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RCA plugs questions and suggestions?

My post from another thread Christmas last year:

I do not pretend to be an expert of any kind on this subject but a review of the basics is always worth bringing up when questions like this get asked. Given good quality connectors and assembly technique the most important property of unbalanced cables is the resistance of the shield. Why? Because in unbalanced equipment the shield is carrying the signal ground currents and the inter chassis ground currents. Without getting into the math let's just say the lower the resistance of this path the less these two currents interfere with each other. Yielding less hum, buzz and other interference. Remember this type of interconnect came about when HiFi gear consisted of an all in one console that contained the tuner(radio), the TT, the amplifier, speakers and the power supply. Ground connection was common to all these components and interconnects were very short.

So for unbalanced cables I use coax with good shield and keep them as short as possible.
 
KL.... said:
Thank you, @Ropeburn, are you suggesting that the distortion is Contact Pressure not Connector Material. If yes, in this case, how can the Contact Pressure be different, especially as the Connectors look identical with the same Dimensions/Architecture? Yes, in this case, these Connectors are at the Output, although the issue is suggested as Connector Material not Contact Pressure, isn’t it?
  • Version1/Not Recommended (note THD+N, FR, SNR/Multitone considered as excellent)
  • Version2/Recommended (note THD+N, FR, SNR/Multitone considered as excellent)
  • THD+N (High Gain)…. 103/106db (3dB improvement). This can be suggested as significant although many have suggested once better than 100dB (even 95db) that the 3 or 4dB will not be audable, will sound the same, and as such, not significant, haven’t they?
  • FR…. Same, Ruler Flat
  • SNR (Low Gain)…. 17.5/17.5 bits, same, Superb
  • Multitone…. 18/21 bits, both considered excellent. This can be suggested as significant although many have suggested once better than 100dB that the 3 or 4dB will not be audable, will sound the same, and as such, not significant, haven’t they?
  • Crosstalk…. Superb/Superb (even better)
  • THD+N vs Power…. rise in distortion >10watts/rise in distortion >30watts. Yes, (Clearly) Noticeable, isn’t it, although not Dramatic but is it Audable?
Reasonable Question, for this thread…. is the Connector Material change, Audable, especially as the 103/106db THD+N (consensus) suggests that it will not be Audable?
  • For consideration and discussion, for Version 1 where it is Not Recommended…. THD+N/103db, FR/Ruler Flat, SNR (Low Gain) 17.5 bits/Superb (less), Crosstalk/Superb, only THD+N vs Power and Power on/off are (noteable) issue/s. With a THD+N of 103db, the Not Recommended suggests that the indicated issue/s is/are Audable, reasonable….
  • Considering the indicated issue was Output Connector Material, the Power on/off noise is a Conundrum/Dilemma, isn’t it? Perhaps, DC Offset/Chargeing Effect and/or PS Noise/Ripple....
  • View attachment 533102 View attachment 533103
  • Consideration for Vesrion2…. if the Version1 Connector/s were placed after the Version2 Connector/s (if possible), would the Measure/s be the same as/similar to Version1?
Further Question…. if this had occured at the Input, rather than the Output, what would the Measure/s be?…. for consideration and discussion….
Click to expand...
For Consideration and Discussion, with consideration to ClassD, LC output, preFFB/PFFB, Output Connectors/Connector Material, THD+N - 103dB for 1st Version (Not Recommended) and 106db 2nd Version (Recommended)….
  • PFFB is considered Higher Performing than preFFB, why?.... because it includes the the LC process in the GFB/NFB process which can (if possable) correct the non Linearity of the LC process. This implys that the Output Connectors are not included in the PFFB, doesn't it? It was suggested and implyed that the 1st Versions Lesser Performance (3dB less) was due to the Output Connectors/Connector Material, wasn't it? Noteing that the 1st Versions THD+N of 103dB is considered as Excellent (High Performing), which is reasonable, isn't it, it could be suggested (by ASR Consensus) that Version 1 and Version 2 will Sound the same but do they?
    • If they do Sound the same then perhaps no need to improve/change anything, reasonable? A THD+N of 103dB is already considered as Excellent (High Performing), isn't it?
    • If they do Not Sound the same then this could be considered as the effect of the Output Connectors/Connector Material, especially as the Output Connectors are not included in the PFFB, reasonable? This also suggests that the Application of Materials can affect Measure/Performance, Application of PFFB can correct/improve Measure/Performance, but will/do they Sound the same?
    • Note the FR is Ruler Flat for Version 1 & 2, and SNR is the same (High Performing)....
  • Can this also occur at the Input Stage? If the Input Connectors are not included in the Input Stage GFB/NFB (Process/Correction) and/or CMRR (Difference/Differential or SE Input) then the answer can/would be Yes, wouldn't it?
 
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Sokel said:
I usually get a spool of Mogami star-quad and use it everywhere, max length I ever use is 6 meters (3 meters actually, back and forth) and that's for el. measurements, as I like to measure my gear life-like, as they sit on the rack.

That actually coincidentally sees the effect of the long cables as I have compared the results with short ones (long story short, your ADC better have a decent input impedance, as all gear, or... :facepalm: )
Click to expand...
Thank you, @Sokel, Yes, this is the best way to Test/Measure your Connectors/Cable, that is at/after the output of the Device (ie after the PFFB, with a known Test/Measure). These 2 Tests/Measures show this as a good indicator/approach, don't they?

Buckeye 3 Channel Purifi Amp Review.... Not Recommended
Buckeye 3 Channel Purifi Amplifier Review (2nd).... Recommended

The Test/Measure, of the Connectors/Cable, should show the following....
  • Degraded Tests/Measure (as occured above).... not a reasonable choice, for your Device
  • Unchanged Tests/Measure.... reasonable choice, for your Device
  • Improved Tests/Measure (as occured above).... more than reasonable choice, for your Device
As you have mentioned, this can also be done at the Input although the Measure will be at the Output, won't it....
 
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Sorry to keep bringing up Mogami’s molded cables. I have no soldering skills and love excellent quality crimps because of the coolness of cold welding. Usually people are familiar with their Gold Series but the Pure Patch line is perfect for many home audio enthusiasts.

When it comes to RCA plugs my favorite is the humble Rean NYS352. They are compact and durable. The couple of cables I ordered from cable builders use heat shrink for strain relief but they aren’t under a lot of stress around here! In other parts of the world they are branded Yongsheng because they are manufactured in China by a subsidiary of Neutrik. I just discovered that NYS stands for Neutrik Yorkville Sound. Yorkville Sound is a Canadian pro sound company.

www.rean-connectors.com

NYS352 | REAN 6.3mm Stereo Plug Connector

Discover the NYS352, a high-quality 6.3mm stereo plug connector by REAN. Ideal for professional audio applications with durable and reliable performance.
www.rean-connectors.com www.rean-connectors.com
 
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wadude said:
When it comes to RCA plugs my favorite is the humble Rean NYS352.
Click to expand...
They are very solid and with heat shrink under the case a nice fit for the cable.

I ran into issues with their fit on certain devices over the years. All old stuff from the phono section. Ended up un-soldering a dozen and replacing them. But I never had any issues on other devices. I often see them among the most cost-effective choices.
 
Ruediger said:
They are very solid and with heat shrink under the case a nice fit for the cable.

I ran into issues with their fit on certain devices over the years. All old stuff from the phono section. Ended up un-soldering a dozen and replacing them. But I never had any issues on other devices. I often see them among the most cost-effective choices.
Click to expand...
Surprisingly I had the same issue with too loose of fit with Switchcraft RCA plugs on my Dynaco MKIV mono blocks. I mean, who would have thought?!
 
wadude said:
Surprisingly I had the same issue with too loose of fit with Switchcraft RCA plugs on my Dynaco MKIV mono blocks. I mean, who would have thought?!
Click to expand...
In the olden days, loose ground connectors on "RCA plugs" were easily snugged up, prior to connection, by a gentle squeeze with a sensitive, caring pair of pliers. ;)

Some plugs had a split center pin that could be spread a bit with a jeweler's screwdriver. Others had springy strips as part of the pin to provide a snug fit.
 
mhardy6647 said:
In the olden days, loose ground connectors on "RCA plugs" were easily snugged up, prior to connection, by a gentle squeeze with a sensitive, caring pair of pliers. ;)

Some plugs had a split center pin that could be spread a bit with a jeweler's screwdriver. Others had springy strips as part of the pin to provide a snug fit.
Click to expand...
1781185979582.jpeg

Years ago I found a seller on eBay that packaged these 3 foot molded cables at five for $5.00. They are branded Video Runners and are Mogami W2964 with the nickel plated ground connectors as you describe. As a vintage high hifi enthusiast they really float my boat.
 
babadono said:
Curious why some of you use balanced cable (2 conductors + shield) for unbalanced cables. Just what you have laying around?
Click to expand...
I solder +ive and -ive wires, plus sheild to negative at source end only, floating sheild at receiving end. I don't really know why. Likely the 1st instructional video I found on YouTube all those years ago. I've always done them this way, looks to work fine. I'm interested why I do this.
 
what is +/- ive? On an unbalanced interconnect you don't tie the ground/shield at both ends? How does that work? Are the grounds tied together through the earth connection on the power cords?
 
Jeff M. said:
I know there is a lot of info on RCA connectors out there on the internet. I know most of it is hog wash. Has there been any research or test done on RCA plugs? Thanks for everyone’s help and advice. Jeff
Click to expand...
Hi, @Jeff M.
This venture would end-up like putting lipstick on a pig >no dis<! :rolleyes:
I mean, after all, they are just RCAs and single-ended, so why even bother?
 
Crook said:
I solder +ive and -ive wires, plus sheild to negative at source end only, floating sheild at receiving end. I don't really know why. Likely the 1st instructional video I found on YouTube all those years ago. I've always done them this way, looks to work fine. I'm interested why I do this.
Click to expand...
So far as I know it has no benefit, and is a suboptimal use of that cable if it's the only bit of cable you have. My guess is someone was looking for a marketing gimmick and came up with some spurious explanation for it with some half-truths in there for good measure, and people have copied it since. I know Monster used to sell one like that with a direction marked on the cable, but don't know whether they were the first.

Disconnecting the shield at the receiving end is something that's sometimes done with balanced cables to break a ground loop with a device with a 'Pin 1 Problem'. Maybe that's where they got the idea from.

For the technical details see Jensen Transformers' AN007 - section 2.9 on page 20 for single ended cables and section 3.6 on page 27 for why to disconnect at the receiving end, plus much more in the rest of it.
 
somebodyelse said:
So far as I know it has no benefit, and is a suboptimal use of that cable if it's the only bit of cable you have. My guess is someone was looking for a marketing gimmick and came up with some spurious explanation for it with some half-truths in there for good measure, and people have copied it since. I know Monster used to sell one like that with a direction marked on the cable, but don't know whether they were the first.

Disconnecting the shield at the receiving end is something that's sometimes done with balanced cables to break a ground loop with a device with a 'Pin 1 Problem'. Maybe that's where they got the idea from.

For the technical details see Jensen Transformers' AN007 - section 2.9 on page 20 for single ended cables and section 3.6 on page 27 for why to disconnect at the receiving end, plus much more in the rest of it.
Click to expand...
So only connecting the shield at one end is called ‘telescopic’ shielding and can have advantages in noisy RF environments where you also have the possibility of ground loops. In general it doesn’t matter which end is connected to ground as long as one is.

Where it does matter is where the equipment attached to one end is itself not earthed for example connecting an electric guitar to an amp is the obvious example.
 
Gee, I hadn't thought about ‘telescopic’ shielding cables in several decades.
It requires a bulk cable with two copper braided shields, insulated from each other.
The inner shield is attached to XLR pin 1 at both ends.
The outer shield of a interconnect cable is only attached to XLR pin 1 at the send end.
While with a mic cable the outer shield is only attached to XLR pin 1 at the pre-amp end.
* * * * * * * * *
A more modern solution is to use a StarQuad cable.
 
I guess I am still not understanding.......in unbalanced interconnections(RCA) the ground or shield or whatever you want to call it is the return path for the signal current. If not connected in even a sneaky or not straight forward way the interconnect will not work. Or have you guys broken through the laws of physics into a new dimension?
 
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