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Gear / Technical Help => Cables => Topic started by: kingtut38 on May 24, 2010, 11:42:59 PM

Title: Going from 3.5 mini stereo to xlr?
Post by: kingtut38 on May 24, 2010, 11:42:59 PM
I know this is probably a dumb question and I'm not an experienced taper really but is there any way to go from a male 3.5 stereo plug to two xlr's.  I've got some small omni condensers that are 3.5 and I want to go out to xlr.  How would one use small electret condensers with a xlr only recorder like the fr2-le?
Title: Re: Going from 3.5 mini stereo to xlr?
Post by: boojum on May 24, 2010, 11:48:22 PM
Electrets require some power, usually not greater than 9 volts DC.  If you get a set of 3.5mm to XLR you will need a battery box between the mics and the recorder which will be accepting the input without phantom power on.

electrect > battery box > 3.5mm to XLR cabling > recorder of choice "mic in" no phantom power.
Title: Re: Going from 3.5 mini stereo to xlr?
Post by: kingtut38 on May 24, 2010, 11:50:18 PM
thanks for the reply. 

Title: Re: Going from 3.5 mini stereo to xlr?
Post by: Nick's Picks on May 25, 2010, 09:01:05 AM
from 3.5mm, you have 3 wires.  + / - (right and left signal) and ground.

the right and left go to pin 2 on the XLRs (one for each...left / right).
the ground goes to pin 1 on BOTH xlrs (one ground source, that being the mesh shielding, can be split or utilize and jumper wire to each of them w/o issue)

the best way to make this is with two individual runs of shielded 2 conductor wire as its hard to split a single wire into two separete runs w/o there being grounding issues, lousy connections...etc.
not that the single wire solution  can't be done, but its far more secure and reliable with two wires.

Other wise...get a piece of 4 conductor shielded wire, like star quad or any other quad config.
use two of  the conducting wires for each channel.  One is signal, one is ground. (4 wires total, two to each XLR)
The downside of this single wire construction is that you will not have shielding for the last few inches where it the Y is (single wire branching off into two leads for the XLR).  But that should not pose any significant problem.
In fact, the stock Studio Projects LSD2 stereo cable does exactly this.  the Y at the end is not shielded.  that mesh is cut back to where they make the split into left / right channels.

As for the XLRs, as I said...the signal goes to pin 2.  the ground connection to pin 1.
leaving pin 3...., which you can "float" (not connected to anything), or ground off of pin1.

I'd leave it floating and empty.  If you experience noise, you can ground it then.  But...I doubt you will have problems.
happy soldering !
Title: Re: Going from 3.5 mini stereo to xlr?
Post by: Todd R on May 25, 2010, 12:25:01 PM
I agree with boojum that you need to pay attention to the specific needs of your mics.  They are unlikely to work without some type of mic powering, and sending 48v phantom mic power will probably fry them. 

It really depends on exactly what your mics need, but if the two omni mics are connected to a single 3.5mm plug, something like the PFA from Naiant might work:

http://www.naiant.com/studiostore/inlinedevices.html

If not, it still might be helpful to discuss this with Jon at Naiant (mshilarious here on ts.com) to see if he can build something that would work with your specific mics needs. 

What nickspicks is proposing might work for going 3.5mm mini out from a preamp to the XLR inputs on a recorder, but it will not address the mic power needs of 3.5mm TRS terminated microphones.
Title: Re: Going from 3.5 mini stereo to xlr?
Post by: Nick's Picks on May 26, 2010, 07:01:26 AM
I was addressing the subject line......

however.., suppose you had a 9v bat box that had XLR inputs (unbalanced). 
I dont see how this wouldn't work in that case ?? 

I'm just thinking about cheap omni caps (Panasonic or equiv) which only require two wires each to run with a 9v.
Also curious as to how this "might not" work when going to 3.5mm > XLR Todd ????
is there another way to do that bridge that i'm missing ?  take the powering out of the equation, and just bringing signal from 3.5mm > XLR ??

I'm considering of all the mics out there terminated w/a 3.5mm that like battery power.  Every SP mic, much of the Core-Sound...Church Audio..etc etc.  the common folks.  All of those rigs are a 3 wire connection for TWO mics...with one of the three being a shared ground.
Even if a BB was in line w/the mics..so they are fed power...you still have a 3.5mm output and lets suppose for the sake of this thread you want that to go into your recording deck with XLR inputs.

The thread..., I thought, was more about bridging the connection than providing a full schematic with power options. 
But.., that is what the poster needs to know first and foremost, as Todd points out.

Good info all around fellas!
Title: Re: Going from 3.5 mini stereo to xlr?
Post by: Todd R on May 26, 2010, 10:26:35 AM
Yeah, the issue at hand really is about how to get power to the mics.  The cabling will need to support that, but the mics will need power unless they have internal battery power.

So your cabling description should work for going out of a preamp to the fr2le recorder or going out of a battery box with a 3.5mm output to the recorder. 

The OP didn't mention a battery box or preamp though, so I'm assuming he only has the mics and the fr2le.  The fr2le can provide phantom power at the XLRs, which I'm guessing without knowing the recorder is 48v.  Again, not knowing the mics, but most small omni mics with 3.5mm connectors are stealth-type electret mics that need ~ 5-9v of plug-in power, not 48v phantom, and the fr2le doesn't supply that voltage on the XLR inputs.  The cabling you mention might be able to pass 48v phantom in some fashion to the mics, but that may well fry them.

Again, we all really need more info from the OP to say for sure, but the PFA phantom power adapters from Naiant may be just what he needs.
Title: Re: Going from 3.5 mini stereo to xlr?
Post by: kingtut38 on May 26, 2010, 03:55:19 PM
Thanks guys for the help.  It looks like the link that Todd posted is gonna be what I need.  I've basically got a pair of church omnis.  I think he calls them "pro binaurals" and I was wondering how to get them into the FR2-LE.  I've learned about the issues involved with this now that I've read your posts.  Since I'm fairly new to portable recording I incorrectly assumed an cabling adapter would work but I hadn't taken power into the equation.  Looks like the Naiant should work ok.
Title: Re: Going from 3.5 mini stereo to xlr?
Post by: jnorman34 on May 26, 2010, 05:44:55 PM
my DPA 4061s are terminated in a stereo mini-plug.  i had Naiant make me a PFA (phantom power adapter) for $75 that has a stereo mini-jack on one end and two std XLRs on the other end.  since the DPAs need about 9v, he put a reducer in the connectors to convert regular 48v phantom power down to 9v.  works like a charm.  of course you do need to be using a regular 48v power source to supply the voltage (mine comes from my lexicon U42s USB interface).
Title: Re: Going from 3.5 mini stereo to xlr?
Post by: rePat on May 27, 2010, 12:01:04 PM
my DPA 4061s are terminated in a stereo mini-plug.  i had Naiant make me a PFA (phantom power adapter) for $75 that has a stereo mini-jack on one end and two std XLRs on the other end.  since the DPAs need about 9v, he put a reducer in the connectors to convert regular 48v phantom power down to 9v.  works like a charm.  of course you do need to be using a regular 48v power source to supply the voltage (mine comes from my lexicon U42s USB interface).

I bought one of these adapters from Sound Pro's a few years ago, in the same price range.

Pat

Edit: Link http://bit.ly/a6U9Ms (http://bit.ly/a6U9Ms)
Title: Re: Going from 3.5 mini stereo to xlr?
Post by: sunjan on May 28, 2010, 08:10:18 AM
my DPA 4061s are terminated in a stereo mini-plug.  i had Naiant make me a PFA (phantom power adapter) for $75 that has a stereo mini-jack on one end and two std XLRs on the other end.  since the DPAs need about 9v, he put a reducer in the connectors to convert regular 48v phantom power down to 9v.  works like a charm.  of course you do need to be using a regular 48v power source to supply the voltage (mine comes from my lexicon U42s USB interface).

I bought one of these adapters from Sound Pro's a few years ago, in the same price range.

Pat

Yup, if you're just looking for a plain cable, SP sells them for $25:
http://www.soundprofessionals.com/cgi-bin/gold/category.cgi?item=SP-XLRM-MINI-2

As a ghetto battery box, you could actually use an old vintage recording walkman, and just pass-thru the signal to benefit from the PIP.

Another option is to ask Chris Church to custom-fit a battery box with dual XLR out.
But looking at the cost, you might as well save yourself the trouble and just pick up a cheap pair of phantom mics. AT853Rx springs to my mind...
Title: Re: Going from 3.5 mini stereo to xlr?
Post by: ArchivalAudio on May 31, 2010, 11:26:40 PM
If your are going to go into a FR2-LE
as line in then you NEED 1/4" either TS or TRS
the XLR ins on the FR2-LE are only (ONLY) mic level in

again if you want to run from a pre or other source that runs at line levels out then you need to use the TS or TRS 1/4" male plugs  in

however if the Battery box is merely powering the mics and sending a mice level in then you will need to go in via the XLR's

back to normal discussions

--Ian
Title: Re: Going from 3.5 mini stereo to xlr?
Post by: willndmb on June 02, 2010, 01:26:08 PM
IF you were going to use the battery box option - you could always go battery box > fr2le via 1/4 line in
Title: Re: Going from 3.5 mini stereo to xlr?
Post by: disco on September 20, 2010, 09:49:27 AM
my DPA 4061s are terminated in a stereo mini-plug.  i had Naiant make me a PFA (phantom power adapter) for $75 that has a stereo mini-jack on one end and two std XLRs on the other end.  since the DPAs need about 9v, he put a reducer in the connectors to convert regular 48v phantom power down to 9v.  works like a charm.  of course you do need to be using a regular 48v power source to supply the voltage (mine comes from my lexicon U42s USB interface).

I bought one of these adapters from Sound Pro's a few years ago, in the same price range.

Pat

Yup, if you're just looking for a plain cable, SP sells them for $25:
http://www.soundprofessionals.com/cgi-bin/gold/category.cgi?item=SP-XLRM-MINI-2

As a ghetto battery box, you could actually use an old vintage recording walkman, and just pass-thru the signal to benefit from the PIP.

Another option is to ask Chris Church to custom-fit a battery box with dual XLR out.
But looking at the cost, you might as well save yourself the trouble and just pick up a cheap pair of phantom mics. AT853Rx springs to my mind...

tgakidis made me a cable that does the same thing except they terminate in mini xlr's. Works great and powers my church mics from my littlebox. Built & arrived within mere days...def the way I'd go so that you know it works