Replacement PSU for M Patch 2 Monitor Controller

[2pods]

Hope this is in the right place, but anyway the mods will move it if not...

Switched the gear on today (individually as usual, in case of overload) when I noticed no lights on my wee M-Patch 2 monitor controller

It's a few years old, and came with a Euro 2 pin plug which I've been using with 2 to 3pin fused adapter. I've tried the 2 to 3 pin adaptor with my razor cleaning wotsit, and that works OK, so I'm assuming it's the actual adaptor.

It states on the back it's an "AC/DC Class II Transformer, Input 230v ~ 50Hz, Output 15v DC 200mA, model D35-15-200"
Not quite sure which bit of the input barrel to measure, but the diameter is big enough to nearly fit the width of one of 2 pins in.
It also seems to be middle of the barrel positive and the outside negative.

Any chance of a link to a (preferably UK) replacement ?

Thanks

[Drew Stephenson]

Vexingly you'll actually need the internal and the external diameter of the plug.
If you've used a multi-adaptor at any point before you might have a selection of plugs around to try. Otherwise an email to JBL might be your best bet.
Once you've got that then any UK power supply that'll deliver at least 200mA at 15v DC will do the job.

[Hugh Robjohns]

It would help if you could identify the specific coaxial plug size -- there are a few variations of pin and outer diameters that all look quite similar.

However, finding a 15V DC regulated supply capable of delivering 500mA (or more) isn't difficult. (The JBL user-manual graphics suggest it requires 500mA, BTW...)

Here's a possibility:

https://www.acadaptorsrus.co.uk/replace ... y-150-050/

It's just a question of whether that plug fits...

[BigRedX]

I've had a look at a review of this device (it's in the SOS archive) and the main signal path is completely passive, the PSU only being required for the status LEDs and the headphone amp, so maybe the unit itself has died.

I'd get out a multimeter and check what's happening at the low voltage end of PSU before going any further.

[porthoss78]

Hi,

If it does turn out to be the PSU, give these a call/email:

https://myvolts.co.uk

They just need some information about the existing PSU and a photo of the PSU socket (or they did with my PSU replacement for an old Korg).

Hope that helps
J

[Martin Walker]

I've had a look at a review of this device (it's in the SOS archive) and the main signal path is completely passive, the PSU only being required for the status LEDs and the headphone amp, so maybe the unit itself has died.

I'd get out a multimeter and check what's happening at the low voltage end of PSU before going any further.

+1 to that info - I wrote the SOS review, and the signal path is indeed totally passive, so your M-Patch 2 will carry on working regardless of its current lack of LED indicators and headphone amp.

Martin

[2pods]

Thanks everyone for your replies.

I should be able to work this out for myself, but I'm having a hard time taking things like electrical formulae in owing to an illness, So I thought I would consult the Gods directly

I do have some multi barrel adaptors laying about. What concerned me was that nearly everything I was looking at seemed to be more than 200mA. Some being 500mA, some even 2A. So I didn't want to fry the poor thing, as it's very useful.

I seem to remember something about that figure was "at least" but I just can't remember. So better safe than sorry.

[BigRedX]

Unless you are using this primarily for the headphone output it should still be working even though none of the LEDs light up as the signal path for the two monitor outputs is completely passive. If you're not getting anything from the monitors then the unit itself is dead and a replacement PSU won't help.

Were you able to check the PSU with a multimeter?

If you do need a replacement PSU then anything delivering 15DC (make sure it's DC) with a minimum of 200mA and the right polarity plug (and double check this) should do the trick.

[Wonks]

Indeed. The milliamp rating of a PSU is the maximum current that can be drawn from it. Depending on the PSU design, you may need to draw maybe 5-10% of its rating before you get a fully voltage regulated supply, so it's best not to use a single 7mA pedal with a 1A/1000mA PSU if you can help it.

But a unit that draws say 180mA from a 15vDC will draw 180mA from a 200mA PSU, 180mA from a 500mA PSU and 180mA from a 1000mA PSU.

You only get problems once you try and draw more that the PSU rating, so a 180mA unit fed from a 100mA PSU is very unlikely to work at all. As you start to exceed exceed the PSU's mA rating, the supplied voltage first drops off, and then the PSU gets hotter and hotter. If an internal fuse (if there is one) doesn't blow, then it can really overheat and possibly catch fire or release the magic smoke.

Think of it a bit like like a 230v mains socket. It can provide up to 13A, so you can happily plug in a phone charger drawing almost nothing, or a 3kW electric fire, and all is fine. You only get problems once you exceed 13A.

Likewise with a PSU, you only get problems (except possibly from very light loading when the supplied voltage can drift up quite high), once the PSU's mA rating is exceeded.

[Martin Walker]

Unless you are using this primarily for the headphone output it should still be working even though none of the LEDs light up as the signal path for the two monitor outputs is completely passive. If you're not getting anything from the monitors then the unit itself is dead and a replacement PSU won't help.

Were you able to check the PSU with a multimeter?

If you do need a replacement PSU then anything delivering 15DC (make sure it's DC) with a minimum of 200mA and the right polarity plug (and double check this) should do the trick.

I've just decided not to be so lazy and pulled out gear so I could laay my hands on my own M-Patch 2 PSU, and that reads 12V DC @500ma, centre positive. This simply means that the voltage isn't too critical (as you'd expect given that it's only supplying the headphone amp and the LEDs). In fact, it states on some M-Patch 2's Power DC 12-16V.

EDIT: I've now also confirmed that it's a 2.1mm output plug you need.

Hope this helps!

Martin

[Drew Stephenson]

Unless you are using this primarily for the headphone output it should still be working even though none of the LEDs light up as the signal path for the two monitor outputs is completely passive. If you're not getting anything from the monitors then the unit itself is dead and a replacement PSU won't help.

Were you able to check the PSU with a multimeter?

If you do need a replacement PSU then anything delivering 15DC (make sure it's DC) with a minimum of 200mA and the right polarity plug (and double check this) should do the trick.

I've just decided not to be so lazy and pulled out gear so I could laay my hands on my own M-Patch 2 PSU, and that reads 12V DC @500ma, centre positive. This simply means that the voltage isn't too critical (as you'd expect given that it's only supplying the headphone amp and the LEDs). In fact, it states on some M-Patch 2's Power DC 12-16V.

EDIT: I've now also confirmed that it's a 2.1mm output plug you need.

Hope this helps!

Martin

2.1 is the internal barrel measurement, have we established the outer?

[Martin Walker]

2.1 is the internal barrel measurement, have we established the outer?

The outer diameter is 5.5mm for both the 2.1 and the 2.5mm inner diameter versions.

The only other possible difference is the exposed length of the 5.5mm barrel - in the majority of cases this really doesn't matter, although occasionally if the PSU socket in your gear item is recessed, the plastic surround of the plug is somewhat bulky and the diameter of the hole in the gear chassis is on the snug sound you may find you need a longer length of 'bare 5.5mm barrel' to get the plug fully home to make positive contact. I've only ever had that happen with one device though

Standard 10mm length 5.5mm x 2.1mm plug (as fitted to most PSUs):



Longer 14mm length 5.5mm x 2.1mm plug:



Martin

[Drew Stephenson]

[2pods]

Thanks for everyone's help. I appreciate it.

Explanation was crystal clear Wonks, and I might have known Martin W would still have had his

So, the one in the link is out, as the barrel is 5.5mm ?
https://www.acadaptorsrus.co.uk/replace ... y-150-050/

I'm borrowing a Multimeter today. If the news is bad, I'll look for something with the right specs.

[Wonks]

As Martin mentioned ‘most PSUs’, then I’m pretty sure he meant 5.5mm, not 5mm. 5.0mm is certainly not ‘usual’, and is going to be pretty rare.

[Hugh Robjohns]

Most of the ones I've used are 5.5mm for the outer barrel diameter.

[Martin Walker]

As Martin mentioned ‘most PSUs’, then I’m pretty sure he meant 5.5mm, not 5mm. 5.0mm is certainly not ‘usual’, and is going to be pretty rare.

Whoops sorry, I DID mean 5.5mm - have amended my post to avoid further confusion

Martin

[Dynamic Mike]

Hi,

If it does turn out to be the PSU, give these a call/email:

https://myvolts.co.uk

They just need some information about the existing PSU and a photo of the PSU socket (or they did with my PSU replacement for an old Korg).

Hope that helps
J

I've used these guys and happy to second the recommendation. Not the quickest service but good quality products and great communication.

[2pods]

Thanks for the info.

Nice to know it's not just me who gets a bit confused

Still awaiting Multimeter

[2pods]

I seemed to have solved my problem.

Bad news: I have an old one disk WD My Cloud which bricked it self yesterday.

Good news: I took a look at the adapter, and it was well within the specs. So all is well, and I have my lights and HPhone socket back.

Thanks for everyones' help

[Hugh Robjohns]

[Martin Walker]

And a from me as well.

Saved you at least a tenner anyway

Martin