Newbie - ic-386 clean boost very low volume

[jvanginkel]

Hello DIYers, my name is Joel and I'm trying to build my first guitar pedal. It's a Clean Boost pedal using an ic 386. It's from the Indyguitarist book. I'm not sure if I'm legally allowed to post a page from his book or not, you guys know more about that than I do. I breadboarded it first and got the right sound, but since I've put it on the veroboard I've gotten little to no sound. I used an audio probe and there's good signal at the input, at the input of the circuit board, through the first cap and even when I touch the input pin of the IC (pin 2). On the output side of the IC there signal is very, very weak. Even touching the output pin (pin 5). The volume is the same (very low) from pin 5 all the way to the output jack. I have a volume pot and a tone pot attached. I also am using a 3pdt and the bypass works perfectly. I have a stereo input and the led works like it should (only on when signal is going to the circuit board). I saw on some post that we should put some power readouts so here goes:

voltage out of the battery = 7.9v
voltage at the circuit board end of the red battery lead = 7.89v
voltage at the circuit board end of the black battery lead= 0v

IC readouts
P1=1.33v
P2=.09v
P3=.09v
P4=0v
P5=3.98
P6=7.88
P7=7.0v
P8=7.0v

Cap filtering power to ic:
positive=7.89
negative=0

Any help would be appreciated.


Joel

[anchovie]

Try a fresh battery - there's not much juice left in that one if it's reading less than 8 volts.

[jvanginkel]

I will put a new battery in. From what I've been reading it sounds like a ground issue. I just don't totally get what a proper ground scheme should be. It seems like every diagram I see is slightly different. I'll describe what I've done and then someone can tell me what's wrong.

The ground of the battery is soldered to the ring of the input jack
There is a wire connecting the sleeve of the input jack to the ground strip of the vero board.
There is a 220pf cap that is connected to the ground strip on the vero board and the signal on the same strip as the ic input
There is a wire connecting the 4th pin on the 386 to the ground strip
There is a wire connecting the negative of the polarized cap coming from the 9v to the ground strip
The volume pot is connected to the ground strip
The tone pot is connected to a capacitor that is connected to the ground strip
The output jack's sleeve is connected to the middle of the 3pdt switch which connects it to the LED
The output jack's sleeve is also connected to the ground strip on the circuit board.

Did I do something wrong?

Joel

[MikeH]

Hi- welcome!  Did you use a socket for the IC, or did you solder it in directly?

[jvanginkel]

I used a socket for the ic.

[MikeH]

Might be a dumb question; did you cut the traces under the IC?

[jvanginkel]

So, since i last posted, I saw that a lot of people send a wire from the ground of the input to the ground of the output, so I did that, I removed the ground wire from the input to the circuit board as well. I also resoldered the ic socket and now I have volume, but it has come along with a huge hiss. I wish I would've gone one step at a time so I knew what actually helped my problem and what may have created this new one. There is no hiss of anykind on the bypass signal, but unbelievably loud hiss on the signal going through the veroboard.

Joel

[anchovie]

So are you saying that your board now has no ground connection whatsoever?

Also, did you get round to putting a fresh battery in there?

[jvanginkel]

Yes I did put a new battery in. The board has a ground connection to the sleeve of the output.