Audio cable topologies used for SE interconnect cables

[Alrainbow]

https://youtu.be/QOagVDZLQnA
How many times stuff just don't sound good we call it bad synergy lol
there are many reasons why and this can be just one of them.
A simple iso can solve this. Does anyone know other ways or have stories to tell.

[joeinid]

That’s very interesting, didn’t realize about the RCA differences vs amps used. I’m curious now about what mine are and what I should be using with them.

Thanks!

[Alrainbow]

I always knew of this due to my Electronic background but to know what preamp and or amps use it is key. Mark Levenson does it's why I posted it. I must use there cables or a in line iso transformer to maintain the sysnergy
even my no 33 amps say it on the back of the amps. Same with speaker outputs of them.
I feelnwe need a list of who uses this.
And lastly this. Of all the high end cable makers does anyone make them. Does any one even know it exists lol.

[Alrainbow]

https://www.eetimes.com/document.asp?doc_id=1274958
just to make it more complex he says this but did not explain its effects

[Speedskater]

In the youtube at about 3:30 minutes in, he neglects to point out that the signal is also on the shield. In an unbalanced interconnect, the center conductor is the SEND and the shield is the RETURN. Also he only covered radiated noise, he never got to the other big problem, Common Impedance Coupling Noise currents.

The engineering paper is about a sensing and switching circuit for manufactured products. More of a problem in portable units than in hi-fi systems.

[Alrainbow]

http://electriciantraining.tpub.com/...lifier-101.htm

http://www.ti.com/lit/an/sloa054e/sloa054e.pdf

http://electriciantraining.tpub.com/...lifier-101.htm

[Speedskater]

Yes, those are three nice engineering papers on circuit design.
Not too much fun for the average hi-fi audiophile.

[alp-tone]

In the youtube at about 3:30 minutes in, he neglects to point out that the signal is also on the shield. In an unbalanced interconnect, the center conductor is the SEND and the shield is the RETURN...

+1

A shield, connected at both ends, conducts a current which contains both the (-) audio signal and any EM/RF interference. This is one reason many have employed the topology of a twisted-pair conductor core inside a shield which is connected to the ground only at one end of the cable. Here, the shield does not conduct current and is, therefore, not part of the signal path... but, still drains EMI/RFI to ground at the connected end.

Note: Have been a reader of this forum for a little while now. Thought it was time to join and add my 2-cents on an issue where there can be many approaches.

[joeinid]

Welcome to the forum, thank you for joining.

[audio.bill]

Welcome to AudioShark alp-tone, nice avatar and first post! Look forward to your continued participation.

[W9TR]

I watched the first video and while it was clear it missed some key things of importance wrt RCA twisted pair interfaces.

Twisted pair cables cancel low frequency interference (hum) that is magnetically induced. Single ended shielded cables do not.

Shielded cables attenuate high frequency and rf interference but allow low frequency magnetic interference through.


RCA cables were never intended for balanced systems. The twisted pair construction will eliminate low frequency power line hum but allow most other EMI and RFI over 100 kHz to pass into the amplifier. What happens then is anyone’s guess, the only thing for sure is it will be capricious and inconsistent.

The best solution is to use balanced XLR cables for balanced systems because they have a shield connected on the sending end of the cable which attenuates the high frequency interference and the twisted pair attenuates the magnetically induced hum component.

If your amplifier has balanced rca inputs it probably has balanced XLR inputs as well, so use the XLR inputs in that case.

[Oly]

Well said, Tom. Very easy to understand without dumbing it down. Thank you.

[Alrainbow]

Thanks for your reply. The post was to spur up conversation and hopefully make others understand why sometimes there Sound is effected.
RCA beyond 10 feet max hurts the highs and allows hum or increase noise floor.
It also stops any iso of ground from one device to the other. Most don't know and worse yet is those who say it's ok.

[W9TR]

Gary,
I’m glad you liked my write up!

Alrainbow,
This is indeed a rich subject that bears more coverage. I’m glad you posted your observations and video. It really does matter how audio designers implement their input and output stages. That’s one of the reasons why our systems can be so cable dependent. There is a lot of interaction between the gear and cables.

I have MIT, Kimber, Audioquest and Mogami RCA cables and they all sound different. There are big differences in these cables - most are shielded, some are unshielded, they all have different geometries and use different materials. Lots of variables. I’m at a loss to fully understand or explain why they sound diffferent. So I just listen and use the one I think sound best.

[Alrainbow]

So glad there is such honesty. It's very complex to answer the why.
Some I can predict by messuting and using formulas if I have know info of ore and amps.
But the kind of transfer used venders don't speak of or list in specs.
I am an advide headphone user too. The right imp of hseodones and amps has a huge effect there. The toughest part is knowing how or should sound in getting a bal sound. As you make one thijg better you move away form another
but knowing some facts of our devices helps