Unbalanced to balanced

[calorgas]

Quick question for people with a bit of experience of unbalanced & balanced connections:

Can I connect the unbalanced output of my preamp to the balanced input of an active monitor without any issues?

I think I'll be ok as the manual for the monitors states....

If the source has an unbalanced output, a single conductor screened cable can be used as follows: Signal and ground (screen) wired as normal at the source connector; at the XLR end, the signal should be connected to pin 2, and the screen to pins 1 AND 3

...but I was hoping for some extra reassurance

I have a pair of studio rca to xlr cables on order, so would you expect them to be connected as described by the manual by default? Obviously I can check before I use them, but wondered if it's possible or likely that they may require alteration......

 

[Julf]

Can I connect the unbalanced output of my preamp to the balanced input of an active monitor without any issues?

Yes, no problem.

I have a pair of studio rca to xlr cables on order, so would you expect them to be connected as described by the manual by default? Obviously I can check before I use them, but wondered if it's possible or likely that they may require alteration......

There are two ways to do the cable. What you quote is for a single conductor (+ screen) cable. You are actually better off with a 2-conductor (+ screen) balanced cable, making the connection balanced all the way from the RCA end, but both will work just fine.

 

[calorgas]

Great, thanks Julf.

I've got a basic looking 'Stagg' rca -> xlr cable on the way which should get me started then, but I might look at your other recommendation if I'm generally happy with how it all performs in my room.

Actually while I'm at it.....

You are actually better off with a 2-conductor (+ screen) balanced cable, making the connection balanced all the way from the RCA end,

Is this something I can buy 'off the shelf', or would I need to have this made up?

 

[Julf]

Is this something I can buy 'off the shelf', or would I need to have this made up?

Some ready-made RCA-to-XLR cables are 2+1-conductor balanced ones, others are 1+1 unbalanced. Unless they publish the wiring diagram, pretty much the only way to find out is to open up one of the connectors.

 

[linnfomaniac83]

Some ready-made RCA-to-XLR cables are 2+1-conductor balanced ones, others are 1+1 unbalanced. Unless they publish the wiring diagram, pretty much the only way to find out is to open up one of the connectors.

All of the ones I've ever brought, stagg included (albeit with 6.35 T/S jack to XLR) have been of the 2+1 conductor variety, it's probably cheaper and easier for the cable manufacturers to use the one variety of cable. Those stagg cables are alright too, I've quite a few of them in my hire stock and they have proven to be durable, more durable than some of the more expensive brands.

 

[Julf]

All of the ones I've ever brought, stagg included (albeit with 6.35 T/S jack to XLR) have been of the 2+1 conductor variety, it's probably cheaper and easier for the cable manufacturers to use the one variety of cable.

And it is really the right way to do that. Unfortunately I have come across too many 1+1 ones, but then again, I have used far too many cheap no-brand cables...

 

[Cesare]

Yes, no problem.



There are two ways to do the cable. What you quote is for a single conductor (+ screen) cable. You are actually better off with a 2-conductor (+ screen) balanced cable, making the connection balanced all the way from the RCA end, but both will work just fine.

You know, i'm a little confused as to what you are trying to say here.

My understanding is that a typical XLR cable has 2 wires, and a earth mesh (like a coax cable). The mesh is connected to pin 1 (ground) and to the plug itself (so ground and earth are shared) whilst the 2 wires are connected to the other two pins, where the signal is actually sent.

Now with a 2 wire cable, i'm guessing you connect the -ve connector to ground along with the earth at the RCA end, and the +ve pin to the +ve at the RCA end (pin 2). With a 1 wire cable, you'd have to connect -ve (pin 3) to earth at the XLR end. Is this the difference that you are referring to?

 

[linnfomaniac83]

And it is really the right way to do that. Unfortunately I have come across too many 1+1 ones, but then again, I have used far too many cheap no-brand cables...

I tend to use klotz cables or when I can be arsed (not often) make them up using VanDamme cable and Neutrik plugs, I don't let those out of my sight though so will only use them in a system that I'm supervising.

I've used Livewire (Proel) and Piranha cables and had a fairly high failure rate on them. The Stagg cables are cheaper than both and have been pretty good, I've not had one fail yet. I've not had any 1+ screen cables (with an XLR termination) but then I'm way too suspicious of unbranded cables. I got the Stagg cables at the BPM show in Birmingham and did check their construction first.

 

[linnfomaniac83]

You know, i'm a little confused as to what you are trying to say here.

My understanding is that a typical XLR cable has 2 wires, and a earth mesh (like a coax cable). The mesh is connected to pin 1 (ground) and to the plug itself (so ground and earth are shared) whilst the 2 wires are connected to the other two pins, where the signal is actually sent.

Now with a 2 wire cable, i'm guessing you connect the -ve connector to ground along with the earth at the RCA end, and the +ve pin to the +ve at the RCA end (pin 2). With a 1 wire cable, you'd have to connect -ve (pin 3) to earth at the XLR end. Is this the difference that you are referring to?

That's right, you short -ve to ground within the XLR plug if you have a 1+ screen cable.

 

[ChrisPa]

The alternative is to use an RCA to xlr adapter at the source end and then​ use a standard xlr cable (of your choice).

Overall this would be my recommendation.
You know your cables are wired as expected & they can be reused with an xlr source.
Your adapters can be reused with another RCA source

PS. Assuming you've got room behind the source for the depth of the adapters

 

[zippy]

Isn't the unbalanced output from the pre likely to be lower voltage than a balanced output? If so it follows that you're going to need to set the volume control higher.
Not that it matters too much, but for those fussy about such things, it does introduce a bit of a mismatch.

 

[linnfomaniac83]

Isn't the unbalanced output from the pre likely to be lower voltage than a balanced output? If so it follows that you're going to need to set the volume control higher.
Not that it matters too much, but for those fussy about such things, it does introduce a bit of a mismatch.

Yes it will be but the monitor should have adjustment for that (most pro monitors do).

 

[Julf]

Now with a 2 wire cable, i'm guessing you connect the -ve connector to ground along with the earth at the RCA end, and the +ve pin to the +ve at the RCA end (pin 2). With a 1 wire cable, you'd have to connect -ve (pin 3) to earth at the XLR end. Is this the difference that you are referring to?

Yes.

 

[calorgas]

Brilliant, thanks guys that's all really useful info.

 

[HarryCrumb]

Dave, I hope you don’t mind me resurrecting an old thread of yours but I’m trying to do the same thing, just the other way round. I’m hoping @Julf or @linnfomaniac83 can reassure me on this. I want to go from balanced female XLR output > unbalanced RCA phono input. I was advised to follow this Rane document;

https://www.ranecommercial.com/kb_article.php?article=2107

Looking at the wiring diagram about half way down (The Last Best Way To Do It) my situation seems to call for no.4 diagram which is;
Pin 2 hot > rca tip
Pin 1 shield > rca sleeve

I made a 4m cable up to that spec, using 2core shielded and neutrik ends, and set that up today and there was noise on the signal. It’s not affected by volume. The next best looking option for me on that chart is;
Pin 2 hot > rca tip
Pin 3 cold > rca sleeve
Pin 1 shield/short to pin 3 > rca sleeve

I’m going to have a go at that tomorrow but I would appreciate any help as I thought diagram 4 was the right one. The cable was made well and tested with a meter so I don’t think that was the problem.

 

[HarryCrumb]

I re-terminated the cables as;

Hot > pin 2
Cold > pin 3
Shied > pin 1

Hot > Tip
Cold + Shield > Sleeve

No noise at all, clean as a whistle. I know I'm probably loosing some dB's but the volume dial is only slightly further up so it's all good!

 

[s1h1]

Diagram 6 is the usual way it's done, unless the manufacturer specifically warns about shorting out one of the signal pins.

 

[Dougal]

This is probably a very stupid question:

Imagine you have a CD player with RCA outs, and an amp with RCA ins and balanced XLR inputs. Is the best connection going to be RCA to RCA, or does it make any sense going from the RCA outs of the player to the XLR ins of the amp via an adapter? Or would that potentially lead to a worse result than RCA to RCA?

Any advice is welcome.

 

[hifinutt]

adaptors can degrade the sound , stick with rca to rca . i can`t see any advantage with rca to xlr with adaptor

 

[brab]

This is probably a very stupid question:

Imagine you have a CD player with RCA outs, and an amp with RCA ins and balanced XLR inputs. Is the best connection going to be RCA to RCA, or does it make any sense going from the RCA outs of the player to the XLR ins of the amp via an adapter? Or would that potentially lead to a worse result than RCA to RCA?

Any advice is welcome.

Digital guru, John Westlake, wrote somewhere that there was some benefit going from rca to XLR vs rca to rca; however, he was talking specifically about connecting two of his pieces, so I don't know if the advantage generalizes to other pairings. If you want to try, reasonably priced rca to xlr cables are available, e.g. Monoprice (2 conductor) or Cable Matters (1 conductor). I use both interchangeably and they work fine, no noise or other problems.