DoD 250 short circuit problem, output jack...

[guitar.a]

Hi... I'm new to the forum .... I made a DoD 250 pedal, the gray version, which is not so relevant to my question. And the next question is, why is there a short circuit on the output jack? This happens when I build any DoD overdrive pedal, and 308, 250 any version. The part with the clipping diodes is very strange to me, and because of it, I get a short circuit. It happens when I turn the volume pot. No one has been able to help me so far, I connect everything nicely. Can any of you? Thank you.

[GibsonGM]

welcome - got pix?

[idy]

Yes, welcome and pictures please. They will answer many of our questions.

[guitar.a]

Here's the pictures.  I used this scheme.  I connected the 3pdt like this, only without the led diode, and this time "from circuit output" goes to the middle pin pot, you can see this in my photos.

[antonis]

I connected the 3pdt like this, only without the led diode, and this time "from circuit output" goes to the middle pin pot

Do you mean to the lug 5..??

[guitar.a]

I am a beginner in making pedals.  As for the potentiometer, I used the most common ones, as can be seen from the given photos.  They have 3 pins.  Is it a mistake that I used these ordinary potentiometers?  I'm not familiar with other types of potentiometers, I haven't really encountered them... Thank you for your understanding!

[antonis]

May I ask once more..??

I connected the 3pdt like this, only without the led diode, and this time "from circuit output" goes to the middle pin pot

Do you mean to the lug 5..??

[andy-h-h]

I am a beginner in making pedals.  As for the potentiometer, I used the most common ones, as can be seen from the given photos.  They have 3 pins.  Is it a mistake that I used these ordinary potentiometers?  I'm not familiar with other types of potentiometers, I haven't really encountered them... Thank you for your understanding!

Those pots are fine to use.  I'm guessing you don't have a multimeter to check voltages or a signal probe?

Questions

- What does underneath the board look like?  Can't see any connection with those photos.
- The layout you posted doesn't appear to match your build - what layout did you use?
- does it work outside the box?


I can see a 470n cap instead of a 47n on what I think is ht input.  Won't be the cause of your problems, but might want to check your values.

[guitar.a]

47k63 is the appropriate capacitor as far as I know.  I have a multimeter.  I didn't arrange the components in the same order as in the picture, so to speak, but they are connected like that, there are no small cables under the board that could make a short circuit somewhere. The fact that I did not arrange the components as in the picture does not mean that they are not nicely connected under the board. I also checked that the socket is not short-circuited, as for the jack input, I checked which input is ground and which is hot.  I can take a picture of the plate from below, but I don't know how well you could interpret the connection through the picture, but I could mark it on the picture.  When I was building the DoD 308 before, I took it to an electronics technician because of this problem, who was unable to solve this problem, but concluded that I connected everything well then.  Regarding this pedal specifically, here is a brief explanation of the part causing the problem, as I connected it: On the 3pdt, the out jack is connected to the + of the jack.  The same end as put in this picture of the connected 3pdt, when it is turned on, that out signal from the jack actually goes to the middle pin of the pot, that is with the 3pdt, and the first and third pin on that same volume pot, one is connected to all  the main ground, while the remaining one goes to the negative of the capacitor, that is, one end of the clipping diode, like on this scheme. Regards!

[andy-h-h]

The usual thing to do around here is to post the schematic, the layout used, photos of your work and voltages on the IC as a starting point - otherwise it's just a guessing game and people may not even try to help you.

I'm having trouble understanding what you are trying to say, especially the last couple of sentences - I guess English is a second language, which means you probably speak at least one language more than I do  and is also in part why decent photos are very handy

To me the cap appears to be .47K63 which I thought equates to .47u / 470n  K = 10% tolerance   63v  Anyways, you sound like you have bigger problems to deal with.

Good luck 

[ElectricDruid]

May I ask once more..??

I connected the 3pdt like this, only without the led diode, and this time "from circuit output" goes to the middle pin pot

Do you mean to the lug 5..??

You need to explain more, Antonis. You're so succinct you're practically a haiku

I'm guessing that you're talking about the connections between the circuit board and the 3PDT switch. And I agree that does seem like the most likely source of the problems, especially if this keeps happening to the OP. It's highly unlikely that *all* their builds have the same fault, but repeating the same error in 3PDT wiring might well cause all the outputs to be shorted.

My first test would be to solder the PCB input/output wires direct to the jacks (remove the 3PDT from the circuit) and check that the circuit works like that. After that, work on wiring the switch back in and getting it running with the 3PDT bypass included.

PS: guitar.a, get some different colours of wire for wiring up your enclosures. It'll save a lot of confusion.

[GibsonGM]

I always test each board when it's done before connecting switching, power and audio jacks by using jumpers to connect the jacks and a battery. This ensures that the board WORKS, before putting in switching / enclosure, so that problems are much more obvious if they happen at the assembly stage! 

[antonis]

You need to explain more, Antonis.

Honestly Tom, I haven't the slightest idea about what's happening here..
(e.g. shorted diode, defective IC, open pot....)

OP claims a "short circuit" on output jack without any further info..
(which could be a signal axis open circuit, as well..)

[ElectricDruid]

You need to explain more, Antonis.

Honestly Tom, I haven't the slightest idea about what's happening here..

No, no, I mean "explain about what lug 5 is"! I guessed you're talking about the 3PDT because it's the only thing apart from the IC with more than three legs, but that's me extrapolating, not you explaining!

Don't worry, I don't expect you to already know what the problem is!

[guitar.a]

Respect to all!  Thank you for your help and for understanding me.   Yes, it's a bit awkward for me to write in English because it's my second language.  Here are the photos, I tried to take pictures so that everything can be seen.  I know that it is awkwardly connected under the board and that it is more difficult to understand... I removed all the cables, as you can see, I also marked to make it a little clearer how I connected, the emphasis is on the potentiometer itself, the inputs, the switch.. If you need something a little better to take a picture of, say so. Once again, many thanks!

[Govmnt_Lacky]

Looking at the photos, it appears that you are using Mono jacks BUT, each jack has shunts. This means that when a jack is not inserted, the signal automatically gets "shunted" to another contact on the jack.
It also appears that the jacks may not be wired the same way.

YOu should check the Input and Output jacks with a multimeter to see if you are not shorting the signal. From the looks of your picture, it appears that one of those jacks is not wired properly.

[guitar.a]

Yes, I'm using mono jacks, but... I checked that the jacks are not shorted, and they are not.  Also, before connecting, I tested by inserting a jack cable into them, put one end of the multimeter on its hot, and with the other end I tested where the hot is on the jack.  Likewise for grounding.

[Govmnt_Lacky]

Yes, I'm using mono jacks, but... I checked that the jacks are not shorted, and they are not.  Also, before connecting, I tested by inserting a jack cable into them, put one end of the multimeter on its hot, and with the other end I tested where the hot is on the jack.  Likewise for grounding.

Then I guess my question is "Why are the jacks wired differently?"

If using the same jack(s) for Input and Output, then they should be wired the same (mirrored) and yours do not look like they are from your pictures.

Does anyone else see this??

[guitar.a]

I understand completely, and the question is quite appropriate.  And my answer is that the socket has 4 parts. That's closed tipe of jacks.  Some are connected and have exactly the same function.  That is the reason for this binding.

[duck_arse]

Yes, I'm using mono jacks, but... I checked that the jacks are not shorted, and they are not.  Also, before connecting, I tested by inserting a jack cable into them, put one end of the multimeter on its hot, and with the other end I tested where the hot is on the jack.  Likewise for grounding.

Then I guess my question is "Why are the jacks wired differently?"

If using the same jack(s) for Input and Output, then they should be wired the same (mirrored) and yours do not look like they are from your pictures.

Does anyone else see this??

oh, me! me! I see it!

the jack on the left is wired tip and sleeve, the jack on the right is wired ring and sleeve. [going by ordinary tayda jacks.]