Calling all digital cable experts - SPDIF termination question

[Mike]

I'd suggest that although we all use them, any phono plug is inferior to almost any connection you can make short of a quick twist of two wires & a bit of insulating tape!

You can put all the locking devices, exotic metallurgy, solder & crimping you like into them, but you're just polishing the turd of a fundamentally bad design.

Excellently put!

[Dave Cawley]

What is wrong with them?

Dave

[Marco]

I'd suggest that although we all use them, any phono plug is inferior to almost any connection you can make short of a quick twist of two wires & a bit of insulating tape!

Indeed

If only we could hard-wire our whole hi-fi system from start to finish!

Marco.

P.S Banana plugs on speaker cables are just as bad, but of course practicality and convenience naturally win the day.

[Mike]

What is wrong with them?

Dave

Erm... they're shite!

[Mike]

Sorry Dave,

That was a bit, err, blunt!

Now, not for a minute am I calling your technical expertise into question, but... I'm a little bit surprised by the question, I thought you were a bit cleverer than that! .

Let's start with the simple things, first of, physically it 'makes' signal before screen, and breaks screen before signal.

Not great!

Next?

[alb]

That only really applies / seems to work if using phono's. With 75R BNC and a good RG6 cable you can choose what length you want...within reason.

I didn't know that!
But then again, there are many things i don't know.
I have to admit that i can't hear any difference between one metre BNC leads and any other short length.
I was just playing safe.

[Mike]

The answer to your second question may not be so firm, I'm sure STan or Dave can shed some insight here but without being able to see what the effect would be of a direct cable to PCB track solder connection via a TDR (Time Domain Reflectometer) I think the result would be very hit or miss.

I've never used a TDR with sufficient resolution that could differentiate a few mm of pcb track!... got any pointers?

I use these things very regularly. Admittedly, mostly OTDR's... but I'd still be interested.

Cheers...

[Dave Cawley]

I thought you were a bit cleverer than that! What, because I asked a question!!!!!!

physically it 'makes' signal before screen, and breaks screen before signal. No, I'm not being funny here, I don't see that as a technical issue? But I am interested in why people think they are a problem?

On all the digital stuff I have here, the manufacturers fitted BNC's as standard on the digital bits and XLR's for balanced audio.

Regards

Dave

[Marco]

Surely the most obvious explanation why any form of connector is poorer than hard-wiring is because every time you introduce another interface into the chain the signal is broken? In connections where electricity is being passed, this raises resistance - always a no-no; hence why hard-wiring is often the preferred route.

Or are we discussing something else?

There's a very good reason (as mentioned) why people hard-wire circuits in valve amps, as opposed to using PCBs, and also for example why I've hard-wired mains leads directly into the MCBs of the dedicated consumer unit powering my hi-fi system

IECs, phonos, BNCs, DINs, XLRs, bananas, 13A plugs, fuses, - they're all 'shit', some more so than others. But it's unfortunately "shit" most of us have to put up with.

Marco.

[Mike]

I thought you were a bit cleverer than that! What, because I asked a question!!!!!!

physically it 'makes' signal before screen, and breaks screen before signal. No, I'm not being funny here, I don't see that as a technical issue? But I am interested in why people think they are a problem?

On all the digital stuff I have here, the manufacturers fitted BNC's as standard on the digital bits and XLR's for balanced audio.

Regards

Dave

Perhaps the 'manufacturer' also thinks phonos are shite then?

They were designed back in the 40's, mainly to be cheap I reckon. Though, as usual, the audio industry has found ways and means to make them expensive!

They're just poor, and well past their 'best before date'.