XLR to RCA cable problems.
Jul 9, 2008 at 10:51 AM Thread Starter Post #1 of 14

ninjapixie

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Hi everyone, I've started using the balanced outputs of my Cambridge 840c using an xlr to rca cable because my cheap studio monitors only have rca inputs. The rca outs of the 840c go into my headphone amp.

The problem is I start getting intermittent popping sounds when using the xlr to rca cable to my speakers. Connecting them to my headphone amp instead produces the same popping sounds through my cans. I suspect it's a power issue.

Is it just wrong to use an xlr to rca cable, or is there something else that's happening?

Could it be the balanced outputs of my player are faulty?

Can anyone help?
 
Jul 9, 2008 at 11:20 AM Post #2 of 14
Not wrong, but wiring configurations can differ depending on the products you are using. For a benchmark DAC for example, you have to leave pin 3 of the XLR connection floating when terminating with RCA at the other end.

Not sure of the answer specific to your gear, but perhaps you need a similarly configured cable?
 
Jul 9, 2008 at 11:59 AM Post #4 of 14
Thanks for the replies.

I had no idea about the cable configurations, nor do I have any idea how to find out which pin of the xlr is floating. Do I just unscrew the rca or the xlr and see what's connected or not? Would I damage the cable doing this?

I must add, the back of the Cambridge 840c where the xlr connections go gets very hot, almost untouchable. The rca outputs don't get anywhere near as hot and work perfectly fine.

I read somewhere that the 840c doesn't have true balanced outputs. Could this be the problem.
 
Jul 9, 2008 at 12:37 PM Post #5 of 14
I use the two sets of balanced XLR outputs from my DAC to feed two seperate headphone amps using XLR -> RCA cables. They are Chord Chameleon Silver Plus cables.

I have been doing this for sometime with no problems at all. In theory what you are doing should be possible.
 
Jul 9, 2008 at 12:38 PM Post #6 of 14
Open up the XLR plug, take note which wires (including shield) are connected to which pin (1,2 or 3). Do the same with the RCA end, this time noting which is connected to the center pin and to the sleeve/barrel.

Edit: Alternatively, continuity test using a multi-meter will achieve the same result without opening the plugs.

Cheers!
 
Jul 9, 2008 at 12:53 PM Post #7 of 14
I've opened up the xlr end and couldn't tell if any pin was disconnected. I think they were all connected. I couldn't open up the rca end. I may be able to if I used brute force but I'm afraid I'll break the cable if I do that.

Considering no one else seems to have this problem, I fear it may be the Cambridge 840c that's the problem as it supposedly doesn't have true balanced outputs. I'm going to get a xlr-xlr connection tomorrow and plug it into something balanced (I'm sure my dad's receiver as balanced inputs) and see if the problem still persists. If the problems gone, it's definately the cable that's the problem.
 
Jul 9, 2008 at 3:03 PM Post #8 of 14
Quote:

Originally Posted by Zorander /img/forum/go_quote.gif
Alternatively, continuity test using a multi-meter will achieve the same result without opening the plugs.


The cheapest basic digital multimeter ($10 or so) is good enough for this task.
Measure which RCA pin is connected to which XLR pin. Also measure if there are shorts between any two XLR pins.
I suspect that you'll find a short between XLR pins 1 and 3. This is a common bad practice because typical circuits are not designed to work into a shorted output.
mad.gif
 
Jul 10, 2008 at 6:09 AM Post #9 of 14
Thanks for the help everyone.

I went to a music store to get some balanced xlr-xlr cables and got myself a passive volume attenuator to plug them into. Using true balanced cables into the attenuator there was no popping sounds so the problem isn't the 840c (phew). Obviously the cable is the problem.

Using rca to trs adaptors to go into the balanced outputs of the volume attenuator (Nano patch), I'm now able to go pseudo-balanced without the need for the xlr to rca cable.

I must say things are certainly sounding better using the balanced outputs. The stereo image is wider and with it comes slightly more detail. There is definitely an improvement in sound which can't be attributed to the cables (I'm using Hosa cables ), so I'm very happy.
 
Mar 30, 2009 at 1:50 AM Post #10 of 14
I bought some RCA to balanced cables (Time-Portal cables), connected them to my CD player (RCA inputs) and then to my RP-1000 headphone amplifier (the balanced inputs on the back). I turn both the amplifier's and the CD player's volume up full bolt but I can only just barely hear a noise. I then reconnected my Van Den Hul L & R cables and everything's working again. Oh well I emailed the place where I got the RCA to balanced cables from because maybe there's something wrong with them.
 
Apr 2, 2009 at 3:36 AM Post #11 of 14
I use an Isomax XLR-RCA transformer to connect balanced to RCA. I plug my XLR cable from DAC into the box and plug my RCA from amp into the box, and everything works just great with no worries about what pins are connected to what.
 
Apr 2, 2009 at 5:28 AM Post #12 of 14
It's not a "problem", using half of the balanced signal can make the DAC unstable (as + to Ground sees a load and - to ground does not). That's the design of the DAC. If your "adapter" (I call it hack-job) also grounds the inverting output (connects - signal to ground), you may destroy the DAC. Basically, don't do this, just use a pair of RCA splitters.
 
May 26, 2012 at 6:49 PM Post #13 of 14
I have the same problem, I'm also getting intermittent popping sound etc.
 
I've connected the balanced output  (1/4" TRS) of my emu 0404 to my amp using a RCA cable with RCA to phono adapters.
I get occasional pops and clicks etc in this configuration. When using the other output  (3.5mm stereo to RCA) I have no issues. It must be a limitation of the DAC or  
the cable needs to be wired differently. 
 
May 27, 2012 at 11:04 AM Post #14 of 14
Some ballanced componensts have much highter outputs on the ballanced out compared to the RCA outs on the same device.  If you have a 'strong' ballanced out and connecting it to a 'sensitive' RCA in you could be overdriving the amp.
 

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