Why so few devices with BNC's??

in my system i mostly use BNC’s for my interconnects.

but it’s not that simple.

i use the darTZeel ’zeel’ BNC 50 ohm interface between my preamp and amps, and between my tape repro and my preamp. then i use RCA’s between my phono pre and preamp, and XLR’s between my dac and preamp. 2 of my sources do not have the proper interface designed into them so i can’t use the ’zeel’ 50 ohm with them.

the ’zeel’ BNC 50 ohm interface is superior to either RCA or XLR. part of it is the robustness of the BNC connection itself with it’s positive secure mechanical lock, but mostly it’s precise impedance matching between components which greatly reduce signal corruption. RCA and XLR will cause echo’s in the signal.

Herve Deletraz of darTZeel uses the ’zeel’ interface for all darTZeel products. there are a few other products out there, such as CH Precision (one of the owners of CH are actually family with Herve) that also include the 50 ohm BNC connections in their products.

properly executed, the 50 ohm BNC interface will sound the same up to .5 kilometer.

IMO there's no sense in even talking about digital coax using RCA's.  It's simply a flawed implementation.  People can argue about whether it's significant or not, but it's flawed regardless.  With proper BNC's it's no longer an issue.  Then the subjectivists can simply debate the merits of 70 ohm cables. 

I've taken the approach of simply not using gear with RCA's in my "serious" setup.  If the manufacturer can't be bothered to go to the trouble of having a BNC connector then I can't be bothered to buy their stuff (same goes for AES/SBU ro the absence thereof).  There have been a couple exceptions though, where I've gone to the trouble of retrofitting BNC sockets.  I did that on my Cambridge CD transport and some other gear in the past. 

Interestingly there IS a fair amount of gear with BNC's, and it seems to generally be such "boutique" suppliers as Lumin, higher end Schiit stuff, Bryston and numerous others.  Mark Levinson or the Japanese?  Not so much. 

I think the RCA and BNC thing was a bigger deal 10-20 years ago. My understanding and I have not done the math is the slow edges of SPDIF make impedance matching not as critical. With the interfaces and DACs today most of them should shrug off a lot of jitter. Our speakers are pretty immune unless things get really bad.

Does Dartzeel use 50 ohm for analog too? I just read something about that on 6moons and seems they do. It was supposed to be a technical dissertation. I think someone nose grew a few feet when they wrote it. It started with a flawed premise than used flawed examples to make a case. Not good. Not good at all. We don’t normally send audio 0.5km but 0.1km is not unusual with balanced differential AES. With any single ended, the ground loop from the distance will be too noisy.

@thespeakerdude

darTZeel only makes analog products except for one integrated amp with a dac in it. the ’zeel’ 50 ohm interface is strictly analog only.

Herve Deletraz of darTZeel wrote an article published in the Sept 2001 issue of Stereophile about Impedance Matching in audio. it’s quite technical. but if you doubt the logic of the 50 ohm BNC advantage for analog interconnects, then you should have the tech knowledge to follow it. it’s serious.

https://www.townshendaudio.com/PDF/Impedance_matching%20deletraz%20paper.pdf

he wrote that article before he launched his audio company where he applied the principles mentioned and included the ’zeel’ BNC 50 ohm interface in all his products.

i have owned darTZeel amps and preamps since 2005 and always used ’zeel’ 50 ohm interconnects. compared them many times to conventional interconnects and always preferred the ’zeel’.

you have a right to your opinions, but there is real science behind the 'zeel'.

@mikelavigne ,

I am not an EE, but I work around them every day, and I have a physics background so I get the concepts. Turns out the 6moons article was excerpts of the one you linked. I don't feel a need to change my past statement, a flawed premise followed by flawed examples. Been around professional audio speakers technically a long time. This "idea" of impedance matching for analog in audio has been around since the 1990s from Goertz. He even patented it: https://patents.google.com/patent/US5393933 for speaker cables.  It keeps rearing it's head every once in a while, gets shot down because it does not work, and then it goes away till it comes back again. With speaker cables, these low impedance cables created problems without solving any, they caused some amps to blow up. It's bad science or marketing.

Maybe one of the EE's out there has a better graph or can make one. I tried to Google a good graph, but didn't have much luck finding one. Not sure this is a 50 ohm or 75 ohm cable, but does not matter, the principle is the same. That number does not work for the frequencies we hear.