MUFF WIGGLER Forum Index
 FAQ & Terms of UseFAQ & Terms Of Use   Wiggler RadioMW Radio   Muff Wiggler TwitterTwitter   Support the site @ PatreonPatreon 
 SearchSearch   RegisterSign up   Log inLog in 
WIGGLING 'LITE' IN GUEST MODE

using xlr for external psu.
MUFF WIGGLER Forum Index -> Music Tech DIY  
Author using xlr for external psu.
berfmurret
can anybody think of any reasons i can't use xlr chassis mount connectors and a mic cable to get power from an external PSU enclosure to the rack where modules are mounted?

i am having trouble finding some other 3 pin solution that doesn't cost an arm and a leg. i can get connectors for a couple of bucks a piece and an xlr cable for not much more.
the bad producer
I can only think of the reasons that I was given when I asked the same question on a forum a couple of years back - That 'someone' would plug their expensive audio 'thing' into my PSU input/output and blow up their 'thing'...

Basically I got a group bollocking for even thinking upon the idea... my POV is that the only person plugging shit into my stuff is me, so I went with it, much cheaper...

I use proper 3-core mains cable for the leads, cheaper again than mic cable..
BugBrand
I like to recommend these from Futurlec:

XLR-Mic Connectors
- partly 'cos I wouldn't want to mix XLR standards with power..
These are well priced, nice in use and reliable.

Mic cable used as power cable? Could work for small currents, but it ain't designed for such purposes -- if you're powering a whole rack then you'd certainly want something more suited to the current draw.
(in theory if you're taking too much current down them then they could melt (the two 'signal' wires of the mic cable) - in practice I dunno if that'd actually happen, but don't do it anyways 'cos it ain't right!!)
TrashWaveform
I am an industrial tech and I seen the XLR jacked used for this purpose for a 120v circuit. The cable however was not a mic cable, it looked custom using 14-16 gauge wire. And the end of the cable was obviously female instead so you wouldn't have the risk of shock with it plugged in an outlet but not into the machine. As long as you can find a cable with decent insulation on the individual wires it shouldn't be an issue. However chances of finding a mic cable designed with the use of carrying a current like that is kinda unlikely especially with cheap cables.

I recommend using the normal CPU style standard. Lots of parts for this and its cheap. But I think if you used only the jacks and used the normal 3 prong cable with the jacks as XLRs it should work fine as I see this used without issue all the time on some machines that run 24/7.
berfmurret
that is perfect, bug!

i knew what i was looking for and not finding and that is it!! i just couldn't find something at a price like that..

much thanks!
mono-poly
Use a connector they use for shortwave radio mic's.
I use them on my Modcan and Eurorack and racked some power ones in a separate 19 inch frame.
NV
You can use whatever connectors you want for interfacing power, as long as there's a reliable electrical connection that can handle the current. In other words you probably don't want to run 10 amps through a USB connection.

The main concern would be the cabling. I wouldn't use a microphone cable to run a large amount of power, but there's no reason why you couldn't just use a few 16-gauge wires twisted together. You can buy cabling that would work perfectly for this from any store like Home Depot - they sell 300-volt 3-conductor wire for power tools for about $0.50 a foot that would be able to carry both +/- voltages and ground without any worry. Solder it to your plugs of choice, make it pretty, and you're set.
BananaPlug
XLR connectors have been used for DC power in professional video equipment for decades. They just don't use 3 pin. If you use 4 or 5 pin XLR you're not going to blow up any audio gear and they are a very nice connector for the job.

I used XLR4 on this 12v supply for my Serge.
JohnLRice
In addition to the other fine suggestions I know some people have used the big Speakon connectors for modular power.



http://www.neutrik.com/fl/en/audio/203_324141/Speakon%C2%AE_Lockable_L oudspeaker_Connector_group.aspx

What is nice about them is that they are designed to handle a reasonable amount of power transfer and you can use large cable easily (and you can get pre made cables so you can just mount you panel connectors, but a cable, plug and play. Although, I don't know if there are premade cables in short enough lengths for you.)

The down side is that the connectors are large and will stick out of the back of your rack a fair bit. (there is at least one right angle connector available though)
wetterberg
and the problem with speakons is the same as with regular XLR; Also used for audio...

The ones linked by the always sage Bugsie-boy are great for power, I think in part because they give you a nice warm feeling when connecting; lots of quality to the system I feel.
DGTom
+(another)1 for the ones Tom Bugs linked.

I use the 4 pin for bipolar & the 2 pin for 9V stuff.

The other cool thing is you can also get male / female connectors & panel mounts, so you can 'key' stuff & make extension cables for those times you something longer than usual.

& they screw together & feel mad hardcore & industrial... YO!
bwhittington
JohnLRice wrote:
In addition to the other fine suggestions I know some people have used the big Speakon connectors for modular power.


Personally, I'd be wary of using Speakon connectors. I use them for my PA speakers, and it seems like I spend half my life repairing them. Whoever designed a big, durable, locking connector with little screw terminals for the wires as the weak link was an idiot, as far as I'm concerned. For electrical use, I'd be very concerned about arcing as those connections come loose.

Cheers,
Brian
chinard
i look at it this way.

if anybody is plugging in my modular and i'm not around they DESERVE to get their audio gear fried MY ASS IS BLEEDING Dead Banana
goiks
BananaPlug wrote:
XLR connectors have been used for DC power in professional video equipment for decades. They just don't use 3 pin. If you use 4 or 5 pin XLR you're not going to blow up any audio gear and they are a very nice connector for the job.

I used XLR4 on this 12v supply for my Serge.


+1 for 4 pin xlrs. i'm going this route with one power supply cabinet for several smallish cabinets.
daverj
berfmurret wrote:
.... to get power from an external PSU enclosure to the rack where modules are mounted?


How long of a cable are you thinking of doing?

If it's a foot or two, that's not a problem. If you're thinking of running a long distance then you'll lose regulation and add noise.
Waz
Why not IEC?
DGTom
I think for the same reason 3 pin XLRs are not a good idea. Pretty sure we're talking about bi-polar, post modular PSU cables / connections here. Having an IEC on the side of your synth where you should be putting +/-15V would be even more risky - end up with mains direct into the modules!
megaohm
berfmurret wrote:
can anybody think of any reasons i can't use xlr chassis mount connectors and a mic cable to get power from an external PSU enclosure to the rack where modules are mounted?


Mic cable wire is too small.

I use XLR connectors to power my cabs. I used 18AWG wire but I would have preferred 14-16AWG. I recall a data sheet specify that 18AWG is the largest wire the XLR plug could accommodate. That said, it works fine.

The next PSU will use banana plugs and jacks. That's my suggestion.

p.
mono-poly

I use that cb-radio plug for my modulars it works great.
BananaPlug
DGTom wrote:
+(another)1 for the ones Tom Bugs linked.

http://futurlec.com/XLR-MIC.shtml
FYI, that kind of connector is also what you find on Modcan A systems.
mono-poly
You can fit the male ones perfect in the hole on the back off a Cyndustries sixpack!
RetBody
BugBrand wrote:
I like to recommend these from Futurlec:

XLR-Mic Connectors
- partly 'cos I wouldn't want to mix XLR standards with power..
These are well priced, nice in use and reliable.


I've got a Requisite tube limiter that uses those connectors for the external PSU and they carry 240v for the tubes with no troubles, and the screw makes for a rock-solid connection.
ricko
This is an old thread, but for AC (i.e. from external transformers) I really recommend Powercon connectors (the Neutrix design for specifically for power).

Lockable, robust, safe plastic not metal, ground contacts first, no pins sticking out that can short out or make contact.

For AC, especially for mains voltages, the worst thing is a live plug with pins: unsafe. Using a male XLR connector for a power cable connection to some synth is simply not appropriate: if you have to use an XLR connector, make sure the power input socket is the male, and the cable has the female. (And, by the same logic, you use the female socket at a power outlet, if you have to.)
Graham Hinton
ricko wrote:
This is an old thread, but for AC (i.e. from external transformers) I really recommend Powercon connectors (the Neutrix design for specifically for power).


Powercons are mains connectors, so that is a really bad recommendation. You've revived a ten year old thread just to say that?!

Quote:

Using a male XLR connector for a power cable connection to some synth is simply not appropriate: if you have to use an XLR connector, make sure the power input socket is the male, and the cable has the female. (And, by the same logic, you use the female socket at a power outlet, if you have to.)


You never have to use an XLR and it should never be used for mains. There used to be a special XLR-LNE connector for mains (with red plastic insulation), but it was withdrawn after safety regulations tightened.

I have used 4-pin XLRs for DC outlets in the past, but I don't recommend them now and definitely not for over 250mA. You could use them for small peripherals to a case, but not for the main DC inlet. Basically, no audio connector is really suitable for power.

There are several factors that are not being considered here apart from avoiding other conflicting usage. The contact resistance and the size and resistance of wiring are very important factors. Even the extra large Neutrik XLR boot only takes five 18awg wires. If you are powering a case from an external PSU then remote sensing is really needed otherwise you are begging for common impedance problems. That means for a dual PSU you need a minimum of eight pins plus Earth.

The connectors I use and recommend for low voltage DC power now are the ITT Trident series, but I recommend internal mains PSUs because the best, and cheapest, way to get power (up to 2kW) and Earth into a case is via IEC C13/C14 connectors.
The Real MC
Never use the shell for power ground. It is not a reliable connection.

The Moog Liberation used a six pin XLR for low voltage power, but they used the shell for power ground which did not work that well.
MUFF WIGGLER Forum Index -> Music Tech DIY  
Page 1 of 1
Powered by phpBB © phpBB Group