Balanced to RCA

@david_ten

Thanks for the mention, David. Most (but not all) XLR-to-RCA adapters ground the signal on XLR pin 3, i.e., they connect pin 3 to pin 1, which is the ground pin. In the case of most (but not all) components providing XLR outputs that kind of adapter should not be used, for the reason @mike_in_nc stated. And the same considerations apply in the case of an XLR-to-RCA cable.

Following is an excerpt from what I had said when we discussed this issue via PM in November 2018:

An adapter that shorts pin 3 to pin 1 would be appropriate when adapting an RCA output to an XLR input, and would be appropriate and sometimes even necessary with **some** designs (especially some tube-based designs having transformer coupled outputs) when adapting an XLR output to an RCA input. However in many cases, especially cases involving solid state designs having low output impedances, such a short could cause adverse sonic effects, buzzing, or even damage, eventually if not sooner. I once diagnosed a severe buzzing problem that occurred with a member’s CD player which was caused in exactly that manner. When he went to an adapter cable which left pin 3 open everything worked fine.

You subsequently received a response from the designer of your Grandinote preamp stating that pin 3 should be left open (unconnected) when adapting its output to an RCA input.

And chances are that would also apply to the OP’s situation, but not necessarily. For a firm conclusion to be reached he should either ask the manufacturer of the component providing the balanced output (as I see Mike suggested just above), or let us know the specific make and model of the component and we may be able to determine the answer.

Best regards,
-- Al

I am going through the same labyrinth
I have a before-amplifier ( not to be confused with the preamplifier) (It is a dox drive rack) which I’ll be using as an external crossover. It has female XLR inputs and male XLR outputs. My question is what is the best way to convert
RCA to XLR (cd player to dox)
and
XLR to RCA. (dox to amplifier)
  

-typically on the second half Im wondering which would be preferred ?
1. xlr cable from the dox to either: 
     A. Cardas Audio Male RCA to Female XLR Adapters plugged onto my amplifier (McIntoish 2105)
     B. A transformer. (SO max}

What I like about A. Is there is only one set of cables versus B. Two sets of cables.

depending on my speaker choice Ill need need to be bi-amping or tri-amping… so cost is a consideration x2 or x3…

2.???


My brain isn’t intended to be used in complex matters such as this...

Im just trying to go from:

 CD player to dbx
(balanced to balanced?) 

then

dbx to amplifier (balanced to unbalanced?)

• (Pin 2 is connected to the center RCA pin and Pins 1-3 are grounded to the RCA chassis body)

• (Pin2 is connected to the center RCA pin, Pin1 is grounded to the RCA chassis, while Pin3 is connected with a 10 ohm resistor to the RCA chassis)
  
  

• (Pin 2 is connected to the center RCA pin and Pins 1-3 are grounded to the RCA chassis body)

• (Pin-2 is connected to the center RCA pin, Pin-1 is grounded to the RCA chassis, while Pin-3 is connected with a 10 ohm resistor to the RCA chassis)

Ghentaudio manufactures nearly every possible configuration of cable you can imagine. Decent quality and great service. I have 2 pairs of RCA to female XLR , one going from DAT player/recorder and the other from a CD burner to a Schitt Freya preamp in a little system I have in my home office and 1 pair of XLR male to RCA in the main system going from CD to pre. No grounding issues. No adapters.

https://www.ghentaudio.com/

even if it is stated that pin 3 should be left open, that’s an invitation to residual captive flutter on the open pin, which will make the highs simultaneously darker and more extended.

The flutter of residual capacitance on the open pin will modulate the return line, as it will be read as signal and thus dealt with by the balanced function itself. And thus micro mangle the transient data of the positive pin’s throughput proper... Basically mis-timed and mis-shaped transient information.

Which will be heard, even if it is very very small, as the ear works solely on interpreting transients and their placement in time and grouped as harmonics in each micro level placement in time.

That’s how we hear. We only process about 10% of the audio signal and all we process is the transients and micro transients, in level and timing placement.

So the tiny flutter of an open pin three, is going to produce a signal that is heard. People have various learned and inherent hearing skills so some might not hear it but I think most will.

Maybe not ground it but tie it down through high resistance of some sort. Cut out any possible micro-capacitive flutter, if one can.

Basically, it depends upon how pin 3's open condition is dealt with by the manufacturer. How sensitive it is to potential modulation. That we see many circuits, even if they are resistively loaded (even when unplugged) , they can have caps or plugs put on them, to block stray signals and such from occurring, or interfering with the open condition.