Changing from an optical cable to a coax cable?

[andyr]

I wondered if anyone here has done a straight swap ... and what their opinion is of the result?

 

I’ve just changed the cable which goes from my 4-way digital source selector into my miniDSP unit, from optical to coax (RCA).  Sitting down to listen to a CD I know well (Fat Freddy's Drop "Based on a True Story") ... I am flabbergasted by how much my system is sounding better - in fact, very much improved.      Bass extends deeper and seems fuller - and transients are more incisive ... and that's for a start!  

 

Who would've thunk it would make that much difference?  (Although to be fair, I understand it is not the optical cable itself which degrades the signal - it's the poor-quality optical-to-copper converters used at either end which are the culprit.  It seems that no-one makes high-quality converters.    )

 

 

Regards,

Andy

[Hydrology]

Implementation seems to be the key here for which one performs better. One would assume optical is immune to RF noise, but the conversion process can undo all that.

[andyr]

8 minutes ago, Hydrology said:

Implementation seems to be the key here for which one performs better.

 

Of course, H - and unfortunately ... implementation trumps theory every time!  

 

8 minutes ago, Hydrology said:

One would assume optical is immune to RF noise,

 

Not only that - it provides galvanic isolation (which can prevent ground-loop hum).  

 

8 minutes ago, Hydrology said:

but the conversion process can undo all that.

 

And that's where the rubber hits the road!    AIUI - unlike just about any thing else used in hifi equipment (capacitors, wire, resistors, connectors) ... there are no makers of quality optical-to-copper converters.  There are only a few makers of cheap o-t-c converters ... which everyone (whether hi-end or low-end) must use.  

 

I posted bcoz I was interested to know whether anyone else had found such a great improvement, going from an optical interconnect to a copper digital interconnect.

 

Andy

 

[stereo coffee]

Hi Andy

Actually the opposite, I stumbled across a optical cable that is IMO better than coax. It uses a braid over its entire length.

 

Cheers  /  Chris  

 

 

 

[muon*]

In the disk spinners I have owned that have had both optical and coax, the coax connection sounded much better every time in every one of them.

[Bunno77]

Shows how important experimenting is in the Hifi world.

Unfortunately we don't all have access to heaps of equipment but many would benefit from more experimenting

[bob_m_54]

47 minutes ago, stereo coffee said:

Hi Andy

Actually the opposite, I stumbled across a optical cable that is IMO better than coax. It uses a braid over its entire length.

 

Cheers  /  Chris  

 

 

 

So what do you think the braid over an optical cable achieves?

[stereo coffee]

5 minutes ago, bob_m_54 said:

So what do you think the braid over an optical cable achieves?

Well obvious is better sound quality, some of the best I have ever heard.   Less obvious is exactly why. I will need to disassemble one, to arrive at a possible answer for you.

 

 

[andyr]

1 hour ago, stereo coffee said:

Hi Andy

Actually the opposite, I stumbled across a optical cable that is IMO better than coax. It uses a braid over its entire length.

 

Cheers  /  Chris  

 

How very interesting, Chris - as optical cable is supposed not to suffer from RFI ingress.  (Which an earthed shield prevents.)  And how does the braid get earthed, given the optical connectors at each end?

 

I'd be interested in buying one - just to see if I get the same thing in my system.  Can you provide a link?

 

Andy

 

[stereo coffee]

1 minute ago, andyr said:

 

How very interesting, Chris - as optical cable is supposed not to suffer from RFI ingress.  (Which an earthed shield prevents.)  And how does the braid get earthed, given the optical connectors at each end?

 

I'd be interested in buying one - just to see if I get the same thing in my system.  Can you provide a link?

 

Andy

 

Hi Andy

Its a 2metre cable made by EMK with a part number EMK019-002. I obtained the 10 cables I have from eBay.   

[stereo coffee]

14 minutes ago, andyr said:

 

How very interesting, Chris - as optical cable is supposed not to suffer from RFI ingress.  (Which an earthed shield prevents.)  And how does the braid get earthed, given the optical connectors at each end?

 

I'd be interested in buying one - just to see if I get the same thing in my system.  Can you provide a link?

 

Andy

 

Likely not earthed directly,  rather if we think of earthing then it may, ( or may not ) fall under loose classification of offering a Faraday shield of sorts.  Faraday shields are explained here.  

https://en.wikipedia.org/wiki/Faraday_cage

 

Then again I know with the parts I use,  there are very unique relationships, to semiconductors where light is used. I need to disassemble a cable to begin putting my finger on,  what it might be doing so well.

 

[bob_m_54]

1 hour ago, andyr said:

 

How very interesting, Chris - as optical cable is supposed not to suffer from RFI ingress.  (Which an earthed shield prevents.)  And how does the braid get earthed, given the optical connectors at each end?

 

I'd be interested in buying one - just to see if I get the same thing in my system.  Can you provide a link?

 

Andy

 

It doesn't, fibre optical data transmission is immune to RFI/EMI

[stereo coffee]

 

2 hours ago, bob_m_54 said:

It doesn't, fibre optical data transmission is immune to RFI/EMI

 

If it was just red light spectrum itself with no other materials involved, we would indeed have less to consider, but that is not the case with many forms of cable construction materials and lengths.  We can see the influence of different materials being used  in a 2008 document produced by Toshiba that  change permissible data rates upward with certain better construction. Page 3 as example shows a sheathing.

 

I also like to keep in mind the work of Hendrik Lorenz   https://en.wikisource.org/wiki/Electromagnetic_phenomena

& particularly his first paper at Reference 4  https://en.wikipedia.org/wiki/Hendrik_Lorentz

 

We can see evidence of particle theory allowing visibility of influence of magnetism ,  under certain set conditions. 

 

 

 

Fiber-Optic Devices TOSLINK.pdf

[Ittaku]

Those explanations sound far fetched to me. The most likely explanation is simply a better connector at the end of the cable. The toslink connector is not the best design in the world.

[sir sanders zingmore]

4 hours ago, stereo coffee said:

 

 

If it was just red light spectrum itself with no other materials involved, we would indeed have less to consider, but that is not the case with many forms of cable construction materials and lengths.  We can see the influence of different materials being used  in a 2008 document produced by Toshiba that  change permissible data rates upward with certain better construction. Page 3 as example shows a sheathing.

 

I also like to keep in mind the work of Hendrik Lorenz   https://en.wikisource.org/wiki/Electromagnetic_phenomena

& particularly his first paper at Reference 4  https://en.wikipedia.org/wiki/Hendrik_Lorentz

 

We can see evidence of particle theory allowing visibility of influence of magnetism ,  under certain set conditions. 

 

 

 

Fiber-Optic Devices TOSLINK.pdf 852.73 kB · 0 downloads

That gif is fun to watch. But how is a  bending electron beam relevant to the discussion?

[stereo coffee]

1 hour ago, sir sanders zingmore said:

That gif is fun to watch. But how is a  bending electron beam relevant to the discussion?

It was very briefly showing particle physics has different explanation.  Glad you enjoyed it 

[bob_m_54]

6 hours ago, stereo coffee said:

 

 

If it was just red light spectrum itself with no other materials involved, we would indeed have less to consider, but that is not the case with many forms of cable construction materials and lengths.  We can see the influence of different materials being used  in a 2008 document produced by Toshiba that  change permissible data rates upward with certain better construction. Page 3 as example shows a sheathing.

 

I also like to keep in mind the work of Hendrik Lorenz   https://en.wikisource.org/wiki/Electromagnetic_phenomena

& particularly his first paper at Reference 4  https://en.wikipedia.org/wiki/Hendrik_Lorentz

 

We can see evidence of particle theory allowing visibility of influence of magnetism ,  under certain set conditions. 

 

 

 

Fiber-Optic Devices TOSLINK.pdf 852.73 kB · 1 download

see my previous post...

[stereo coffee]

2 minutes ago, bob_m_54 said:

see my previous post...

and my subsequent post.

[sir sanders zingmore]

34 minutes ago, stereo coffee said:

It was very briefly showing particle physics has different explanation.  Glad you enjoyed it 

It’s misleading though. 
It’s as misleading as implying that optical cables need to be shielded from gravity (it bends light too after all)

[bob_m_54]

https://www.prysmiancable.com.au/documents/optical-ground-wire.pdf/

 

https://en.wikipedia.org/wiki/Optical_attached_cable

 

https://www.vialite.com/resources/guides/what-is-rf-over-fiber-technology/

 

https://micronor.com/why-fiber-optic/

Edited August 14, 2021 by bob_m_54

[sir sanders zingmore]

1 hour ago, bob_m_54 said:

https://micronor.com/why-fiber-optic/

 

 

High EMI/RFI

Fiber optics is immune to any electrical interference. If the concern is EMI/RFI interference, then fiber optics is the only choice.

 High Magnetic Fields

Fiber Optics is immune to any magnetic interference. Deployment within electrical motors, transformers or MRI bore will not affect the optical signal.

 

[Anthony1]

S/PDIF (RCA Coax) via 75 Ohm cable can sound fantastic.
And for too long I thought it would be a lesser format compared to AES/EBU. Optical has obvious limits in my experience (but didn’t use a megabuck cable). 
The S/PDIF breakthrough came when a CrystalCable digital cable 75 Ohm was installed, superb sound. 
In summary I’m not surprised andyr also found the S/PDIF can sound great. 

[Addicted to music]

On 13/08/2021 at 5:17 PM, andyr said:

 

 

Who would've thunk it would make that much difference?  (Although to be fair, I understand it is not the optical cable itself which degrades the signal - it's the poor-quality optical-to-copper converters used at either end which are the culprit.  It seems that no-one makes high-quality converters.    )

 

 

Regards,

Andy

Optical cables can be physically compromised, alway make sure they solidly clip in on the ends as this is the week point.   To check whether a optical cable is working  shine  both ends at a light source and ensure that the light intensity are identical out of each ends, if one end is brighter than the other it’s faulty.