RCA to XLR trouble

[rcstevensonaz]

Then Wiki needs to read Audio Engineering Society Standard AES48, or some of Bill Whitlock's papers.
But then 'chassis ground' is not 'circuit ground'.

But should Pin 1 be connected to the XLR connector's metal tab for an Unbalanced to Balanced cable (as shown in that diagram)?

 

[Speedskater]

For a pro audio portable extension interconnect cable, no. (AES 54)
But for a component to component interconnect, sure in can be and it will give slightly better shielding.

 

[quattro98]

A data point on commercial cables if someone wants to buy ready-made.

I added DIY class D/Hypex Nilai 500 amps for LCR to my system, driven by a Denon 8500 AVR. To get things up and running quickly, I used "Cable Matters Dual RCA to XLR Unbalanced Interconnect Cable" from Amazon. There was audible hum within about 2 feet of the tweeter. As noted, the cables have pins 1 & 3 on the XLR shorted and were made with coax to the RCA.

I checked with Sescom (Markertek). They were able to supply the diagram for their RCA to XLR cables (https://www.markertek.com/product/s...uad-3-pin-xlr-female-to-rca-male-black-6-foot). I appreciated that they were able to readily verify the cable diagram. If I'm going to buy premade, I figured why not get star quad which is no fun to solder up in a tiny space.

They took a few weeks to come in since they are custom made to your choice of length and color. I installed these and the hum is gone. They are very flexible and use Canare L-4E6S. They are overkill, but reasonably priced. Similar cables are available from other sources. I didn't open the XLR to see if the shell tab is connected.

 

[Miguelón]

What you finally get as subwoofer?

I had more or less same doubts, finally decided to go for Genelec 7050 and return the F Two. It sounded great though but prefer XLR inputs to the long term even if I had no interferences, in case in the future I go to a balanced source.

 

[nab1828]

What you finally get as subwoofer?

I had more or less same doubts, finally decided to go for Genelec 7050 and return the F Two. It sounded great though but prefer XLR inputs to the long term even if I had no interferences, in case in the future I go to a balanced source.

Still nothing. How are you liking it? I'm thinking about nabbing the F One, but the price is high and it's RCA while the 8030c pair is XLR. In the future I was thinking of adding more speakers and another sub for a 5.2 system, with the 8030c pair for surrounds, but doubling as a stereo music system separately with one sub. Is this doable in terms of wiring, for a simple dedicated music system, that becomes part of a 5.2 movie system?

 

[hitmanx]

In the USA, a great place to order components to make your own cables or to order custom-made cables is Performance Audio (https://www.performanceaudio.com/pages/custom-cables).

Their rates are very good, you get to choose the exact length, components, and wire, with a flat $10.00 upcharge for making the cable. In hindsight, I wish just went the route of ordering custom cables from them instead of making the investment in the soldering and other equipment for doing my own cables!!!

FYI, my personal recommendation for RCA (TS) <=> XLR (TRS) is the following, using 2-wire STP instead of quad-star cable. Of course, components and wire from Canare, Amphenol, Switchcraft, etc. are all fantastic as well.

• Wire: Mogami W2549
• XLR: Neutrik NC3MXX-B / NC3FXX-B
• TRS: Neutrik NP3X-B
• TS: Neutrik NP2X-B
• RCA: Rean NYS373

So, to make sure I am reading the post correctly.

Connector A (XLR 3-Pin)NC3MXX-B Black/Gold Male XLR
Connector B (RCA)NYS373-2 Male RCA Red Stripe (Black/Gold)

Custom cable from performanceaudio.

I have a JDS Labs Element IV. It has a preamp rca. Can I connect the rca cable to the preamp? For using the know to control volume.

 

[rcstevensonaz]

So, to make sure I am reading the post correctly.

Connector A (XLR 3-Pin)NC3MXX-B Black/Gold Male XLR
Connector B (RCA)NYS373-2 Male RCA Red Stripe (Black/Gold)

Custom cable from performanceaudio.

I have a JDS Labs Element IV. It has a preamp rca. Can I connect the rca cable to the preamp? For using the know to control volume.

Can you be more clear about three things for this cable you are considering?
1) What is the output (source) device -- This is Connector A:
2) What is the input (receiving) device -- This is Connector B:
3) What is the distance between devices -- This is the length from A to B

The reason I am confused is that this thread is RCA to XLR. But you have described an XLR (A) to RCA (B) connector configuration.

 

[sergeauckland]

RCA output to XLR input is easy. Just link XLR pins 1&3 and wire screen to those, with signal to pin 2.

Going the other way is more complicated as you need to know what type of XLR output you have as there are several possibilities.

S

 

[hitmanx]

Can you be more clear about three things for this cable you are considering?
1) What is the output (source) device -- This is Connector A:
2) What is the input (receiving) device -- This is Connector B:
3) What is the distance between devices -- This is the length from A to B

The reason I am confused is that this thread is RCA to XLR. But you have described an XLR (A) to RCA (B) connector configuration.

I didn’t see a rca to xlr custom cable on https://www.performanceaudio.com/pr...ble-made-from-mogami-w2549-premium-connectors

The source for xlr: Genelec 8030c
Input: jds labs element iv preamp
Length: under 4ft per speaker

 

[KSTR]

RCA output to XLR input is easy. Just link XLR pins 1&3 and wire screen to those, with signal to pin 2.

But this must be done at the source end (at the RCA connector) and then use a balanced cable to the XLR, as otherwise you don't have ground loop noise reduction.

I didn’t see a rca to xlr custom cable on https://www.performanceaudio.com/pr...ble-made-from-mogami-w2549-premium-connectors

Finally someone who got it right! The bulk of commercially available RCA to XLR male cables do it wrong, using an unbalanced cable.

 

[EngineerNate]

Redco audio will solder cables up with your choice of wire + interconnects for a very reasonable fee.

Redco Audio - Audio/Video Supplies and Accessories, Custom Cables and Panels, and more

 

[sergeauckland]

But this must be done at the source end (at the RCA connector) and then use a balanced cable to the XLR, as otherwise you don't have ground loop noise reduction.


Finally someone who got it right! The bulk of commercially available RCA to XLR male cables do it wrong, using an unbalanced cable.

Not necessarily. It depends on how the RCA output is grounded or not. I've always either used an unbalanced cable or if more convenient to use balaced cable, connected the two cores together to make an unbalanced cable. The way I prefer to do it is to use a transformer at the RCA end and a balanced cable. Bit more expensive, but reliable.

S

 

[rcstevensonaz]

I didn’t see a rca to xlr custom cable on https://www.performanceaudio.com/pr...ble-made-from-mogami-w2549-premium-connectors

The source receiver for xlr: Genelec 8030c
Input output: jds labs element iv preamp
Length: under 4ft per speaker

That link is for an XLR -> RCA cable construction, which as you note, is not what you want. I suggest contacting them directly; specifying what you want. They should be able to provide that build with the same pricing what the XLR->RCA would come out to; but I cannot guarantee it.

The important thing is that you are having a cable with 2-wire STP and not with coaxial cable; as also noted by @KSTR.

Also, you need to be correct on your terminology since that implies direction. And direction is CRITICAL for getting the proper gender on the XLR connector.

The direction of audio flow can be expressed multiple ways, such as any of the following below. But Source and Input are synonymous with each other, which is why your description was confusing.

• Connector A -> Connector B
• Source (of audio) -> Receiver (of audio)
• Output (of audio) -> Input (of audio)
• JDS labs preamp -> Genelec Speakers

 

[EngineerNate]

Fwiw redco let's you pick specific wire varieties so you can guarantee you're getting STP or starquad wire.

Probably easy enough to include a note with the order requesting a specific shield termination strategy.

 

[TehMowat]

Can I ask why you decided to go the route of gear with incompatible connections? You could avoid this entire problem by making better gear decisions. Converting unbalanced audio to XLR's isn't really great. It's doable, and you may not have any issues, but it defeats the entire purpose of balanced XLR connections. The Wiim isn't that expensive or special of a device, you could find a streamer/DAC that has balanced outputs. The Bluesound Node Icon, Cambridge CXN100 (which I have and love) are two very nice devices. If you don't want to spend that much, you could just add a Schiit DAC to your Wiim. I think the Mimir is $299 and has balanced outputs. You have Genelec speakers, and you are quibbling about how to convert unbalanced to balanced.

 

[rcstevensonaz]

Can I ask why you decided to go the route of gear with incompatible connections? You could avoid this entire problem by making better gear decisions. Converting unbalanced audio to XLR's isn't really great. It's doable, and you may not have any issues, but it defeats the entire purpose of balanced XLR connections. The Wiim isn't that expensive or special of a device, you could find a streamer/DAC that has balanced outputs. The Bluesound Node Icon, Cambridge CXN100 (which I have and love) are two very nice devices. If you don't want to spend that much, you could just add a Schiit DAC to your Wiim. I think the Mimir is $299 and has balanced outputs. You have Genelec speakers, and you are quibbling about how to convert unbalanced to balanced.

Huh??? Unbalanced to Balanced — when using a balanced (2-wire) cable — still provides substantial noise reduction potential (CMRR). The reduction is applied at the receiving end, not the sending end.

Sending from any RCA device to a Genelec speaker is perfectly fine, especially when using a properly constructed cable.

The only “problem” here is bad information, and the lack of ideally wired stock cables.

 

[KSTR]

Not necessarily. It depends on how the RCA output is grounded or not. I've always either used an unbalanced cable or if more convenient to use balaced cable, connected the two cores together to make an unbalanced cable.

You have a point here. I had implicitly assumed that a) the balanced cable is used as an extension of the balanced XLR, and b) the (-) wire and shield connected together at the RCA end... which may or may not be the case here.
Any other wiring scheme than this does not exploit the true idea of a balanced connection to reduce common-mode noise, which is to tap off the signal directly at the source and remove the GND as signal conductor so that stray currents on the GND do not affect the signal. In very rare cases it might be beneficial to disconnect the GND/Shield ("Ground Lift") at least for low frequencies.

 

[KSTR]

Converting unbalanced audio to XLR's isn't really great. It's doable, and you may not have any issues, but it defeats the entire purpose of balanced XLR connections.

This wrong, as mentioned in above post, the working principle of balanced connections is to sense the signal directly at the source side with two connections (one hot and one cold wire), it doesn't matter if that signal is symmetrical or not and to which GND it is referenced. The difference operation to extract the playload signal is then performed in the receiver but the foundation of this is where and how the input signal is sensed.

 

[rcstevensonaz]

You have a point here. I had implicitly assumed that a) the balanced cable is used as an extension of the balanced XLR, and b) the (-) wire and shield connected together at the RCA end... which may or may not be the case here.
Any other wiring scheme than this does not exploit the true idea of a balanced connection to reduce common-mode noise, which is to tap off the signal directly at the source and remove the GND as signal conductor so that stray currents on the GND do not affect the signal. In very rare cases it might be beneficial to disconnect the GND/Shield ("Ground Lift") at least for low frequencies.

But isn’t that the point of the thread: to have the RCA properly connected to 2-wire cable so that the receiving device (XLR/TRS) can apply CMRR? Or are you suggesting there are cases where using coax wire is the better option?

(And as you note on your other reply, it is an asymmetrical where the signal is only on the hot wire, with no signal on the cold wire).

 

[KSTR]

But isn’t that the point of the thread: to have the RCA properly connected to 2-wire cable so that the receiving device (XLR/TRS) can apply CMRR? Or are you suggesting there are cases where using coax wire is the better option?

Maybe a misunderstanding/language problem here.
Anyway, the preferred way of RCA out to XLR in looks like this: