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is it my leads or is it my pedal?

Started by aran.e666, December 04, 2014, 08:23:43 PM

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aran.e666

Basically I just finished a cry baby gcb 95 on vero and I hooked it up. To no surprise it didn't work and later I found out it was a faulty switch. Still dosent work. When I say 'dosent work' I mean it works normally and no tone is lost which is the point of bypassing however when I engage the effect, I get nothing. Imagine unplugging your guitar when your amp is on and you get no sound but the faintist buzz (because of the amp). This is what im experiencing. I have ran a blade several times through the tracks and made sure it is wired up correctly but it still dosent work.  Any feedback or advice would be amazing! Like I say I have built many pedals before so I know it shouldnt be my soldering, maybe the caps? Thanks

Aran
Guitar is love, guitar is life.

jkokura

Hey Aran,

The problems could be quite a few, and the real key is to narrow down the issue by eliminating the things it isn't.

I'm going to move this thread over to the tech help area, and I recommend that you read the thread below for some debugging ideas. For instance, do you know you're getting power to the right places? Are you sure you have your signal going in and out of the pedal properly?

The tool you really need at this point is a good audio probe. If you haven't built yourself one, and you plan to build pedals, you should build one asap.

http://www.madbeanpedals.com/forum/index.php?topic=902.0

Jacob
JMK Pedals - Custom Pedal Creations
JMK PCBs *New Website*
pedal company - youtube - facebook - Used Pedals

aran.e666

Yeah ive got it wired up properly e.g two wires going to out and pos wire going to circuit etc. I cannoit yet find an issue but on the bright side the mpsa18 trannie I have spare from the order, now is in my seamoon funk machine and makes it sound so much better.  Anyways It might be the inductor?  Im using an axial 500 mh. Cheers

Aran
Guitar is love, guitar is life.

midwayfair

Quote from: aran.e666 on December 04, 2014, 08:55:29 PM
Yeah ive got it wired up properly e.g two wires going to out and pos wire going to circuit etc. I cannoit yet find an issue but on the bright side the mpsa18 trannie I have spare from the order, now is in my seamoon funk machine and makes it sound so much better.  Anyways It might be the inductor?  Im using an axial 500 mh. Cheers

Aran

Please read the entire topic Jacob linked to. It contains instructions for what we need to help you troubleshoot your project.

Without that information, it's like calling someone on the phone and saying that you've got a letter that doesn't make any sense, but they don't have a copy of the letter and you won't even tell them what the letter says. All anyone can do is guess. Maybe they'll get lucky and describe exactly what's wrong, but how likely do you think that is?

aran.e666

I guess il describe the problem then. So I guess it could be the input jack since its old but I have probed the wiring, checked it over 11 times and I see no fault. With the vero I have ran a blade down each strip and used a magnifying glass to cgeck and it looks ok. Maybe its the inductor, its axial. The values are all right and like I said its all wired up right because it bypasses nicely but dosent engage when I select  the effect. But it could be the pot wiring but I have done it as specified on the schem.

Aran
Guitar is love, guitar is life.

midwayfair

Quote from: aran.e666 on December 04, 2014, 09:33:22 PM
I guess il describe the problem then. So I guess it could be the input jack since its old but I have probed the wiring, checked it over 11 times and I see no fault. With the vero I have ran a blade down each strip and used a magnifying glass to cgeck and it looks ok. Maybe its the inductor, its axial. The values are all right and like I said its all wired up right because it bypasses nicely but dosent engage when I select  the effect. But it could be the pot wiring but I have done it as specified on the schem.

Aran

Look, I'm not trying to be a jerk, but again, please READ the post Jacob linked to and follow the instructions. It has a FORMAT for your post. It tells you to take VOLTAGES using your multimeter. It suggests taking PICTURES of both sides of the board. It provides numerous other diagnostic steps you should take and document before you post a tech help thread. Among other things that might not be obvious, you haven't linked to the schematic or even the layout you're working from.

We're all friendly here and many of us enjoy helping, but seriously, read the post and provide the information that Brian and Jacob instruct you to post. Until you provide all of it, we are just guessing and can offer no useful advice. Help us help you.

aran.e666

Well in the UK it is 11pm so im going off for the night but tomorrow I will take voltages, pics of the board and post the layout etc.

Guitar is love, guitar is life.

jkokura

Quote from: aran.e666 on December 04, 2014, 11:00:24 PM
Well in the UK it is 11pm so im going off for the night but tomorrow I will take voltages, pics of the board and post the layout etc.

Great! The key is figuring out where the signal stops. If the wiring is correct, than the signal is stopping somewhere on the PCB, so we need to figure out what's wrong.

9 times out of ten it's a simple mistake, and you'll be up and running in no time. Get us those voltages and be prepared to learn how to audio probe your PCB.

Jacob
JMK Pedals - Custom Pedal Creations
JMK PCBs *New Website*
pedal company - youtube - facebook - Used Pedals

aran.e666

Ok the voltages read - dc = 9.26v

Q1 C-8.22v B-2.14v E-3.36v

Q2 C-7.73v B-1.04v E-3.37v

Q3 C-7.54v B-5.23v E-6.81v
Guitar is love, guitar is life.

jkokura

Could you share the layout you're working from, and some good pictures of the guts of your pedal? We need to see your wiring, and your circuit and layout will be a big help in determining if your voltages are correct.

However, the fact that you're getting power to the PCB is a very good sign. Perhaps knowing if you have signal at the input and output of the PCB (not the switch, the actual PCB) that would help. The best approach is tracing backwards from the output to where the audio stops, then you'll know where to start.

Jacob
JMK Pedals - Custom Pedal Creations
JMK PCBs *New Website*
pedal company - youtube - facebook - Used Pedals

midwayfair

Quote from: jkokura on December 06, 2014, 10:22:07 PM
Could you share the layout you're working from, and some good pictures of the guts of your pedal? We need to see your wiring, and your circuit and layout will be a big help in determining if your voltages are correct.

And the schematic the layout was from.

Without more information, the best I can say is that there are very few situations where the emitter of a BJT being used as an amplifier or buffer can possibly be higher than the base voltage. It should be .7V lower as a rule. Therefore, you've missed a connection, shorted a connection, or failed to make a cut on the vero.

aran.e666

Ok il try and send a few pics, I see what you mean with the voltages. Thanks

Aran
Guitar is love, guitar is life.

aran.e666

Heres sadly the best shot of the guts
Guitar is love, guitar is life.

jkokura

JMK Pedals - Custom Pedal Creations
JMK PCBs *New Website*
pedal company - youtube - facebook - Used Pedals

aran.e666

Oh god clicked wrong pic (epic facepalm) :-[
Guitar is love, guitar is life.