Help figuring this out

[dannyg]

Basically, Ive had trouble building my first pedal. It's a very simple fuzz.

Here is what happens:

First off, I plugged the DC jack in and bypassed the pedal, and got the amps clean sound. When it came to pressing the switch, nothing came through at all. But when I turned one of the pots it was sweeping a scratchy sound. I figured I would try to sort it out and unplugged the 9v jack. After doing this, I still got the amp sound because i was still plugged in. I then pressed the switch and got a rolled back version of what I got when the switch was bypassed.

I don't know what to do now because this should of been a very simple build.

[GREEN FUZ]

Unfortunately the information you`ve given isn`t extremely helpful to someone trying to diagnose the problem. My guess though is you`ve wired it up wrong. Check the wiring methodically. When you`re satisfied you did everything right the first time, check it again. Then once more. Then again. Repeat.

This may sound a bit smartass but I can`t remember the amount of times I thought I`d done everything correctly only to find somewhere down the line that two crucial wires had been transposed.

If all fails there is a sticky thread entitled DEBUGGING-what to do when it doesn`t work which you should read.

[dannyg]

Ive changed a few things but nothing really changed at all. I know it's too vague to point at specifics, but what is it most likely to be? LIke certain components?

[CGDARK]

Unfortunately the information you`ve given isn`t extremely helpful to someone trying to diagnose the problem. My guess though is you`ve wired it up wrong. Check the wiring methodically. When you`re satisfied you did everything right the first time, check it again. Then once more. Then again. Repeat.

This may sound a bit smartass but I can`t remember the amount of times I thought I`d done everything correctly only to find somewhere down the line that two crucial wires had been transposed.

If all fails there is a sticky thread entitled DEBUGGING-what to do when it doesn`t work which you should read.

That's exactly what I recommended to railhead yesterday "...Always double check (or check as many times as needed), because our eyes can play tricks on us..."

CG 

[dannyg]

I understand that, but is there a particular component associated for when things happen like this?

[GREEN FUZ]

What is the circuit you`re working on? If it uses transistors it/they may have been put in the wrong way round.

[dannyg]

It's an EZ face. It uses two transistors which I have socketed. SO turning the transistors was the first thing I tried.

[GibsonGM]

You need to check out the Debugging thread, and post that information.  Voltages of the transistors and so on will help others to find the problem.  It's pretty likely to be switch wiring, but could be something else.   

[dannyg]

1.Read my original post to see what doesn't work
2.Name of the circuit = EZ Face
3.Source of the circuit (URL of schematic or project) = http://img502.imageshack.us/img502/9483/ezfaceezri8.jpg
4.Any modifications to the circuit? Yes, I added a 9v dc socket.
5.Any parts substitutions? Yes, I used a AC187  instead of 2SB33
6.Positive ground to negative ground conversion? I was told that it is a positive ground.

[GREEN FUZ]

5.Any parts substitutions? Yes, I used a AC187  instead of 2SB33
6.Positive ground to negative ground conversion? I was told that it is a positive ground.

This might be your problem. The circuit is positive ground. The 2sb33 is, as far as I know, a PNP transistor. You have replaced it with an NPN trannie. Get yourself another PNP, anything will do for now. If you have another 2N3906, stick it in. Observe the pinouts closely. On the schematic the letters C, B and E relate to the COLLECTOR, BASE and EMITTER respectively. It is important that the correct leg fits in its corresponding hole. Pinouts vary from one trannie to another so if you don`t know what yours are you`ll need to find out.

[dannyg]

I have used the transistor that the schemeatic information said I could use as a sub. Strange?

[GREEN FUZ]

I have used the transistor that the schemeatic information said I could use as a sub. Strange?

Sure is, what can I say? This is the Joe Gagan easy face from GGG, right? The site is down at the moment so I can`t access it. Are you sure it didn`t say ac188?

It`s supposed to be a great sounding circuit so stick with it.

[dannyg]

It is the Joe Gragan one yes, but it's the EZ diagram i'm using haha. But then somebody was kind enough to draw me up a layout. Im pretty sure it is the ac189.

Luckily I have a printed copy, i'll scan it in.

[GREEN FUZ]

That`s a big ol` schematic ya got there.

Nevertheless, it just confirms for me that it is indeed positive ground. All the substitutes recommended are PNP.If you`ve used an ac187 it wont work.

[dannyg]

That`s a big ol` schematic ya got there.

Nevertheless, it just confirms for me that it is indeed positive ground. All the substitutes recommended are PNP.If you`ve used an ac187 it wont work.

Haha!

I'm using a ac128 not 127..

[GREEN FUZ]

Ok. The ac128 is fine. This still leaves quite a lot of probable/possible causes of your circuit`s failure. So, you`ve read the debugging thread. Have you got a multimeter? If you do and can provide the figures as instructed in the aforementioned thread you will find a lot of people on the forum will be very quick to help as the voltage readings give a lot of information. If that`s not possible the next best thing is to upload some photos, as clear as possible, both sides of the board.

[dannyg]

I cant get any clear photos, but I tried to scan it for fun before and it was crystal clear. I will try and scan them in tommorow. I'm going to see if I can get hold of a multimeter.

EDIT: can't seem to get the best of scans but here they are.

I had to disconnect the wire from the trimpot to the ground because it wasn't long enough to let the board fit the scanner. I know I should If taken all the wires off lol but I didn't.

Also, I can't get a good picture of the component side because the scanner blurs if it's too far away and the transistor are quite high up.

Ill post the layout aswell just incase it helps.

[dannyg]

Ive added the picture and layout.

[oskar]

Well it looks to me like you need to cut the copper tracks so not everything gets shorted...   
The drawing you followed has connective points and you've used a stripboard, judging from the picture you haven't
cut any of the tracks...

[CGDARK]

Your problem is basically that you didn't make any cut to the traces and all are shorted. And you have to redo the layout, because some parts are aligned with the traces and they are doing nothing in the circuit (ex. one of the transistors) or try to cut the traces.

CG