Struggling to find a specific type/ size of 12v DC PSU connector/ adapter

Thread Starter

manlikemike2019

Joined Apr 6, 2019
12
Hi - first post :)

I'm building a piece of furniture (a table) that will have a DJ Mixer recessed into the top surface. This presents a few problems as the power switch for the mixer is on the rear panel-once recessed it won't be reachable.

The mixer is powered by a 12v power supply. So, my idea was to put an 'inline' rocker switch and extension cable between the mixer's power supply and the unit itself; the idea being that I could leave the power switch on the mixer pushed in e.g. 'on', then mount the inline switch on the desk itself, somewhere out of sight but reachable, enabling me to power the mixer on and off as normal.

On ordering the inline rocker switch and extension cable, I found that they use connectors of a different size to the male connector on the mixer's power supply (and it's female receptacle counterpart on the mixer's rear panel itself). Obviously something I should've double checked but didn't think to-I must say that outside of the industry standard/ typical audio connections, I'm a bit of a noob when it comes to connectors in general.

So now my only option is to find a short male to female cable that is the same size as the connectors that the mixer uses. Then chop the short male to female cable in half and solder the female side to the end of the rocker switch that the mixer's power supply needs to plug into, and solder the male end onto the end of the extension cable (coming from the other side of the rocker switch), so that it can plug into the mixer's receptacle. Really confusing way to do it but seems to be the only way I can think of doing it as all the rocker switches I've seen of this sort only use the 'wrong' size connectors for what I need.

Anyway, I'm having a really hard time finding what type/ size of connector the mixer's power supply uses. From measuring the diameter of the outside of the male power supply connector it seems to be around 5mm or 5.5mm. It's one of the connectors that has a very small, thin pin inside of it. Picture of mixer plug and rear panel dc receptacle (bottom left of rear panel) below:

MOD: smartened up your images, so that the connectors can be seen.E

Please check I have the correct order.

Img_2122.jpg
djm-450-rear copy.jpg


Whereas the rocker switch and extension cable connectors are much thicker but the other way around-the female connector has a big pin inside and the male connectors are just hollow (pictures below to illustrate this):

Img_2120.jpg Img_2121.jpg
At this point all I know is that the inline switch and extension connectors are the '5.5mm x 2.1mm' size... So now any help to establish the size of the mixer female and male connectors would be greatly appreciated! Thanks
 
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djsfantasi

Joined Apr 11, 2010
7,826
You can purchase male-female connectors with pigtail ends and just replace the odd connectors. Cut the odd connectors off and replace with new ones. A couple of joints to be soldered and insulated with heat shrink tubing. (I don’t know where you live, but heat shrink tubing can be bought at most auto supply stores)

I’ve quickly looked through my orders and couldn’t find where I bought these. But this is what they look like.

28CC19EF-0EC1-45AE-BF73-296CDF388CEA.jpeg
 

LesJones

Joined Jan 8, 2017
3,486
As well as the common sizes of power connectors with 2.1 or 2.5 mm centre pin there are also a versions with a 1.5 mm and 1.7 mm pin. It could be that type. Here is some information on this range of connectors.

Les.
 

Thread Starter

manlikemike2019

Joined Apr 6, 2019
12
You can purchase male-female connectors with pigtail ends and just replace the odd connectors. Cut the odd connectors off and replace with new ones. A couple of joints to be soldered and insulated with heat shrink tubing. (I don’t know where you live, but heat shrink tubing can be bought at most auto supply stores)

I’ve quickly looked through my orders and couldn’t find where I bought these. But this is what they look like.

View attachment 174315
Thanks. Yeah I'm aware I could just cut the correct connector off the OEM power supply, solder the chopped end to the other end of the rocker switch and use the cut off connector on the other end to go to the mixer. However the mixer is under warranty still, so I'd rather not mess with anything that could void the warranty (from my experience, Pioneer usually wants you to return it with the original power supply if something goes wrong) - it has a couple digital effects units and a digital soundcard inside it too so this is not something I'd be comfortable just trying to fix myself, if it were to ever become faulty.
 

Thread Starter

manlikemike2019

Joined Apr 6, 2019
12
Thanks. Yes from measuring it with a tape measure, it seems to be inside diameter of around 3mm, outside diameter of 5mm and the pin inside can't be much more than 1mm.

Hard to tell really as I've seen a few where the inside diameter is 3.3mm, outside is 5.5mm etc
 

Yaakov

Joined Jan 27, 2019
3,482
Thanks. Yes from measuring it with a tape measure, it seems to be inside diameter of around 3mm, outside diameter of 5mm and the pin inside can't be much more than 1mm.

Hard to tell really as I've seen a few where the inside diameter is 3.3mm, outside is 5.5mm etc
First thing to buy is a pair of digital calipers. You can get them cheap and they will make your life a lot easier.

You can probably get them locally, but you can surely get them online.

https://banggood.com/150mm-Stainless-Steel-LCD-Display-Digital-Caliper-6-Inch-Fraction-MM-Inch-High-Precision-Stainless-Steel-LC-p-1373616.html for example.
 

LesJones

Joined Jan 8, 2017
3,486
It can sometimes be difficult to measure the diameter of the centre pin. One easy way to get an idea of the diameter of the hole in the socket is to try to see which is the largest size metric drill bit shank that fits into it. In a cheap set of metric drill bits (£3.99 from Aldi) they start at 1.5mm then 2.0mm, 2.5mm 3 mm and so on. As you have found that 2.1 mm is too large then from memory of the table I provided the link to the two sizes below that are 1.7 and 1.5mm So if a 1.5 mm bit fits snugly it is probably 1.5 mm If it is a sloppy fit it is 1.7 mm. A better quality set of drill bits will probably increment in size by smaller amounts.

Les.
 

Thread Starter

manlikemike2019

Joined Apr 6, 2019
12
It can sometimes be difficult to measure the diameter of the centre pin. One easy way to get an idea of the diameter of the hole in the socket is to try to see which is the largest size metric drill bit shank that fits into it. In a cheap set of metric drill bits (£3.99 from Aldi) they start at 1.5mm then 2.0mm, 2.5mm 3 mm and so on. As you have found that 2.1 mm is too large then from memory of the table I provided the link to the two sizes below that are 1.7 and 1.5mm So if a 1.5 mm bit fits snugly it is probably 1.5 mm If it is a sloppy fit it is 1.7 mm. A better quality set of drill bits will probably increment in size by smaller amounts.

Les.
Good tip, thanks Les. Just tried a 1.5mm drill bit and it looks close but doesn't fit at all. So I guess the pin must be more like 1mm. I've found a couple potential connectors on a UK site called Farnell so will get them (they're only £1 each) and see which fits.

In terms of the receptacle I found a potential one, but it's only one that would be mounted on a metal case then solder directly to. So I guess it worst comes to worse I'll just try soldering that on then get some big heatshrink tubing to fit around the metal contact parts.
 

Thread Starter

manlikemike2019

Joined Apr 6, 2019
12
Actually I also found this:

https://uk.farnell.com/lumberg/1614-21/power-entry-rcpt-10a-20vdc-flange/dp/2523617

If it fits the connector then it would be good as the table actually has 6mm MDF sheet fitted on the rear panel (to hide unsightly wiring/ spaghetti wires), so I could drill a hole in that then mount it directly to the MDF board - that way the power supply connector would just plug directly into it and be a nice clean, secure connection.
 

Yaakov

Joined Jan 27, 2019
3,482
Alternatively, you could put an AC socket inside the table, a mains entry module on the outside, and plug the original adapter in, inside your cabinet.
 

Thread Starter

manlikemike2019

Joined Apr 6, 2019
12
One noobish query with that receptacle though - it states that the current rating for it is 10A - I'm assuming because plug going into it is only 2A (e.g. less than the max current rating) then it would be OK to plug the connector into it?
 

Yaakov

Joined Jan 27, 2019
3,482
One noobish query with that receptacle though - it states that the current rating for it is 10A - I'm assuming because plug going into it is only 2A (e.g. less than the max current rating) then it would be OK to plug the connector into it?
Yes. That's a maximum rating and so long as it exceeds what you need you are OK.
 

Thread Starter

manlikemike2019

Joined Apr 6, 2019
12
Hey everyone :)

So I managed to find the right barrels, it was 3.3mm inside diameter, 5.5 on the outside and with a 1mm pin. I managed to get a male plug and also a female barrel (like the one on the mixer itself). So I created this combination of wires to connect it all up, it's a bit confusing but I wanted to be as clear as possible so that anyone can see where I might've gone wrong:

1. OEM power supply cable 1 - 3 pin UK plug, 2 pin IEC on the other end plugs into the OEM 12v adapter 'box'
2. A wire comes out the other end of OEM 12v adapter 'box', down a length of wire and finishes in a 3.3mm/ 5.5mm male plug
3. The first cable I had to make - a 1.5m standard 2.1/5.5mm DC extension cable, however I chopped the male end off and instead soldered the 3.3/5.5mm female barrel that I bought onto the end instead. The 3.3/5.5mm plug from the original 12v PSU from point 2 plugs into this 3.3/5.5mm female barrel
4. Now, the other end of this wire ends with a female 2.1/5.5mm plug - this end plugs into the male end of standard 12v rocker switch I bought
5. Then I've plugged the female end of this rocker switch it into a 2nd 1m 2.1/5.5mm DC extension cable (male end obviously)
6. Lastly, I've replaced the male end of this last cable with a male 3.3/5.5mm plug
7. Having replaced this plug allows me to plug it into the 12v DC receptacle on the back of the mixer

However... After all that, it doesn't work! The mixer powers on very momentarily (the manufacturer logo flashes up on the LCD screen on the mixer), then it just turns off again. Then after that no amount of turning the mixer on, switching the rocker switch back and forth or unplugging/ connecting all the cables will make it power back up. I've got it to power on and off twice now and that's it. Just to be clear plugging the OEM PSU directly into the mixer does still power it on perfectly fine. Really annoying. Does anyone know why this could be? Could it just be too long a combination of cables, too many different connections to carry the power sufficiently? I didn't think that would make a difference if I'm honest. And I don't really see any solution - I really needed the rocker switch in there as the wall socket itself will be covered by the piece of furniture (so won't be able to turn off at the wall).

The nominal voltage of the male one is 13.5V DC, nominal power is 2A. I believe the female one is the same. Lastly the DC extension cables are rated at 60 VA maximum, and meant to be suitable for all DC applications.

Thanks!
 

Thread Starter

manlikemike2019

Joined Apr 6, 2019
12
Sure... Long reply but here we go... First off the whole combination in one pic - from left to right: UK plug socket end - OEM 2 pin IEC plugged into OEM 12v PSU box followed by the wired in 12v cable and male plug, homemade cable starting at 'soldered on' 3.3/5.5mm female receptacle and ending at original 2.1/5.5mm female receptacle, 12v rocker switch starting with standard 2.1/5.5mm male plug and ending with female plug of same size, then lastly the 2nd homemade cable consisting of original 2.1/5.5mm male plug and ending with my soldered on 3.3/5.5mm male plug - mixer 12v receptacle end of the chain.

1.JPG

Now some close ups... 1) the OEM 2 pin IEC which plugs into the DC adapter, which is in turn wired to the standard 3.3/5.5mm male plug that should plug into the back of the mixer:
2.JPG

2: The male DC plug from above plugs into this cable I had to make - a female 3.3/5.5mm receptacle (pictured) - which is soldered onto what was originally the male end of a 2.1/5.5mm DC extension cable. This cable ends in the standard 2.1/5.5mm female end that was on there already.
3.JPG

3: The rocker switch - the originally 2.1/5.5mm female end that I left on the previous cable plugs into the male plug end of this switch (sorry I accidentally took a picture of the female end though)
4.JPG

4: Lastly the female end of the above rocker switch plugs into the 2nd homemade cable below - I left the original 2.1/5.5mm male plug that was on there; the female end of the rocker switch plugs into it. Then on the other end I soldered a 3.3/5.5mm male plug - this is what now plugs into the back of the mixer - it's the 2nd connector down in the pic:
5.JPG

For comparison, this is the length of the OEM 12v PSU cable (top), compared to the combined cables I've had to put/plug/solder together to make this what I thought would be feasible (bottom) - metre stick for scale:
IMG_2198.JPG

Is it possible that seen as I've essentially tripled the length of the cable running the DC current from the OEM PSU box, it's basically created way too much resistance in the cable and dropped way too much power by the time it gets to the mixer for it to sufficiently keep the mixer turned on?

I've now realised the length of the OEM 12v cable is just long enough that I could chop it in half and solder the rocker switch into the middle of it. Then it would be long enough to go through the back of the table, round the to the underside of a shelf in the front where the rocker switch is in easy reach, then back round to the rear and up into the top compartment to plug into the mixer. However I'm a bit hesitant to chop the OEM PSU cable in half-also somewhat put off by the fact I did all this and it doesn't even work how I'd planned haha. That would also mean I'd have to fix the ugly PSU box onto the back of the desk somehow - velcro possibly - though the desk has a nice finish on the wood so I'm reluctant to stick anything in plain sight to it.
 

Yaakov

Joined Jan 27, 2019
3,482
I don’t think the cable length is an issue here. My first move would be to confirm all connections made by soldering on connectors are as expected. This would include resistance, polarity, and isolation (no shorts).

It is a necessary first step in troubleshooting because the symptoms you describe don’t “make sense” and the only (initially) sensible place to look is where you’ve made connections yourself.

You can start with a DMM using continuity mode, and “ohm out” each expected path, and each unexpected path (shorts, reversals, etc.). Once you’ve eliminated those possibilities, we can look for other explanations, but one thing at a time.
 

Thread Starter

manlikemike2019

Joined Apr 6, 2019
12
Ah ok, thanks-I'll have to go get a multimeter - will a cheap one do the job OK?

How do you mean 'ohm out'? Like see which part of the connector (barrel or pin) is carrying the negative and positive?

To be fair when I soldered them on, I used the red as the positive, as I thought that's the standard for these type of electrical cables, no?

How exactly would the solder affect the resistance, polarity and isolation? I was careful to make sure the positive and negatives were cleanly soldered on, not touching each other or anything else...
 

Yaakov

Joined Jan 27, 2019
3,482
Ah ok, thanks-I'll have to go get a multimeter - will a cheap one do the job OK?
A cheap meter is OK, but the cheapest one is probably not. If you are going cheap, try to find one that doesn't measure Amps, and doesn't have a transistor tester built it. Do get one with a continuity mode (beeper). It might be hard to find one that fits this description, but for cheap, that's best.

How do you mean 'ohm out'? Like see which part of the connector (barrel or pin) is carrying the negative and positive?
"Ohm out" is technician slang for checking continuity and resistance. By testing each wire from connector to connector, and noting it's resistance (in Ohms), you can confirm the proper connections are made and that they are electrically good.

To be fair when I soldered them on, I used the red as the positive, as I thought that's the standard for these type of electrical cables, no?

How exactly would the solder affect the resistance, polarity and isolation? I was careful to make sure the positive and negatives were cleanly soldered on, not touching each other or anything else...
By convention, this is correct. And, according to the symptoms it is unlikely (though not impossible) that you have confuse polarity.

The solder would not affect resistance or isolation, but your soldering job could. A bad solder joint would be partially conductive, and a soldier bridge could connect things that should be connected. The point of confirming these things is a general practice. You have an output (the AC from the wall, and the DC from the supply). Always start with checking that path for integrity.

"Is it plugged in?" and "Is it turned on?" are two questions that solve a lot more technical problems than are reasonable. This is a variation on that, "is is connected to power?"
 
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