XLR/RCA

[Coytee]

Taking an unbalanced (RCA) output and feeding a balanced input (XLR)?

This is what I'm doing

[mark1101]

Doc,

What you are talking about is something different. Roy did have the mod you speak of but also provided help for those connecting a home audio preamp to the Pro dx-38.

Reference the manuals I quote above. They are components I own and so I know those manuals. There are MANY others that say the same exact thing.

When you connect a home audio device (RCA) to a Pro audio device (XLR) you need to make sure Pin 1 and Pin 3 are NOT tied together.

Benchmark goes so far to say that if they are tied together you will overheat their device and damage it.

The "unwired" XLR to RCA adaptors (with pin 1&3 separated) are widely available and that is what I purchased for my system rather than just opening a standard "wired" XLR to RCA adaptor (with Pin 1&3 tied together) and cutting the wire.

[babadono]

Pic 1

Coytee,

If that's what you are doing you should wire it this way. This allows the chassis current to flow from the pro equipment (XLR pin 1) on a seperate wire (the shield) to the chassis of the consumer equipment (RCA shield). The signal low side (XLR pin 3) which in this case will just be signal return will not carry any inter chassis current. If this causes a ground loop (audible hum and/or buzz) you have other problems that need to be addressed.

babadono

[babadono]

Coytee,

Well that did not work. I am trying to point you to XLR-RCA1.gif from a previous post in this thread. You should wire it like this. NOT XLR-RCA2.gif.

babadono

[mark1101]

If you connected a Benchmark DAC to a home audio preamp for instance via the method you just mentioned (leaving pin 1 & 3 tied together), you could cause a perfectly good $1200 Benchmark DAC to fail. The manual clearly instructs you to separate Pin 1 and 3...........in other words only run +/- to the RCA and no shield.

My Ashly Protea 4.8SP processor manual instructs the same: separate Pins 1&3.

We have had other forum members with noise and shorting issues remove the connection between Pin1 &3.........and all went well.

Do an internet search on adaptting balanced to unbalanced or XLR to RCA............and you get separate Pins 1 & 3.

Seriously, am I missing a situation where you want Pins 1&3 connected together in scenarios we are discussing?

[babadono]

Mark1101,

My apologies to any and all that I have offended.

Sorry, I am not trying to dictate only make suggestions to the best of my ability and understanding. That being said in a home environment if tieing 2 chassis together causes a problem be it hum, buzz or fire there is a problem. And it is not the XLR/phono cable.

I mean in a home you just have to figure out and fix the problem once. Its not like you are packing it up and moving it down the road to another show tomorrow night.

babadono

[mark1101]

No offense taken at all. I thought I could be wrong and don't want to spread bad information. The point is that we get Coytee straightened out. I just think it may be the Peach itself in his case which is a known component design issue. Great preamp............ but its designer noted that he had no intentions to make it compatible with pro signals and a few of us (I have a Peach too) have found this out from trial and error. The Art Cleanbox improves the connection but still leaves a degraded sound.

In my own applications where there are no gross imcompatabilities and from what I posted above.........providing signal from an RCA to an XLR using + from RCA to Pin 2 on XLR and shield (ground) on RCA to Pin 3 on XLR.....with Pin 1 (XLR Shield) disconnected from Pin 3................this works.

If there are other balanced to unbalanced applications where another wiring scheme is better or required, I apologize because I'm not aware. Just trying to help.

[DrWho]

Going from an unbalanced output to a balanced input is a different wiring scheme than going from a balanced output to an unbalanced input.

[Coytee]

Currently at home in TN, borrowing my sis-in-law's laptop.

Regarding RCA -->XLR, I unsoldered the pin (forget the number) and left the wire hanging. I then plugged everything toegether without the headshell of the XLR attached so I'd have access to said wire.

I touched it to the pin and removed it. In all cases, it sounded better with the pin attached (not shorting the two pins together) so I soldered it to the pin and closed it up.

I've removed the Cleanbox and you can't hear a stitch of hum at the seating position although if you put your ear about 12" outside the bass bin you CAN sense some. A very small amount.

I already have some XLR/RCA adapters. I've always presumed they were throughput, meaning, didn't have anything sorted inside them. I will pull out my VOM just to educate myself.

Been looking around the house for a box that I should have moved with me. Couple remotes in the box as well as the digital camera. So far, not finding it at all. Still a bit dumbfounded as to what could ahve happened to it.

[mark1101]

When you disconnected one of the pins temporarily you say you don't know which (1 or 3). Well, that's not good Richard!! You may have disconnected the actual audio wire and may have been running on the shield instead. The test should have been to run on the 2 audio wires in the XLR cable with the shield disconnected.

This is pretty elementary right? An RCA has 2 wires (center conductor and shield/ground) and an XLR has 3 (2 wires and a shield around them that is connected to one of the pins). What all my posts have been saying is that you want to use 2 wires all the way through, not 3. Inside an XLR cable is 2 wires and a shield. We want to use the 2 wires and get the shield out of the picture temporarily to determine if that makes an improvement. That was the test.

But what I had been saying all along.............and I'm not sure what you have now...........is that if your preamp is a Peach........all bets are off. That is never going to work right with a pro amp as stated by Mark D. long ago. Whatever noise you have can be minimized to an extent with a cleanbox but there will still be signal loss and degraded sound. I did the same deal and went through all of that until I finally consulted Mark D. He explained it all to me and I just got a different preamp after that and the issue went away. I ended up with a McIntosh C220 which is nice because it has balanced and unbalanced inputs and outputs. I wasn't about to go through all that crap a second time. Now I can interface to home audio and pro audio stuff without these type of issues.

Where I still need the so called "unwired" XLR to RCA adaptors is for the outputs from my processor which are balanced XLRs. The inputs to my McIntosh amps are RCA. So for me the "unwired" adaptors were required for XLR output to RCA input. When I used standard "wired" adaptors the signal was shorted out and I got a low level and noisy output.

EDIT: I see now that Doc makes an important point. I am talking about XLR output and RCA input...........I think you are talking about RCA output and XLR input.

[Coytee]

EDIT: I see now that Doc makes an important point. I am talking about XLR output and RCA input...........I think you are talking about RCA output and XLR input

Heh...yep RCA out (Peach or Lexicon) and XLR in (Dx38)

Truth be told, I didn't realize there might be more than one way to wire a simple RCA/RCA wire.

I would have thought that a simple RCA/RCA would have had two, perhaps three wires. Hot wire to the pin (attached to the pins on both ends). another wire for ground, attached to the ground on both ends. perhaps some 'fancy' wires having an external sheath that would also be attached to EACH ground or, as i've since learned, floating at one end.

i think that last situation (2 wires & ground) is now a misunderstanding on my part and the external sheath I see on one of my Discwasher brand 'gold ends' connector is actually in lieu of the ground wire.

So it looks like this Discwasher RCA has an internal wire that is attached to the hot pin on either end of the wire. It then looks like the entire wire is covered with this sheath and this sheath is what is the actual ground, connecting both RCA grounds.

now, we get into the logic of floating one end of the ground so that any noise drains away to one side....

sigh

Maybe I'll just buy some Bose and be done with it!!

[]

Actually, what I've been doodling around in my head is buying the Lexicon 12??? unit that has XLR outputs. my only issue with it is it only has a single HDMI output and if I use it in the house in TN, I can see a benefit to having two HDMI outputs.