Why, Decades Later, Do We Still Use RCA Plugs & Jacks?

Grainger49 · 6876

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Offline Grainger49

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on: February 24, 2011, 10:20:22 AM
I know that RCA plugs/jacks were used in the 50s, probably earlier.  It is a pressure fitting.  There are so many better connectors today.

Why doesn't audio use them?  We, as DIYers, could use BNC connectors, F Connectors or a number of other, more robust, connectors.

Why?



Offline Maxwell_E

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Reply #1 on: February 24, 2011, 10:47:05 AM
I've looked at some nice silver BNC connectors we carry in my lab. I never got around to it because I was concerned with compatibility issues with other pieces of gear.

Max Tomlinson
SEX amp, Tode guitar amp


Offline JC

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Reply #2 on: February 24, 2011, 10:58:41 AM
Which, I'd say, probably goes right to the heart of the matter, Maxwell E.

Other than the computer industry, which likes to use new connectors every few seasons to create compatibility issues with older gear to ensure new sales, most of the rest of the electronics field tends to see compatibility as a positive feature.

So, unless a new connector can be shown to be radically superior in function and/or price, enough so to risk incompatibility with traditional standards, it probably is not going to happen.

Jim C.


Offline corndog71

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Reply #3 on: February 24, 2011, 10:59:31 AM
I've often wondered that myself.  

It's a shame speakon connectors aren't more prevalent as they make a nice, short-free connection for both polarities all at once.  Of course the masses are still using 18awg zip cord with spring connections which are barely effective.  I'm surprised a simpler yet still secure method has not been established.

BNCs are great and really should replace RCAs as well as F connectors.

F connectors are a pain and should be eliminated.

The world was made for those not cursed with self-awareness.

Rob


Offline rif

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Reply #4 on: February 24, 2011, 11:22:25 AM
What timing -- I just ordered some BNC connectors for my next project!  I'm also making my own cables, and plan on making at least one set with BNC on one end/RCA on the other.  No compatibility issues here I hope.  So I'll have 75 ohm cable and 75 ohm connectors. I like symmetry.

One pitfall with BNC male conn. seems most requires some kind of crimping tool (no soldering), which can be expensive. On the other hand, BNC connectors seem to be tailored to specific cable -- male connectors are made for Belden 1694a, 1855a, 1505a, etc... Very nice IMHO.




-david


Offline Maxwell_E

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Reply #5 on: February 24, 2011, 12:18:31 PM
The lack of a solder option for connectors could be contributed to a lack of demand by the audiophile/DIY community. We seem to be pretty happy with RCA, and there's lots of options out there. And like rif said, BNC connectors are used exclusively with shielded coax cable, with crimp connectors for the shield. And most BNC's are made to work with the specific types and diameters of coax cable due to the crimp connection, limiting choices on custom cabling. I'm not sure if any company produces a solder terminal, DIY-oriented BNC plug.

Max Tomlinson
SEX amp, Tode guitar amp


Offline HF9

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Reply #6 on: February 24, 2011, 02:32:11 PM
Vampire makes a nice BNC female, I've upgraded a couple pieces of equipment with it. It's meant to be soldered to a PCB but you can panel mount it and solder wire to it without issue. Furutech Rhodium plate BNC males are quite nice if you are building a cable. You strip a 75ohm coax cable, pull the shield back, and the BNC connects to the shield securely without solder, and you solder the center conductor.

My DIY Audio Electronics Blog: DIYAudioBlog.com


Offline Paul Joppa

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Reply #7 on: February 24, 2011, 02:58:21 PM
BNC connectors are standard in acoustics laboratory settings - in fact, most electronics labs use them exclusively. And BNC to RCA adapters are readily available; even RatShak has some gold-plated ones for less than $10. So it's easy enough to build with BNC jacks and still use RCA cables.

Of course the audio standard is still the XLR with balanced lines!

Historically I think the RCA plug was invented for long-wire antennas connected to Am radio sets; its purpose in life was to be even cheaper than whatever they were using before.

Paul Joppa


Offline Grainger49

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Reply #8 on: February 24, 2011, 11:47:16 PM
PJ your last sentence says it all.  

I was aware of the female RCA to male BNC adapter at the Shack.  I had to buy one for my Ack! dAck! since it has a BNC input.  It is the only DAC I know of that has one.  Of course Ack! sells a cable that is RCA on one end and BNC on the other for a premium price.
« Last Edit: February 24, 2011, 11:50:01 PM by Grainger49 »



Offline howardnair

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Reply #9 on: February 25, 2011, 05:07:24 AM
this question prompted some googling--the only  answer after about an hour of searching  was simply  "they work" not a very exciting answer-possibly in the future cd players and amps will come with conventional rca/xlr  connectors and a usb type connection and maybe eventually just a usb type connection-and some smart diyer will make a little interface  pcb plate that we can all remove our rca's , rewire and use a usb type --possibly and maybe--but what will i do with all my scott, bottlehead,turntables, etc ???  use the rca's because "they work"!!!!!



Offline coca

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Reply #10 on: February 25, 2011, 05:48:14 AM
The use of RCA connectors has been a topic for discussion for a long time. However, I've made interconnects used for single ended connection with BNC's, XLR's, and of course RCA's, and I often connect the input of a preamp directly to the volume control if I am only having one input.I don't know if there is any advantage soniclly by using the different connectors, but I found that there has been a definite inprovement in sound quality when connecting the input direct.



Offline Grainger49

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Reply #11 on: February 25, 2011, 10:15:51 AM
Pat of what caused the post was reflecting on the Incognito/Cardas/Rega tonearm wire upgrade kit.  It is four Litz wires from the soldered cartridge clips to the RCA plug that goes into the phono stage.  In other words each of the four wires has only 2 soldered connections from the cartridge to the Phono stage.  Then that crappy connection to the phono stage.

Often arms/turntables will have other connections between the cartridge clips and the input of the phono stage.  Those are most often fittings that rely on the pressure of the pins and jacks to make the connection for the smallest level of voltage in our systems.  The pressure connection is flawed at best.

Yes, the Incognito/Cardas/Rega tonearm wire upgrade kit has one pressure connector at each end.  But that is the minimum number of bad connections you can have unless you solder the phono leads to the phono stage.
« Last Edit: March 03, 2011, 08:58:34 AM by Grainger49 »



Offline Grainger49

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Reply #12 on: March 03, 2011, 09:10:35 AM
In that I built my Phono stage and can change the connectors at the end feeding it I can get some BNC connectorsplugs.  Matter of fact, I have several chassis mount BNC connectors already.



Offline Grainger49

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Reply #13 on: September 19, 2013, 03:16:15 AM
And now a reasonable replacement:

BNC Connector ~$1.50

The crimp tool costs $33, but we could make a group buy and send the tool to each other.
« Last Edit: September 19, 2013, 06:32:22 AM by Grainger49 »



4krow

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Reply #14 on: September 19, 2013, 06:09:48 AM
  Maxwell,
  In regards to your question about a BNC connector using a solder connection-when I was working for the phone company, we actually had that option. It was the smallest hole in a pin you ever saw! More than just curious, I tried it, expecting to fail. The solder lept into the hole the first time. Hmmm, somebody thought this out.

  G,
  Just try to solder your phono cable to the cartridge itself, I TRIPLE dog dare you ;D   :-[

 I am not a great fan of the RCA because there seems to be slight differences between companies when it comes to fit. Hell, some of them come off with pliers! The center pin rarely gets the contact it needs in my opinion, that's why I'm tempted to solder one end.