# Waddle Box Problems



## Alexander Maier

Hello, 

today I received my kit for the Waddle Box (DOD FX25 Clone). The documentation was very good and I build the parts together. When I tested the Waddle Box I can only hear a constant noise. I have looked at all and I think everything is build together as it should be. All parts are on the right place. The D1, D2, D100 was inserted as the ring on the diode goes to the quatratic hole. 

What can be the problem? 

Thanks

Alexander


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## zgrav

really hard to say with that little information.   could be lots of things.  you need to provide more info and pictures of both sides of the board.
1.  does the bypass work OK?   2,  is power connected properly?  3.  are any ICs oriented correctly?  4.  same for transistors  5.  is the noise in the circuit only there when a guitar is plugged in?  6. Does the noise change when you turn the pots on your effect?  What about when you turn the knobs on your guitar?    what are the voltage readings on the ICs or transistors in the circuit?       those are the same questions you need to go through yourself as well to try to figure out what might be wrong with a pcb project ---  sometimes you will figure the problem out and get it working right away, other times you will use that info to share with others on a forum and get suggestions on what to check next.


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## Alexander Maier

Thanks for the information. I have made some pictures. 

1.) The Bypass works
2.) The Power Connection is ok. LED is running and I measured 9V on the platine.
3.) The IC's - I think - are orientad correctly
4.) The transistors are oriented correctly
5.) The diodes are oriented correctly - I think
6.) The noise is only on the output signal when the pedal is activated (no noise at bypass). There is no change when the pots (on the pedal or guitar) are turned.

I have made a test: On the input signal I have running some MP3 player (to get continuous input) and I get a full output when bypassed. When the pedal it active I get a noise (ground smoking - I do not know the right translation) an a very low signal of the MP3 input. 

I think I will solder the connections of the pots better. Where do I have to measure the voltage on the IC's.

Alexander


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## zgrav

Your overall construction looks good.  I don't see any likely shorts on the board.  You can check the circuit diagram in the build docs to see where the power is supposed to go in the board.   most folks will turn then knobs on a project fully in one direction and take the  voltage measurements at every pin on an IC and write them down.  then turn the knobs in the other direction and write down the voltages again.  you do that because some projects are changing the voltage on a chip when you rotate the dials.  I don't know if the pots on your project would affect the voltage on the pins.  for that matter, I'm not quite sure what the Waddle Box is supposed to do.  Usually with a sensitivity adjustment it would either be a "wah" type of filter effect, or maybe a noise gate.  either way you should be getting some signal going through it, an no noise drowning it out.

are you also sure that you are putting your sound into the "IN" jack and have the output going to the "OUT" jack?  the bypassed signal still works either way, but not the effect.  sometimes it is easy to get the plugs reversed when you are testing them out of the box.

I would also use your soldering iron and retouch all of the connections on your resistors and your capacitors to make sure they have shiny solder on them and are connected to the PCB.


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## Alexander Maier

I am sure to used the correct jacks - I also tried it in the "wrong" way. Bypass is perfect. I have retouched all connection with my soldering iron. The "noise" is now not hearable, only a little rustle (what can be from the preamp of my poweramp). I also measured all connections with the ports in the middle and noted them on the picture. Then I have looked on the diagram an looked for the connections between the parts. There I have checked the measured voltage. All seams ok.

But I have learned that a resistor reduces the voltage. But I have a lot of resistors (R8, R7, R6, R13, ...) where the voltage on both pins seams to be the same. I myself ask me: What would be the correct voltage values to be expected?

I hope the screenshots are ok.


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## Robert

That is very thorough voltage measurements, excellent!

Something is definitely odd about the voltages around IC1...  Can you pull out the IC and measure the voltages on each pin of the IC socket again?


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## Alexander Maier

Thanks! I have now measured with the IC1 pulled out at the pins from IC1. The IC1 is MC1458P (this should be the same als LM1458). The IC2 is LM13700N. I have got the kit from a German distributor. Could this be the problem?


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## zgrav

Nice job with the pictures and voltage measurements and it should help isolate the problem.  And good to know your work reflowing the solder got rid of the noise in the circuit.


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## Robert

Do you have another dual opamp you could pop in there and try?    TL072, JRC4558, etc?

It certainly _appears _like that opamp is defective.


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## Alexander Maier

I don't have another opamp. But I will go shopping tomorrow and I know there is a electronic parts reseller. Probably he will have one to sell


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## zgrav

Pick up a half-dozen if they are inexpensive.  Nice to have spares on hand.


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## Alexander Maier

I bought a new opamp MC1458P and replaced the one inserted. Still no effect, but if I increase the gain on my amp I get a pulsating noise when the effect is on. Bypass works. So I measured once time.


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## Robert

Hmmm, so the voltages have changed considerably, and are closer to what would be expected, but still not quite right...

Just for the heck of it, can you pull out IC2 (leave IC1 installed) and remeasure the voltages around IC1?


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## Alexander Maier

Ok, I pulled out IC2 and leave IC1 installed.


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## Alexander Maier

Robert said:


> Hmmm, so the voltages have changed considerably, and are closer to what would be expected, but still not quite right...
> 
> Just for the heck of it, can you pull out IC2 (leave IC1 installed) and remeasure the voltages around IC1?


What should be the right values?


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## Robert

You should have something in the neighborhood of 4.5V on pins 1, 2, 3 and 5, 6, 7.   Your voltages on pin 4 and 8 are normal.


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## Alexander Maier

Robert said:


> You should have something in the neighborhood of 4.5V on pins 1, 2, 3 and 5, 6, 7.   Your voltages on pin 4 and 8 are normal.


Ok, I have looked at the diagram and measured the following:

Input 9V Power --> D100 --> 8,72V --> R101 (22k) --> 4,02V (VREF) --> R2 (470K) --> 0,54V --> PIN3 on IC1 

After this three resistors there is not something in the neighborhood of 4.5V. Seams that the resistor values are not correct? Make it sense to check the others?


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## Alexander Maier

Also there is a resistor R4 (1M) between Pin 6+7 of IC1. Is it possible that there can be about 4,5V on both pins?


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## Robert

R2 should "pull up" pin 3 of IC1 to near Vref (4.5V).   Pin 3 is high impedance so there should be very little voltage dropped across R2.  Pin 1 and 2 should follow.

I just noticed something about your voltage measurements in the most recent picture.  You have 4.49V on the left side of R3, but 0.47v / 0.55V on Pin 5 of IC1.    Something isn't right there.   Those two points are directly connected and should read the same voltage.   If those measurements are correct there must be a damaged trace there.


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## Alexander Maier

Thanks, I have carefully measured once more with no signal on the input and all IC's inserted. On pin 1,2 and 3 of IC1 I have only about 3,65-3,95V. On pin 5 there are 3,19V als about on pin of R3.

R100 is about 0V - My LED has stopped working  But I think this is not actually a problem.

What I see is that there is about 8,2V on pin 7 of IC1 (also on the connected pins of R4 and C4)

---

I have now spend lot of time about measuring and there seams not be a end. The waddle box is closed to the basket bin


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## Alexander Maier

Hello, 

today I received my kit for the Waddle Box (DOD FX25 Clone). The documentation was very good and I build the parts together. When I tested the Waddle Box I can only hear a constant noise. I have looked at all and I think everything is build together as it should be. All parts are on the right place. The D1, D2, D100 was inserted as the ring on the diode goes to the quatratic hole. 

What can be the problem? 

Thanks

Alexander


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## zgrav

Not the basket bin!  : ^ )  My suggestion is to put is aside for now and build another pedal that interests you.  Sometimes you can come back to a project with fresh eyes and find a problem that you could not find before.  And it may turn out to be something very simple.


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## Alexander Maier

zgrav said:


> My suggestion is to put is aside for now and build another pedal that interests you.


This I have done  It was a Schalltechnik04 Pumpernickel Compressor - Great pedal - and it works fine


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## zgrav

Did you drill the case holes?  The LEDs look nice!


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## StephanCOH

Alexander Maier said:


> This I have done  It was a Schalltechnik04 Pumpernickel Compressor - Great pedal - and it works fine



Wanting to build a Pumpernickel for quite some time now. Did you drill the enclosure yourself?


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## Alexander Maier

StephanCOH said:


> Wanting to build a Pumpernickel for quite some time now. Did you drill the enclosure yourself?


No, I didn't drill the enclosure myself - it was my son  . Not really difficult, but you have to drill slowly, carefully and accurately with a pillar drilling machine.


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## Alexander Maier

I have seen that the listed 22k resistors are delivered as 22.6k resistors. I think this is the problem that I didn't get 4,5V round of IC1.


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## Robert

As long as they were both the same value that shouldn't have made much of a difference.   I've seen the resistors in a Vref voltage divider range anywhere from 4.7K up to 1M each.

BTW that compressor build looks fantastic.


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## Alexander Maier

Me once more  I have change IC1 and also put the diagram into LTSpice to get some values. The currently measured values on IC1 and IC2 are close to the expected values from LTSpice.


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## zgrav

You have done a great job recording the voltages in your circuit.  Do you have an audio probe?  They are easy to make and will let you listen to your input at different points on your circuit board.  It is just an audio cable that plugs into an amplified speaker, with the ground attached to your circuit board ground, and the lead wire goes through a capacitor to block any DC voltage going to your speaker.  You can find examples if you do a google search.  With an audio probe, you start by putting a signal into the PCB and touching the probe to the input jack to hear it there, then to the input on the PCB to make sure it reaches the board, then on the other side of the first capacitor the sound goes through, etc.  When a board is not working as expected, you will find the spot where things are wrong.


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## Alexander Maier

I don't have experience with an audio probe. But I have found something like a cable with a capacitor. Shorty used some spare parts 

I connected my notebook on the input jack running a web radio to get a "constant signal". The I connected the ground cable to the enclosure. Now I bypassed the pedal with the switch connect the hot cable to the hot pin on the input jack. I hear a the full sound from my speaker.

Now I activate the pedal. Attached the hot cable to the hot pin on the input jack. I hear a very low slightly modulated signal from my speaker. This it the same low slightly modulated signal on the output jack of the pedal and on some IC pin's. -> Should this be correct?


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## zgrav

try not putting sound in the input and using your probe to see if you still get noise in the circuit starting at the input and going through toward the output.


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## zgrav

also -- since you are getting noise coming into your signal path even at the input, I suggest trying a different wall wart for power and see it it makes a difference.  I had one instance where the wall wart I used to test an effect went bad and became noisy.


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## Alexander Maier

zgrav said:


> also -- since you are getting noise coming into your signal path even at the input, I suggest trying a different wall wart for power and see it it makes a difference.  I had one instance where the wall wart I used to test an effect went bad and became noisy.


I didn't get a "noise" at the input of the signal path. I am getting a very, very quiet signal when I activate the pedal in comparison when the pedal is in bypass mode. Even on the output, input and one some pins inside. The signal is slightly modulated, but that makes sence. The waddle box should modulate (envelope filter) the signal.


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## zgrav

thanks for the clarification.   so the level of the signal within the effect is very quiet compared to the bypass.   use the audio probe and start at your footswitch where the signal comes in from the input jack, and compare it to the ppare of the footswitch where it goes to the pcb when it is switched on.  The sound level should be the same there.  Is it?   If the sound is lower going to your PCB than it is coming in from the jack to the footswitch, I would disconnect the wire going to the pcb and see if that makes a difference when you test the sound at the footswitch.  If the sound level is low coming out of your footswitch even if it is not connected to your PCB, you might have a bad footswitch.  You can connect the wire from the input jack to the "in" pad on the pcb to take the switch out of the circuit and see if that makes a difference in what you hear.    If the sound only gets lower level when the wire is connected to the PCB, use your audio probe and the circuit diagram to see if you find different sound levels where the signal goes into different parts.  test the points where sound goes into each IC and out of each IC.


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## zgrav

another way to get a good feel for using the audio probe is to use one of your effect pedals that works OK to explore different parts of the audio path and compare it to the circuit diagram for that project.  in general, your incoming audio should be at about the same level going into an effect until it reaches either a pot (or trim control) or an IC or transistor.


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## Alexander Maier

So I now had some time to "play". I "disabled" the footswitch by wiring the cables together. Then I used my audio probe cable.


Input jack - Sound ok.
After C1 - Sound ok.
After R1 - Sound ok.
Pin 3 of IC1.1 - Sound ok.
Pin 1 of IC1.1 - Sound pulsating and little less signal
Before R6 - Sound equal to Pin 1 of IC1.1
Pin 3 of IC 2.1 - No Sound (not correct, very very low signal)
Pin 5 of IC 1.2 - No Sound (not correct, very very low signal)

So I changed IC1 to two other new IC's. -> The same.
So I pulled out IC1 and bridged Pin3 to Pin1 -> The same.

The only idea I have is to rebuild the kit with new parts. -> So time for the trash bin!


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## zgrav

Sometimes it helps to build another one and get it working.  If you do, I would keep this one and compare it to your working one to see where the differences are inside the circuit so you can fix it and have two of them, or pass one along to a friend.

If you wanted to keep looking at your project, from what you posted above, it would be worth figuring out why you have OK sound before R6, but then you don't have OK sounds at pin 3 of IC 2.1      See if the sound is OK on the other side of R6.  If the sound on the other side of R6 is different from what you get at pin 3, of IC 2.1, then something is wrong in that part of the circuit because the "back side" of R6 should have a direct connection to pin 3 of IC 2.1


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## Alexander Maier

I gave the project some time. First of all I pulled out the ics, soldered out all cable and all capacitors. Then I measured the connection between all parts according to the diagram. Seams there is all ok. Then I measured all resistors. And - I first was happy - all 22k resistors had a value about 11-14k. Did I found the problem. I soldered out all these 6 wrong resistors. That was R9, R10, R11, R16, R17, R102. After them I measured the resistors outside the board. All values are 22k. That was why I first was happy. So I decided to pull all parts back to the board. Then I measured these 6 resistors (from the side of the soldering) and the values are between 11-14k. 

Why ??? I don't understand this


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## zgrav

The resistors on  a board can have multiple paths that connect through other components.  So when you are measuring each side of a resistor on a PCB there can be multiple paths through other resistors on the PCB, so your the resistance you measure will be lower than just the value of that one resistor.


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