Now that is a description of a very poor RCA analog interconnect! Not that at 18 inches will it matter much, but at long lengths it could be a big problem.
For a description of good RCA interconnects see:
Subwoofer Cables from Blue Jeans Cable
and
LC-1 Audio Cable Design Notes -- Blue Jeans Cable
What is REALLY IMPORTANT in RCA interconnects is that they are made with a non-magnetic metal. Fit is important too, and surface plating should be gold or rhodium. Silver and copper surfaces tarnish too easily, but of course are wonderful conductor material.
We have had access to really good quality RCA plugs and jacks for the last 35 years. They were originally designed and made in Japan, then the USA, Germany, etc.
While the actual initial design of the RCA jack was pretty cheap and not really suitable for lab work, compared to other connectors, partly because of the poor impedance match-up with common RF cables of 50 or 75 ohms.
We have had access to really good quality RCA plugs and jacks for the last 35 years. They were originally designed and made in Japan, then the USA, Germany, etc.
While the actual initial design of the RCA jack was pretty cheap and not really suitable for lab work, compared to other connectors, partly because of the poor impedance match-up with common RF cables of 50 or 75 ohms.
I talked to Denis Morecroft (DNM) about phono plugs once, his take is the less metal used in their construction the better. He prefers a cheap plastic body with gold plated connections over an expensive one with a large metal body. No explanation was forthcoming but as he is a very highly regarded amplifier builder and I am not, I did at least take note. If anyone's interested in this theory I think he has info on his site, Eichmann have info on their site too but then they are selling plugs based on this same theory, their plugs are not worth the money imo.
There are different philosophies regarding connector construction, but usually copper or brass come out ahead, with silver being an exception. It may well be true that less metal might be better, but I usually stick with good solid connectors from Vampire or some equivalent.
Some folk hate RCA connectors, saying they are a vintage plug nowadays. If I ever build a complete system which I might actually keep, i'd be tempted to use balanced connectors, just for a change 😉
At least with a balanced connector you can separate the screen, and have a pseudo balanced connection, with the signal having a dedicated return. Careful layout can extend this all through the signal path, to the inputs of the active device next in line. The signal and its return have to be routed as a differential pair, and shielded by the local ground, preferably on an inner layer with ground top, bottom and sides to avoid any cross talk.
You can also (if you have the money) create a true! coaxial route, with controlled milling and surface plating it is possible to completely surround a trace with the return (GND), though rectangular/square in shape (JNs view would be appreciated here). Again if you use the correct trace width and copper thickness you can get an almost square conductor.
The pseudo differential signal technique is being used more and more in mill/aero/medical designs where ultimate noise immunity and signal integrity are paramount. it works best with HDI PCB technology as you have complete control over the via spans through the design, avoiding via stubs.
You can also (if you have the money) create a true! coaxial route, with controlled milling and surface plating it is possible to completely surround a trace with the return (GND), though rectangular/square in shape (JNs view would be appreciated here). Again if you use the correct trace width and copper thickness you can get an almost square conductor.
The pseudo differential signal technique is being used more and more in mill/aero/medical designs where ultimate noise immunity and signal integrity are paramount. it works best with HDI PCB technology as you have complete control over the via spans through the design, avoiding via stubs.
It's a way to go, that's for sure. I have tried using the twisted pair in 2 core mike cable to carry feed and return in a pseudo balanced effort using RCA's and having the screen connected to ground at one end only.
Not sure it's worth the effort in the end though and you still have old fashioned RCA phono plugs at each end instead of a modern design like say a speakon balanced plug.
Not sure it's worth the effort in the end though and you still have old fashioned RCA phono plugs at each end instead of a modern design like say a speakon balanced plug.
New to the Group
I am looking for a set of solid silver rca plugs that will not break the bank. My project is a set of interconnects with silver wire, cotton shielded. I will be using 3M embossed copper tape as a shield, a cotton rope as a core, Teflon plumbers tape as a insulator between the shield and the wire, with the plumbers tape over the copper shield. Then I am encasing them with a poly braid. The solid silver wire will be one conductor (+) and one conductor (-) 23 gage. Any help would be appreciated. I have also considered silver plated solid copper RCA plugs as well. To deal with tarnish issues I was going to use DeoxIT Gold 100s.
Suggestions?
Sorry to be late to the party, but having read the whole thread, you might consider WBT-0110Ag.
WBT-USA
I am using the copper version with unshielded twisted pair for my preamp output interconnect.
Speakons are unbalanced connectors for speaker cables.
I use them on my speakers, all my line level connectors are XLR or TRS which are balanced.
Doh, of course they are, I used them with an active sub so I should have thought before typing, anyway I meant to say XLR balanced ... you know what I mean.
As well as getting shielding right, XLRs etc also have proper electrical connections to the pins. Most RCA sockets just use a low pressure touching contact between the pcb leads and the RCA socket outer barrel. This makes using exotic RCA plugs a bit academic for a lot of equipment out there.
It's too common for a tight plug to pull the socket out barrel out when the cable is pulled out
It's too common for a tight plug to pull the socket out barrel out when the cable is pulled out
Well and good, but ask Nelson why he didn't install XLR's on my preamp. (One possible answer is there is no room for XLR sockets on the back panel.)
Probably because they would cause a storm of controversy if your pre was not a balanced output version. Not sure he makes such a thing but convention is a powerful force and if he used XLR's in an unbalanced form it would seriously limit off the shelf cable choices for a start.
Look at the complaints Quad and Naim attracted for using DIN connectors. The DIN connector can be made as a much better connector than the RCA.
Why would that be?
On QUAD 520 amps , Klark Teknik and BSS analogoue crossovers balancing transformers were an optional extra, without them they just put out an unbalanced signal on XLRs. These work with any standard XLR cable.
Which is a good thing because there is no way of telling if the optional 'formers were fitted or not.
To attempt to conflate resistor distortion with cable effects shows a significant lack of understanding of circuit theory, or perhaps a hope that readers will lack this understanding and so not notice the clash.davym said:
Learn about how a potential divider works. Ponder on the relative magnitudes involved when a piece of cable forms one arm, and a typical amp input forms the other. Think about what sort of changes might be needed to become (allegedly) audible, yet remain (allegedly) unmeasurable.
It would be a conductance effect, not capacitance. If you don't know, why are you arguing?
I note that the only attempt so far in this thread to offer a vaguely plausible explanation for the alleged difference in sound of silver cables involves them being inferior to copper, by introducing distortion due to surface corrosion semiconductor threads. I am not convinced, but it is another example of how 'audiophile' 'improvements' can actually be expensive ways of reducing sound system performance.
- Status
- Not open for further replies.