I am collecting parts and getting ready to build a whole new system for my "office" when I finally get round to moving all the crap out of the room and re-decorating.
I'm eventually making everything but the TT, a valve phono pre, a Raspberry Pi based digital source, a Tube pre and a Gainclone power amp.
I'm just getting around to purchasing some RCA connectors and I had a thought.
I'm a CCTV/video system engineer and I mainly work on very large interconnected systems. Untill a few years ago it meant miles of RG59 75R coax and hundreds sometimes thousands of BNC connectors couplers, These day's it mainly means IP network based systems, Cat6 and RJ45s. This means in my shed and attic I have a load of very nice BNC/RG59 parts that will probably never get used in a video system now.
Any good for audio? I could probably lay my hands on a fair few BNC Bulkhead connectors soon too.
I've always thought the BNC was a nice connector and the RCA is a bit shoddy by comparison.
Not sure how the 75R impedance of the coax would effect the phono/line level signals in practice though. would it matter with the high input impedance of audio kit?
What do you think?
I'm eventually making everything but the TT, a valve phono pre, a Raspberry Pi based digital source, a Tube pre and a Gainclone power amp.
I'm just getting around to purchasing some RCA connectors and I had a thought.
I'm a CCTV/video system engineer and I mainly work on very large interconnected systems. Untill a few years ago it meant miles of RG59 75R coax and hundreds sometimes thousands of BNC connectors couplers, These day's it mainly means IP network based systems, Cat6 and RJ45s. This means in my shed and attic I have a load of very nice BNC/RG59 parts that will probably never get used in a video system now.
Any good for audio? I could probably lay my hands on a fair few BNC Bulkhead connectors soon too.
I've always thought the BNC was a nice connector and the RCA is a bit shoddy by comparison.
Not sure how the 75R impedance of the coax would effect the phono/line level signals in practice though. would it matter with the high input impedance of audio kit?
What do you think?
RG-59 runs at about 16pF/ft. This is the number you need to know for loading of pre-amp outputs...less than 50ohm coax so that is a plus.
You are at such a short wavelength the 75ohm part you don't need to worry about.
It will work fine for single ended applications.( not so sure of Phono cartridge impedances)
If your BNC's are 75ohm BNC's then watch out for trying to mate with 50 ohm BNC's...bit of a difference physically.
I would only be concerned with compatibility with anything else you wanted to hook up.
Suggestion: Make a few adapters: BNC/RCA, BNC/3.5mm stereo, 75R BNC/50R BNC (for signal generators/scopes, etc.
My thoughts.
You are at such a short wavelength the 75ohm part you don't need to worry about.
It will work fine for single ended applications.( not so sure of Phono cartridge impedances)
If your BNC's are 75ohm BNC's then watch out for trying to mate with 50 ohm BNC's...bit of a difference physically.
I would only be concerned with compatibility with anything else you wanted to hook up.
Suggestion: Make a few adapters: BNC/RCA, BNC/3.5mm stereo, 75R BNC/50R BNC (for signal generators/scopes, etc.
My thoughts.
"75R impedance" for a cable or connector is meaningless at audio frequencies. That is the RF impedance. All audio needs in a connector is a good low resistance connection at the mating surfaces, plus (for unbalanced connections) 'ground mates first'. A good RCA provides the former (not all are good!) but not the latter. BNC should provide both.JammyBStard said:
Naim use BNC for phono so I wouldn't worry. Now you may have copper plated steel core cable rather than copper cored. If so depends if your audiophila nervosa will cause you a problem with that.
Personally I love BNC
Personally I love BNC
The BNC is nice and good enough for all audio, both analogue and digital.
The HF in digital does need the RF characteristic of the connections. Use the 75ohms BNC if you have them to match the 75ohms cable.
If you only have 50ohms BNC (unlikely for video), then buy 50ohms cable.
I am told that for our short lengths, that a mismatch of 50 to 75 cable to plug or plug to cable does not make much difference to our HF signal quality .
As DF says impedance mismatch makes absolutely no difference to analogue signal quality.
My Sugden CDP uses 75ohms BNC for the transport to DAC connection.
My scope uses 50ohms BNC for all the inputs/probes/cables.
The HF in digital does need the RF characteristic of the connections. Use the 75ohms BNC if you have them to match the 75ohms cable.
If you only have 50ohms BNC (unlikely for video), then buy 50ohms cable.
I am told that for our short lengths, that a mismatch of 50 to 75 cable to plug or plug to cable does not make much difference to our HF signal quality .
As DF says impedance mismatch makes absolutely no difference to analogue signal quality.
My Sugden CDP uses 75ohms BNC for the transport to DAC connection.
My scope uses 50ohms BNC for all the inputs/probes/cables.
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I'll have to have a good rake through the shed. As you say, for video it It will all be 75ohm.
Thanks all
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Thanks all
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