XLR passive split vs switchbox?

I've seen this topic a variety of times throughout the studio forums, but never in hifi forums. I understand that some gain is lost with a passive split, but is there any SQ loss with make-up gain in a mid-fi system (around $10k after the split)? If the answer is "no", is there any meaningful impact to SQ when downstream components are upgraded to the  $20-30k level?

In my application, the analogue component before the split has an output impedance of 75ohms at 1kHz. I contemplate splitting the analogue signal between: (a) an ADC converter (5.5kR or 5,500 ohms vs 14.5 kR or 14,500 ohms depending on the input), and (b) a Radial Twin ISO box (600 ohms in and out) which will feed an Schiit Mjolnir 3 preamp downstream.

If a split is a bad idea I could also simply use a switcher box, but I'd like to simplify the setup where there is no meaningful impact to SQ. What's the consensus within the hifi community on passive splits?

Looks like Paul from PS Audio has weighed in on this topic at least twice, and opined that a passive split with a Y-cable won't make any difference if done right:

I suspect that splitting a balanced signal would be even less susceptible to degradation. If anything, perhapse my Radial Twin ISO box may cause an issue due to only being 600 ohms - I'll have to experiment with taking this component in/out of the chain.

If there are any other perspectives, please speak up! Otherwise I'm happy to let this topic rest with Paul's opinion.

On XLR balanced interconnect, there are two different forms:

• low output impedance to high input impedance link (I don't know English term for this, it is literal translation from Japanese term): this is explained by Paul.
• “impedance matched” 600Ω output to 600Ω input signal transfer: This method is used to maximize the signal power transferred, it is used between active device and passive device, such as the preamp to your galvanic isolation transformer.

If you'd like to Y split and isolate the XLR signal of preamp, it is better to Y split after isolate, than Y split then isolate each branches.

All modern XLR balanced interconnect systems are:

low output impedance to high input impedance

600 Ohm systems are from the 1960's or earlier.

There should be no signal level lose with most splitters.

On 9/12/2024 at 5:00 AM, Speedskater said:

All modern XLR balanced interconnect systems are:

low output impedance to high input impedance

 

600 Ohm systems are from the 1960's or earlier.

I think Luxman Balanced XLR output is 600Ω.

Still, their balanced input is high-impedance, so, you are correct, it is low output impedance to high input impedance link when 600Ω transformer is not used.

This is from their latest CD player D-03x specifications.