fuzz up and WAM! :shock: it was sweet-ass-sweet.
Could that be one of electrolytic caps that has been too long in the shelf of the component shop, and it recovered :roll:
hmm...the electrolit caps where the only thing that i didn't buy from small bear. i bought the two from radioshack. that was dumb. :x
well now it doesn't work at all :cry: and i don't know why.
anybody?