Balanced XLR to RCA Adapters: Good or Bad?

I for one wonder why the SE standard is not BNC instead of RCA. BNC would seem to have the potential to sound better.

Yes, RCA's leave a lot to be desired, including the fact that during insertion the signal pin makes contact before the ground sleeve, and during extraction breaks contact after the ground sleeve. Which means that a very large transient might be put into the system if the cable is accidentally yanked out while everything is powered up. But the superior impedance control that BNC's provide is irrelevant at analog audio frequencies, and I suppose they cost a bit more. The main reason BNC's are not used for single-ended phono signals, though, is probably just that RCA's became the de facto standard many moons ago, and no one wants to step out of line. My vintage Mark Levinson ML-1 uses Camac Lemo connectors, which are far superior to RCA's, but forces the use of unconventional cables having Lemo's on one end and RCA's on the other end, or else (gasp) Lemo to RCA adapters, which is what I use.

Best regards,
-- Al

"As for using the adapters, Doug is right on. You will hear the degradation even if you use Rat Shack lamp cord."

Agree, but the question IMO is not only whether there will be some loss of fidelity now, but how the OP can best get to his next levels of performance. The OP is adding an analog source that retails for >$5000 and has not yet decided what amplification upgrades to consider, if any.
As good as the NAD is for $200 gear, I would bet good money that he will very soon be in the market for a comparable phono pre-amp, etc. Since he hasn't ruled out balanced amplification as an option, why perform a modification that you may want reversed in the near future?
Having owned the NAD amplifiers, and also having used XLR-RCA adapters with Ayre and Jeff Rowland amps from time to time (JRDG actually supplies them), I can assert that the adapters may not be the weakest link and are worth a try, even if you just borrow a pair.

Franz456, my one experience with adapters is negative. In my case I just purchased a Triplanar VII arm terminated with RCAs and I had an Ayre P-5X which is a true balanced phono preamp (Cart was/is a ZYX Universe X .24mv). I had been using an XLR terminated phono cable with the JWM 10.5 (VPI Aries 2) before the Tri. I got the "Cardas" adapters the same time I got the Tri and in my case I needed an RCA female to XLR unit.

With the Tri and adapters in place I was disappointed. The P-5X has XLR and RCA inputs so I switched between adapters and the reg RCAs and after putting them in the adapters a second time it was clear to me the they were bad. Just as Doug and Atmosphere said, it zapped life from the sound. Yes I am being a bit dramatic but it was more than I would have thought and it was easy to tell the difference.

I do agree with the above post, if you want to go that way, try some cheap ones first.

TD

TD, I don't know about the Cardas adapters, but the RCA-female to XLR-male adapters that I have seen connect the ground sleeve of the RCA connector to XLR pin 3, and to XLR pin 1, and to the XLR shell. If the adapter you were using was similar, it would mean that one end of the cartridge coils would have been connected through the adapter to both the circuit ground and the chassis ground of the Ayre phono stage. That would certainly figure to have adverse sonic consequences, in part because it would amount to putting an unbalanced signal into the Ayre's balanced signal path. But as I see it those consequences have no relevance to adapting an XLR output to an RCA input, as the OP is considering doing.

Perhaps some of the negative experiences with adapters that were cited by the others had similar causes?

Regards,
-- Al

Al, good point. I have an ohm meeter and I should be able to test that in the next day or two.

Thinking about it an adapter should have a tiny effect.

Just before the Triplanar here is what I had. A VPI Aries 2 with JWM 10.5 with the standard RCA output block. Having the Ayre balanced P-5X phono pre I special ordered an Audioquest Cheeta half meter (I could go that short) cable that had RCA plug goiing to the VPI rig with XLR for the phono pre. That cable is a balanced cable and keept the +/- phase signals floating even in that confiiguration. This is nothing more than a long atapter! It worked great. So I have a hard time expaining what I experienced with the Triplanar continous cable from cart clips to RCA plugs and the RCA/XLR adapters. But taking them out made clear difference.

TD