Wiring XLR connectors from RCAs

[RideTheCrash]

Started from this thread:
http://www.homerecording.com/bbs/sho...d.php?t=185197

Alright, so I want to take my snake which is 1/4" to male RCA and chop off the RCA to replace it with a XLR (only two cables from the snake though). I have done some searching online and am not totally sure on some things, so if someone could clear this up, it'd be cool:

In another forum someone said:
Pin 2 > RCA tip
Pin 3> RCA shield (ground)
Pin 1> not connected

But, on other sites I have seen pins 1 and 3 get wired to the ground, not just pin 3.

[James HE]

Check out this site.

http://www.vandenhul.com/artpap/wiring.htm

[RideTheCrash]

Okay this page:
http://www.vandenhul.com/artpap/wiring17.htm

Is pin one not connected to anything? I can't tell if that brown line is supposed to be a cable or something. And this page: http://www.vandenhul.com/artpap/wiring18.htm, says there is two kinds of cables (single and twin). I'm not sure what my cabling is, but is my idea still doable? It's just confusing because I figure "okay, this was *originally* male 1/4" to male RCA...so what wires would be in the cable when I cut it off so that I could make it 1/4" to XLR. Excellent site though.

I'm trying to get my head around this, my apologies.

[SRR]

Why don't you save the snake from the choping up part, and just buy rca to XLR adaptors.

[RideTheCrash]

Because I can never find any around here. But I guess the better reason is, because the snake is cheap and somehow the second cable I want to chop, had it's connector broken off. The whole metal piece came out of the plastic molding and I have no idea how it was even connected in the first place. So instead of chopping that off and putting on a new RCA jack, I might as well chop them off and connect XLRs.

[RideTheCrash]

Anyone?

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[mshilarious]

If you have an RCA-RCA cable right now, it's very highly likely that it is single conductor + shield. You are never going to be able to wire this for balanced use . The site linked, the first diagram the signal goes to pin 2 and the shield to pin 1. That gives you an unbalanced connector, it will work OK for connecting line level gear (albeit unbalanced). If you get too much hum, well then you'll need to get a balanced (2 conductor) cable.

[RideTheCrash]

The cable is currently 1/4" to RCA. My gear is all pretty much unbalanced, so I"m not too concerned about whether it is balanced or not, though the XLR inputs on the Delta *are* balanced. I'm not sure whether it being 1/4" to RCA would mean it has two conductor cables or not though. The cable is just running from a mixer to a soundcard, so it's all line level.

[karyoker]

Tell me what you are hooking up going into the snake and whats coming out and I'll give you a hookup pinout.....

[RideTheCrash]

Well for this particular snake, it is used as direct outs for each channel on my mixer (well, the first 8 channels on my mixer). So the 1/4" end is plugged halfway into the insert out (as to create the direct out effect) and the other end is hooked up the Delta 1010lt soundcard. The first two inputs on the Delta are XLR, the rest are female RCA. The first two XLR inputs are what I'm looking at, so I want two of the snake cables to be female XLR (instead of RCA) so it'll connect the male XLR inputs on the Delta.

[RideTheCrash]

bump

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[SRR]

Pin 2 of the XLR should be hot, so that should be tied to the center of the RCA cable. Then pin 1 and 3 should be tied together and that of course would go to the shield of the cable, IMVHO.

[Ford Van]

Originally Posted by RideTheCrash

Well for this particular snake, it is used as direct outs for each channel on my mixer (well, the first 8 channels on my mixer). So the 1/4" end is plugged halfway into the insert out (as to create the direct out effect) and the other end is hooked up the Delta 1010lt soundcard. The first two inputs on the Delta are XLR, the rest are female RCA. The first two XLR inputs are what I'm looking at, so I want two of the snake cables to be female XLR (instead of RCA) so it'll connect the male XLR inputs on the Delta.

Okay. One problem here.

I believe that on the Delta 1010LT, those two XLR inputs go to a mic preamps. I don't think they can be line level inputs at all.

So, you don't WANT the insert outs (which are LINE LEVEL outputs) from your console to go to those XLRs (which are mic preamp inputs) at all! Trust me, it would be a hassle and most likely will not sound so good.

You have 8 line inputs on the 1010LT. Do you think you really NEED two more inputs? If so, just use the mic preamps built into the 1010LT and call it good.

[SRR]

Hehehe, ford those XLR inputs CAN be switched to line level. On the card itself there are jumpers for each of the XLR ins, you can change them seperately.

[RideTheCrash]

Yes, SRR is correct. There is two mic level and two line level setting that can be set with the jumpers, which I have done. Also, the first two are XLRs, are the other 6 are line level RCAs connections. So without the first two, I'd only have 6 line level inputs. The extra 2 inputs/outputs are if you want to use the optical/MIDI stuff I think, which I have no use for.

[Ford Van]

Simple then. RCA tip to Pin 2. RCA sleeve to Pin 1. Don't run anything to pin 3.

[RideTheCrash]

Okay. Is there any reason everyone says a different way as to how to wire it? Or does it matter?

[Ford Van]

The extra 2 I/O is via the S/PDIF connections.

Sorry for the confusion. I should have read the specs completely before I spoke up!

[RideTheCrash]

Okay, I've attached some pictures of the RCA ends of the snake. The gray one is the busted one and the black one is the other one I want to solder an XLR connecter to. I apologize for the washout in some of the pics, we have a new camera which has crazy flash, hence the red tint in the one picture (me trying to diffuse it).

So I posted this because I'm a bit confused. The RCA bit that came out looks like it has one solder connection on the end (broken off of course) and the cable it came from is just plastic casing, I don't see anything. I haven't cut the ends off yet of course, but it makes me wonder what will be there judging from what I see now. I'm assuming there has be two wires for a tip and sleeve in there though. Just wondering...

[MOFO Pro]

You'll probably find a center conducter with a braid shield around it...

[RideTheCrash]

Hmm, and is the wiring going to be any different than what was suggested if that is the case?

[Gilliland]

The reason why you are getting so many different answers is because there is no "correct" way to do what you are attempting. Here's a Rane Note that covers these connections:

http://www.rane.com/note110.html

According to the note, the right way to make this connection is via an isolating transformer. If that can't be achieved, the next best way is #17 in that document, which in your case isn't possible because your snake doesn't use two-wire shielded cable. The best you can hope to do is to connect pin 2 to the center connector, and then connect the shield to either pin 3, pin 1, or both. You may have to try it to see which works best with your particular equipment (with hum being the principal obstacle to overcome).

Your shielded one-wire cable should never be used in this way, at least according to Rane. Interestingly, Rane seems to feel that it is OK to use a single center conductor when the source (output) is balanced, but not when the target (input) is balanced. And in those cases, the question of how to connect the shield is dependent on the topology of the source circuit. But that's not your scenario anyway.

[RideTheCrash]

Okay, since I'm relatively stupid when it comes to understanding most of that, I'm thinking again...

Not sure what you meant by #17, wouldn't it be #13, because I'm going from a 1/4" TS to a male RCA (as of now), but it's the RCA I want to change to XLR.

If what you just posted is the case, I don't want to take too many chances. Is it even possible to solder the RCA jack back into the casing? I think I might try to track down an RCA>XLR adapter if I can solder it back on then...

[Gilliland]

Originally Posted by RideTheCrash

Not sure what you meant by #17, wouldn't it be #13, because I'm going from a 1/4" TS to a male RCA (as of now), but it's the RCA I want to change to XLR.

You're probably right. I didn't look that carefully at your configuration. Since it was an RCA on one end, I assumed that it was an RCA on the other. Still, it doesn't really make any difference - the two are exactly the same except for the connector at the unbalanced source end. For our purposes, there is no difference whatsoever between an RCA plug and a quarter-inch Tip-Sleeve connector.

I have no idea whether or not you can put the RCA plug back together, but it should be easy enough to replace it completely if you need to.

Just keep in mind that if you "track down an RCA>XLR adapter", it will have all the same issues - unless it includes a transformer to balance the signal. Nonetheless, we've all done these kinds of connections from time to time - you'll probably be able to make it work.

[RideTheCrash]

Now, since my cable appears to not be two wires, there will still be a wire with a shield wire to solder onto the pins of the XLR? So there is two wires to be used. I'm just confused, because it's one wire, but then how to connect to pin 2 and then to either 1 or 3?

But anyway, shouldn't an RCA to XLR adapter have an isolation transformer in it for it work? I'm not even sure what one is. I look at it this way:

What I did before, which was annoying, was I had the RCA male connected to an adapter which went to a 1/4" male, which went into an adapter which went to a female XLR, thus allowing me to connect the XLR male on the soundcard. This worked, but the connectors were bulky and I think were part of the reason the one RCA busted off (got crushed).