More on XLR vs RCA considerations?


Have read much about the differences between balanced vs unbalanced circuitry and the interconnects that go with it. The consensus seems to be "mostly" in favor of balanced when it is available. There are at least a few who seem to prefer unbalanced. Perhaps if the circuitry (caps etc.) becomes equal between the two, there is not much advantage to XLR? Not sure, myself. I like to have the option even though I've never used it, just makes me feel good, knowing it's there if I ever decide to use it. Long wire runs seems to be the main reason. Are there others? I heard, lowers noise floor with higher gain. OK.

I've never seen a Conrad Johnson amp or preamp with XLR connections. Maybe they exist, don't know but I've never seen it. CJ is certainly respected in the high end audio world. I'm just curious as to why they would never build with balanced circuitry. Any thoughts on why not? I'm just curious.

Bill

billpete

Yes that is my experience - the cable transport itself does not matter too much, XLR versus RCA, for a home environment where runs are typically "short" (say 5 meters or less) and cables are shielded enough for the environment and signals carried.

HOWEVER, the circuitry engaged on either side of XLR & RCA I/O can vary a lot, and when the XLR path uses a symetrically "doubled" cricuit, and the RCA path uses only half of this, then it usually sounds better (sometimes significantly so) to go XLR, and often results in +6dB extra gain too.

Some circuits will take RCA input and invert / mirror it with an extra circuit (or opamp) to make a balanced signal, at slight perfromance penalty (versus the XLR input) - then run it through the balanced (doubled) circuitry all the same. Some will use an I/O transformer to do this on one of the other side (or both), adding the coloration of the transformer itself (which you may or may not like).

Then there are true differential inputs which are the only ones that don’t care what you feed into them. I have some high end headphone amps like this. You can feed in RCA or XLR with no difference in perfromance between them, and no penalty from extra inverter stages applied to unbalacned input sources. You can even send an unbalanced signal through its XLR inputs (e.g., via RCA -> XLR adapaters) and it’s fine too. Really cool; this is my favorite, though it is still not too common. Sometimes the amps like this are called Super Symmetry or SuSy, though that name is from Pass Labs. Pass Labs also has a different twist on its lower-level phono stages (Xono, XP-17), whereby the XLR *output* stage uses an extra inverter stage with +6dB gain. I haven’t directly compared them yet to determine if there’s a penalty to the XLR outs for this, but I can say both its RCA and XLR outputs sound excellent.

If you’re just "guessing" with unknown cricuitry, then usually the XLR path will sound better. But it’s not a guarantee.

On the cables themselves: I despise wrestling short, stiff XLR cables into place (pin alignment) - whereas an RCA conenctor can easily rotate-slide onto its jack from any angle! Audioquest’s later lines of XLR cables added a hard slippery nylon fiber net on their outer covers (for looks), which causes the strain relief to fail after several cycles of this "wrestling". This annoys me to no end. Their older models with soft cloth coverings are much much better here.

Thanks for the replies

None of my wire runs exceed 4 feet and most are 2 feet or less. Some could be done with a foot, just don't have any IC's that are that short. I may have some made. I've been using some DIY stuff made from "Beldon wire and Neutrik connections. Seems fine to me.

Talking about everything being balanced. What can be balanced besides my preamp and amplifiers? I don't think I've ever had or seen any XLR's anywhere else. Is this what is meant by "all balanced", just the preamp and amps?

Thanks

Is this what is meant by "all balanced", just the preamp and amps?

Plus sources (output side) - that’s pretty much the bulk of it. This can be extended to phono stages, tape pre-preamps, headphone amplifiers, tonearm cables, and step-up transformers. What else is there :)

"Doubling up" the circuitry inside pretty much always doubles the expense. 

Nothing that I have, has XLR connections except for the preamp that I just bought and my amps. I run my speakers bi-amped. The Calypso pre has XLR connections and RCA's at every input and output and includes 2 outs for my amps. It seems the perfect set up for me. I have seen some ARC's that have this same arrangement, which seems nice to me. I just don't have anything else that has XLR's. My VPI TT has a nice MIT 330 cable, DIN to RCA. My SUT, which I don't always use, has RCA's only as does my Cary Phono preamp as does my Denon CD player. I don't stream and I don't have any other devices. Would using XLR from preamp to amps be defeated by the fact that I have nothing else that is XLR or would connecting my amps by XLR make for an improvement anyway?