# DC jack woes



## ericwood (Mar 22, 2020)

Hey pedal pals,

I've been building a few Informants for some friends; first one this morning went great (well enough to post in the build reports!), so I figured I'd have a go at another one. Essentially identical parts, all from the same order. It works! Until I go to box it up.

With everything secured in the enclosure, when engaged nothing happens, including the LED turning off. Since the dry signal passes through just fine when bypassed, that tells me right away it's a grounding issue, which would also explain why things were going great until the enclosure showed up. A little bit of troubleshooting later, I have it isolated to the DC jack; it seems the sleeve of the plug, by virtue of how the jack is constructed, gets grounded to the enclosure. This would make sense in a center positive world, but that is not the world we live in.

It seems the first build worked because the powder coating was thick enough to electrically isolate the power adapter, but on the second build it was not and my IO jacks were getting unexpected voltage (it is a miracle nothing is fried!). That's my theory, at least.

What I desperately need, though, is a sanity check! Digging deeper into the product page for the jacks (https://www.taydaelectronics.com/1614-19-lumberg-dc-power-socket.html), nothing pops out at me and screams "hey, watch out, we're going to connect the sleeve to whatever we're mounted to!" I'd also expect other people to run into the same issue.

So: am I crazy? Am I missing something about these jacks, or jacks in general? Am I the first person dumb enough to spend $4 on a DC jack and this is my punishment?

Thanks so much in advance!


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## ericwood (Mar 22, 2020)

Looking at the DC jacks page on Tayda I'm realizing "through hole" vs. "panel mount" might be a clue, although I see this one, which looks to be a much cheaper version of my problematic Lumberg jack, unless it's isolated in some way I can't figure out from the picture.


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## phi1 (Mar 22, 2020)

I think you’re understanding is correct. That dc jack shouldn’t be used for pedals due to center-neg / sleeve-pos. Use one of these. 









						DC Power Jack 2.1mm Enclosed Frame With Switch
					

Get It Fast - Same Day Shipping




					www.taydaelectronics.com
				












						DC Power Jack 2.1mm Panel Mount Round
					

Get It Fast - Same Day Shipping




					www.taydaelectronics.com
				












						DC Power Jack 2.1mm Enclosed Frame With Switch External
					

Get It Fast - Same Day Shipping




					www.taydaelectronics.com


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## phi1 (Mar 22, 2020)

I think the larger ones are sturdier and have more consistent insertion force. I’ve even had one of the smaller ones break on one my pedals after using it for a while. So I only use those when space is really tight.


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## ericwood (Mar 22, 2020)

phi1 said:


> I think the larger ones are sturdier and have more consistent insertion force. I’ve even had one of the smaller ones break on one my pedals after using it for a while. So I only use those when space is really tight.



Yea I've been using that middle one for most of my builds (it's nice looking and tiny), but I do have concerns about longevity. It also has to be screwed in from the inside, which is a little inconvenient for testing pre-boxing.

Is there anything on the datasheet of that lumberg jack that should have tipped me off it'd work that way? I want to experiment a bit with parts without repeating this.


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## phi1 (Mar 22, 2020)

I didn’t see anything on the data sheet for that one, although I like where you’re head’s at with wanting to read those. 

About pre-box testing, I highly recommend something like this (link below). Then you can test just the circuit without wiring up the switch and jacks, which makes troubleshooting easier if you do have an issue. And you can do all the off-board wiring in the box, which I prefer. 






						Test Box (BUILD ONE NOW)
					

My old test rig has run its course and I had this flimsy enclosure kicking around so I ordered up a few speaker terminals and a 3pdt toggle and went to town.  It’s bar none the easiest thing you can cobble together that will also be one of the most useful things on your bench.      All there is...



					forum.pedalpcb.com
				




Another thing you can do is use this for power when testing outside the box. 






						Search results for: 'hardware dc power dc power female jack push button'
					






					www.taydaelectronics.com


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## ericwood (Mar 22, 2020)

phi1 said:


> I didn’t see anything on the data sheet for that one, although I like where you’re head’s at with wanting to read those.
> 
> About pre-box testing, I highly recommend something like this (link below). Then you can test just the circuit without wiring up the switch and jacks, which makes troubleshooting easier if you do have an issue. And you can do all the off-board wiring in the box, which I prefer.
> 
> ...



Good point! I've been debating building one of these for a while now and this is pretty much the last little push I needed to go through with it


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## Robert (Mar 23, 2020)

Almost everyone has been down the "metal DC jack" road... it's a pedal building rite of passage.     

I recall the first time I ordered one many years ago, chuckling because none of the other pedal builders had sense enough to use such a rugged and nice looking _metal _jack... Fools!


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## falzhobel (Mar 25, 2020)

I still struggle to find a good power jack for my pedals.... The small one from Tayda is clean but it comes loose after 2-3 insertions. I found the big one (with the battery switched power) too big for my use.... I'm still searching.


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## phi1 (Mar 25, 2020)

Have you tried the lumberg thinline 2.1mm from LoveMySwitches ($1.25)?  They claim it is higher quality than the cheaper version they sell ($0.75). Maybe the cheaper version is the same one tayda sells, I’m not sure. I haven’t tried these, might be worth a shot.


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## BurntFingers (Mar 25, 2020)

I went back to the Boss ones. The little ones just come undone very quickly, the boss ones, although bigger, just seem to work. I bend the battery lug out the way or clip it off and just use the + and the - for the power.


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## zgrav (Mar 25, 2020)

For the original poster --  I suggest replacing the DC jack on your first build as well, especially if that is one of the ones you pass along to someone else.  The insulation provided by that powdercoat will be unreliable.


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## ericwood (Mar 25, 2020)

zgrav said:


> For the original poster --  I suggest replacing the DC jack on your first build as well, especially if that is one of the ones you pass along to someone else.  The insulation provided by that powdercoat will be unreliable.



That's the plan! Very much not in love with the idea of an electrified enclosure


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## Chuck D. Bones (Mar 27, 2020)

Robert said:


> Almost everyone has been down the "metal DC jack" road... it's a pedal building rite of passage.
> 
> I recall the first time I ordered one many years ago, chuckling because none of the other pedal builders had sense enough to use such a rugged and nice looking _metal _jack... Fools!



Yup, been there, done that.  On my first PedalPCB build (Ungula) I used a metal housing jack.  I knew it would short to the case so I drilled the hole oversize and used insulating shoulder washers to mount it.  Kind of a pain so I stopped using metal jacks.  Buuuuuuut, it's rugged as all get-out.  The all plastic jacks get mounted with a drop of crazy glue on the nut because the nuts don't stay tight and the plastic bodies can't take any torque.


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## Grubb (Jul 7, 2020)

Chuck D. Bones said:


> I drilled the hole oversize and used insulating shoulder washers to mount it.



Can you shed some light on this process for me please? I'm trying my first builds (Muroidea and LGSM) in the coming week or so and I firstly ordered plastic DC jacks from Tayda that were much too large for the pre-drilled enclosure holes and then I tried to rectify my mistake by purchasing jacks that fit from my local electronics store, but I now realise they are metal and it's likely going to cause problems. Cheers.


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