RCA vs BNC

Hi-Fi Corner
1

Morning Peeps

So after some advice from the hood people on these pages I’m going to convert the RCA plugs on my Rega P6/Ania to BNC to fit my Nac 72.

I had some 50ohm Items knocking around which were rated for RG179 wire gauge. This is way to thin (looks to be about 0.5mm or so) so am wondering if the best way forward is to snip the RCA conector off the Rega leads, strip it back and then measure the core so I’ll have an accurate idea of the width to go for in the BNC…if I can find a good conversion table!

Clive

2

Either that, or see if you can access the other end:

Might be less destructive and you could potentially opt to use a different cable altogether.

3

I fitted BNCs to replace phonos using standard RG58 BNCs, these fitted well enough and I was able to get the centre conductor, in its insulator, to fit inside the metal ‘top hat’ piece that the shield connects to.

Also… Isn’t RG179 a 75Ohm cable?

4

Thanks for that Stephen. Was that the solder on type? Can you remember where you purchased them?

Clive

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They were solder on ones that I had bought from RS about 30 years ago…

I’ve just searched on the RS website (RG58 plus BNC) and they are still selling them under the RS Pro brand.

Not sure if I should post the part number, so I won’t but it’s easy to find.

6

Many thanks Stephen.

How thick was the core of the RCA wire?..looks very hard to get into the hole in the brass core bit!

Clive

7

I don’t remember, I’m afraid. I think I tinned it and then clipped/filed it to fit before soldering.

I don’t recall it being that complicated (although it was something like five years ago)

8

OK, thank you.

9

It is indeed, terminating with 50 ohm terminators will lead to a sub optimal/poor performance cable… depending on application introducing losses and/or reflections.

10

Hi Simon

I was referring to the thickness of the wire, not the type. I’m just trying to get a bnc connector with the widest receptical for the rca lead.

Clive

11

Just in case there’s any confusion here, the BNC sockets used for the Phono inputs on Naim pre-amps and phono stages are 50 ohm, therefore you should use 50 ohm BNC plugs.

1 Like
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Yep, 50ohm all the way Richard.

13

Indeed, I think the 75 Ohm spec applies more to the SPDIF cables.

14

And FM aerial downleads and satellite dish LNB feeds… and don’t let’s forget video leads.

15

HDMI cable is balanced , on 100 ohm impedance twisted pairs.

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