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Decent RCA connectors ?


kenwstr
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Having some 30 years managing and maintaining a church PA, I have made up more than a few of pro interconnect cables.  By "PRO" I mean balanced.  A basic criteria I look for in connectors is that the cable solders directly the the contact pin or socket, so there are not riveted or pressed surface that can come loose, oxidise, corrode etc to cause intermittent & reliability issues.  This is usually the case with XLR connectors where I usually use either Neutrik or Amphenol,  but not so with Phone TRS, except for Neutrik alone as far as I know.

 

However, I am currently setting up to do some recording at home using a PreSonus interface.  For recording from SE analogue, I am taking RCA into an existing Essence HDACC and XLR from there to the interface, because the interface doesn't support SE connection.  So, this is a way of using what I already have to cleanly convert from SE to MP signal.  Both devices set on 0 dB brings the signal through clean and at an unaltered level so, I can maintain unity gain structure right from the source through the signal chain, minimising S/N.

 

I bought some Canare GS6  for the interconnect cables and some Amphenol ACPR connectors.  However, I am not totally happy with these connectors.  While the signal connects directly to the RCA pin (good) the shield does not connect directly to the RCA ground contacts.  It's obviously a separate solder tab and of different metal type, so possible galvanic issues leading to future reliability issues.

 

Alternatively, the Neutrik NYS series initially seem much better in this regard, when I zoom in on online images,  I can clearly see that the solder tab is not the same piece of metal as the actual ground contacts.  It is however at least the same type of plating.  Image can be zoomed on the Element 14 website. https://au.element14.com/neutrik/nys373-9/plug-phono-white/dp/5008505?st=neutrik rca

5008505-500.jpg

 

I do not know if the Neutrik Pro series are any better in this regard as they appear to have a telescopic function to ensure the ground connects first to prevent pops when plugging/unplugging while live (who would do that at home?).  That telescopic movement suggests there is not a direct connection.  Of course these (PRO) plugs cost 10 times more.  That's over $100 (bulk price) per stereo channel just for the plugs.  That's the biggest domestic to pro mark-up I've ever seen.  I think it's pretty rude & I'm not inclined to support that sort or attitude, especially if I can't verify that both shield and signal solder directly to the actual contacts because that is really the simplest and most basic criteria for reliability.

 

So, that's my rant (sorry)  but can anyone help me out by identifying an RCA connector that does actually fulfil this criteria?

 

Ta, Ken

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Not sure if these meet your criteria, @kenwstr, but I use Vampire 557 RCA plugs - as they are pretty much minimal mass, as well as being robust & easy to use.

 

See here:  www.vampirewire.com/product-page/557

 

Andy

 

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The NYS373 connectors are manufactured in one piece, it's just that the ground tab is then folded back and pressed in so it looks like a press fit from the outside, the inside and edge of the tab shows it is continuous.

 

Might be able to see it in this picture.

 

There are some cheaper solid machined RCAs out there, but you might have to go to ebay for them and try a few different ones.

Personally at home I use Starlines, which are essentially an ETI clone and can be had for a couple of dollars each but only if you buy a lot of them.

 

EDIT: just looking closer at the thing, I think it might be the ground tab is stamped with an annulus hanging off it, which is then folded and pressed in to the body, held in by the rolled edge. I suspect that is how it was manufactured, the body is machined but the ground tab is stamped, folded, then crimped into place.

RCA1.jpg

Edited by GaryT
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6 minutes ago, davewantsmoore said:

No the perfect choice of cable.... but that ship has sailed.

I would go:  https://au.rs-online.com/web/p/coaxial-cable/1876102/

 

 

Use crimp style connectors designed to fit your cable.

https://www.ambertech.com.au/conn-rca-crimp-to-suit-gs-6

... but you will need a tool, which if it's only for a couple cables, will make it expensive.

 

I can tell you that the tool for GS6 crimp RCAs is $400 and only works for those RCA, plus a small number of 50 ohm RF connectors that wouldn't be of any use.  You CAN fudge it with certain RG58 crimpers though, that's very cheap but you need to take the leap of faith and test it, which means potentially destroying some connectors since they aren't re-usable.

 

Also, what are your thoughts behind 1855A being perfect for analogue? is it the solid core you prefer? lower inductance? 

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While they are a bit pricy they are rugged, and used by some hi-fi brands (Nordost for example). in a pro environment grounding first and last is important in minimizing pops and clicks in patching. that said, RCA live patching isn't particularly common.

 

However, I think Ken is looking for a connector with a one piece solid design, and the pro-fi RCAs have a sliding mechanism that cant be made in a single piece.

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I second the Starline connectors GaryT suggested. Tellurium copper base metal contacts with a choice of gold or silver plating. They are  manufactured by the same Taiwanese factory that makes the KLEI and ETI bullet connectors. $15 - $20 per set (4) on Ebay or AliExpress.

 

Edited by Weka
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18 minutes ago, GaryT said:

While they are a bit pricy they are rugged, and used by some hi-fi brands (Nordost for example). in a pro environment grounding first and last is important in minimizing pops and clicks in patching. that said, RCA live patching isn't particularly common.

 

However, I think Ken is looking for a connector with a one piece solid design, and the pro-fi RCAs have a sliding mechanism that cant be made in a single piece.

 

Correct, 1 piece connection is what I am looking for.

I have been reading replies and considering all comments.

For the actual patch between the HiFi and recording system (computed desk on wheels), it's likely I'll be plugging & unplugging more frequently.  Maybe the Pro ones are appropriate just for this 1.5m patch cable.  It may be kinder to the equipment at each end.

 

Expensive though!

 

Ken

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4 hours ago, GaryT said:

The NYS373 connectors are manufactured in one piece, it's just that the ground tab is then folded back and pressed in so it looks like a press fit from the outside, the inside and edge of the tab shows it is continuous.

 

Might be able to see it in this picture.

 

There are some cheaper solid machined RCAs out there, but you might have to go to ebay for them and try a few different ones.

Personally at home I use Starlines, which are essentially an ETI clone and can be had for a couple of dollars each but only if you buy a lot of them.

 

EDIT: just looking closer at the thing, I think it might be the ground tab is stamped with an annulus hanging off it, which is then folded and pressed in to the body, held in by the rolled edge. I suspect that is how it was manufactured, the body is machined but the ground tab is stamped, folded, then crimped into place.

RCA1.jpg

Ta, perhaps I should buy just some & see for myself.

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5 hours ago, andyr said:

Not sure if these meet your criteria, @kenwstr, but I use Vampire 557 RCA plugs - as they are pretty much minimal mass, as well as being robust & easy to use.

 

See here:  www.vampirewire.com/product-page/557

 

Andy

 

Ta I appreciate the suggestion to go compact.

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8 minutes ago, GaryT said:

Happy to send you a few as samples mate.

Oh Hi, I'm loving that GS6 cable, so expressive and detailed.  Top end is crystal!

Was listening to Loreena McKennitt over it today.   Really nice!

 

OK Gary, email me what you have in mind exactly.

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6 hours ago, GaryT said:

I can tell you that the tool for GS6 crimp RCAs is $400 and only works for those RCA

Yep.... I wouldn't fudge it either.   A bad crimp is like using spit and sticky tape to put the end on.

 

6 hours ago, GaryT said:

Also, what are your thoughts behind 1855A being perfect for analogue? is it the solid core you prefer? lower inductance? 

I'm not sure that solid vs stranded matters as much as some say.

 

GS6 is high capacitance cable.   For a audio cable like this, the dominant parameters are capacitance and shielding (inductance doesn't matter within reason).    The 1855A is something like 50pF/m .... where as the GS6 is much much higher.... which is mostly irrelevant for an instrument (which this cable is designed for).

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On 12/10/2021 at 6:02 PM, davewantsmoore said:

Yep.... I wouldn't fudge it either.   A bad crimp is like using spit and sticky tape to put the end on.

 

I'm not sure that solid vs stranded matters as much as some say.

 

GS6 is high capacitance cable.   For a audio cable like this, the dominant parameters are capacitance and shielding (inductance doesn't matter within reason).    The 1855A is something like 50pF/m .... where as the GS6 is much much higher.... which is mostly irrelevant for an instrument (which this cable is designed for).

 

No doubt you are correct in a theoretical sense where all other parameters are kept constant & only the one under discussion is variable.  This is the only way to test & analyse effects in a scientific or engineering sense, but capacitance is only one of 3 co-dependent properties of cable impedance.

 

Impedance is known to cause frequency dependant attenuation.  The cable you suggest has low capacitance but high DC resistance.  The one I chose primarily for an instrument cable (for recording purposes), as well as testing as interconnects appears to be the opposite way around.  Though I have seen it advertised as low capacitance (figures not stated).  So far today, I have made a pair or 55cm interconnects.  The low end does not seem affected but the top end is delightfully clear & musically expressive compared to what I had before.  Initially I would agree, it's not a warm cable, but I think it complements Loreena Mckennitt's magnificent voice with astonishing subtle detail that I had previously missed.  Though I haven't done much varied listening time on it yet.

 

Seems to me, objective HiFi interconnect reviews tend to score certain aspects of audio performance higher or lower, with no clear winner in every aspect.  The final choice is ultimately a preferences driven compromise.  I need to do a lot more critical listening before deciding how successful the choice was.  Most of what I purchased will be made into instrument cable.  I only have about 2-3m assigned for interconnect testing.

Edited by kenwstr
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1 hour ago, kenwstr said:

but capacitance is only one of 3 co-dependent properties of cable impedance.

... but it's the only one which (within reason) matters in an audio frequency cable.

 

That being said, any well manufacturerd (highly toleranced) coaxial cable, which has enough sheliding for the environment, will do fine.

 

1 hour ago, kenwstr said:

The cable you suggest has low capacitance but high DC resistance.

The resistance is of no concern.

 

1 hour ago, kenwstr said:

Though I have seen it advertised as low capacitance (figures not stated).

160pF/m.   Quite high.

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8 hours ago, davewantsmoore said:

... but it's the only one which (within reason) matters in an audio frequency cable.

 

That being said, any well manufacturerd (highly toleranced) coaxial cable, which has enough sheliding for the environment, will do fine.

 

The resistance is of no concern.

 

160pF/m.   Quite high.

Yes, I did find that figure on one site, where the formatting was really messed up so I couldn't tell with certainty which heading 160 belonged too as pF/m was part of the heading.  Maybe that's the capacitance value and maybe it isn't.  I could not find it on Canare's site as I don't read Japanese and the cable isn't listed on the US site.  So I don't have manufacturer confirmation.  It may be true, probably is, so what, it's a half metre run (80 pF total) & I'm allowed to try out whatever I want.

 

If capacitance is the only spec that matters, all signal cables would minimise surface area and therefore be the thinnest hair like conductor that could be made.  I only see that in earbuds and lapel or ear worn mics, not interconnects.  I guess minimal surface is what has driven you towards a single solid strand.  Unusual choice but that up to you as my choice is up to me.

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46 minutes ago, kenwstr said:

If capacitance is the only spec that matters, all signal cables would minimise surface area and therefore be the thinnest hair like conductor that could be made.

 

Shielding matters, too, a lot. Also, conductor surface area isn’t the only determinant for capacitance, conductor separation and dielectric material play an important role as well. That’s where coax cables come in.

 

In general, cables that connect to high-ohm loads, like interconnects, should be optimised for low capacitance and good RFI/EMI shielding. Cables that lead into low-ohm loads, like speaker cables, need to be low-resistance and low-inductance.

 

That said, one more thing to be considered for unbalanced interconnects is the ground conductor resistance. It should be small to avoid hum and other mains noise.

 

For a 0.5m cable run I wouldn’t sweat it, I’d mainly look for good shielding and good clearance from power cables.

 

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Agree shielding matters.

 

Of course surface area isn't the only factor but mentioning only one aspect implies that all other factors are held to be equal without explicitly saying so.  I agree with all you have said here. 

 

 It's just that I am objecting to the idea that only 1 thing matters and being a little extreme to demonstrate the problem with that approach.  So thankyou for confirming my point.

 

Regards, Ken

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I tend to think people put too much weight on the capacitance of short cables.  Most Hifi cables are in the 0.5 to 2m range where the capacitances are extremely low. I've used fancy braided cables with capacitances in the 300pf/m range before and they still sound bright and sparkly.

 

GS6 starts to naturally roll off gently at ~50KHz due to L/C low pass filtering, sure, but that is over a long distance. Canares graph ends at 200Khz, because that's as far as they swept it, the cable is 5db down at 200KHz, but that is over 100 Meters. so I think we are fine at the 1m length!

 

If we work out the mathematical equivalent R/C low pass filter of a 1.5m GS6 cable, you'd end up rolling off well into the GHz range, so It's not much of an issue.

 

I haven't tested this but I imagine a cable with a reasonable capacitance could be beneficial in filtering any unwanted high frequency noise from switching power supplies and such, in theory that is a benefit. whether HF noise affects your system audibly is probably very dependent on the amplifier being used though.

 

Edited by GaryT
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9 hours ago, kenwstr said:

Yes, I did find that figure on one site, where the formatting was really messed up so I couldn't tell with certainty which heading 160 belonged too as pF/m was part of the heading.  Maybe that's the capacitance value and maybe it isn't.

It is.

For an instrument cable, the capacitance isn't considered a big deal.

 

9 hours ago, kenwstr said:

I'm allowed to try out whatever I want.

Yes... yes you are.

 

9 hours ago, kenwstr said:

my choice is up to me

Indeed it is.....  did you think otherwise?

 

8 hours ago, Steffen said:

conductor separation 

This.

 

 

8 hours ago, Steffen said:

unbalanced interconnects is the ground conductor resistance

Indeed, it's a good byproduct of hefty shields.

 

8 hours ago, Steffen said:

For a 0.5m cable run I wouldn’t sweat it

Absolutely.... nor would I.    More important than the choice of cable, is the termination (dramatically underestimated factor in cable sound IMVHO).

 

 

9 hours ago, kenwstr said:

If capacitance is the only spec that matters

It is.... capacitance and shielding.

 

Reasonable values of inductance and resistance are inconsequential.

 

9 hours ago, kenwstr said:

, all signal cables would minimise surface area and therefore be the thinnest hair like conductor that could be made.

Most would find this surprising.... but there are exceedingly few coaxial cable which is specifically designed for unbalanced "hifi" audio.

 

What you find is that when you balance the distance between centre and shield, and dielectric, etc...... that this (thinnest to extreme) doesn't happen.   To get a reasonable geometry, about 26AWG is as small practical.

 

9 hours ago, kenwstr said:

I guess minimal surface is what has driven you towards a single solid strand.

No, I don't really think that matters so much..... with the right size (to optimise C, vs thickness and dielectric, etc, and to keep R and L in check) then I think either is ok.

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8 hours ago, kenwstr said:

 It's just that I am objecting to the idea that only 1 thing matters and being a little extreme to demonstrate the problem with that approach.

 

Resistance and inductance are inconsequential.

 

Capacitance is ideally as low as possible.    Shielding should be good for LF (which is contrary to the design of a lot of coax).

 

After this.... you are on the right track that the termination of the connector is of critical importance.

 

7 hours ago, GaryT said:

I tend to think people put too much weight on the capacitance of short cables.  Most Hifi cables are in the 0.5 to 2m range where the capacitances are extremely low. I've used fancy braided cables with capacitances in the 300pf/m range before and they still sound bright and sparkly.

 

It depends on the input/output impedances of the circuits the cable is connecting..... and often any rolloff is miles outside of the audio range, and any distortion induced in the circuit on either end is non-existent.

 

.... so it is likely a non issue.... which is why the cable selected wasn't a "send it back" .... but a "don't worry about that now".

 

7 hours ago, GaryT said:

I haven't tested this but I imagine a cable with a reasonable capacitance could be beneficial in filtering any unwanted high frequency noise from switching power supplies and such

 

If there was such noise ..... the cable C won't likely be a strong enough filter

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Trying to get my head around why 2 conductor coax cables are seen as optimum for small signal audio .  Why isn't it better to separate the signal ground and shielding functions to different wires? ie three conductors with shield going to the chassis and +/- to  the signal circuit?  Or do you use two runs of the co-ax for each channel, which may be the obvious answer 😀

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11 minutes ago, RoHo said:

Trying to get my head around why 2 conductor coax cables are seen as optimum for small signal audio .  Why isn't it better to separate the signal ground and shielding functions to different wires? ie three conductors with shield going to the chassis and +/- to  the signal circuit?  Or do you use two runs of the co-ax for each channel, which may be the obvious answer 😀

what you are suggesting is basic balanced cable,needing a balanced input/output on components and xlr female/male plug using balanced cable,  

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