[Speedskater]

"RCA interconnects need a co-ax cable."

No they don't.  Quite a few manufacturers are using balanced microphone type cable for RCA interconnects.  One center conductor goes to hot and the other is ground on each end of the cable.  The shield is hooked up to the ground on the source end of the cable and not connected at the receiving end.  This works.  The 2 conductors are identical and there seems to be less common mode noise between components.  Many brands of directional RCA cables are hooked up in this manner.
neo

I'll stay with the writings of experts like:

Henry W. Ott
Bruno Putzeys
Jim Brown
Bill Whitlock

[WireNut]

Well Belden makes a long list of two conductor shielded cables and often mechanical features govern the final choice.

Model numbers like 1800F, 8412, 8413, 2221, come to mind.  First choice is probably the 1800F.

1800F looks like a well made cable. Conductors are smaller 24awg instead of 20awg used in 89207, insulation is Polyethylene/PVC rather than Teflon. Both would make good DIY interconnects competing with the big high dollar boys.

1800F will be more flexible then 89207. The 89207 uses 2 Teflon insulated conductors that are wrapped inside of another Teflon tube followed by a foil and copper braid shield with a Teflon outer Jacket.
It’s a stiff cable.

[john dozier]

The Gore cable I cited is not as stiff as the Belden, but still not as flexible as normal mic cable. There is only one distributor for this cable (it is rather esoteric) and I am checking with them to see if small quantities can be obtained. I obtained a sample thru a company that I own. Regards

[john dozier]

Bill Whitlock especially. Did you know that ClassD Audio amps use an input circuit he designed? Balanced of course. Regards

[DaveC113]

The design of my cables had certainly been influenced by material Bill Whitlock has written.

I do disagree that a single ended IC needs to be coax though. From lots of experimentation, I have found they don't sound as good as unshielded ICs, and you can also infer through Bill's presentations as well as explanations by jneutron here on AC that the shielding from coax cables doesn't work the way it was designed to when used for single ended audio ICs.

[Folsom]

I'm a fan of the Blue Jeans. They're better than home-made things I've tried like Belden 89259.

While their capacitance is impressive, not having the ground and signal twisted may let a mild amount of phase shift occur at the peaks (haven't seen documentation in the audio signal, but this occurs with AC). I'm not going to say I claim coaxial is superior for that reason, but in the cheap n cheerful range I can't recommend anything else. I'm very pleased with them for every cable I have (RCA).

[Wayner]

Here is a theory for all of you to ponder. Would you run a 20 amp circuit on delicate wires of an MC phono cartridge? Of course, the answer is no. On the contrary then, why would you run a smallish signal like .25mv on a relatively large conductor? A .25mv signal from a phono cartridge run thru a meter's length of even 25 awg wire is the counter revolutionary to ampacity of heavy current. There simply is not enough drive current to effectively get the signal thru the wires.

We all have been trained that we need heavy cables for power. Perhaps it's true for speakers (I find the heavier gauge beneficial, but the number of strands even more important), but from the signal end, if works the other way. The smaller the gauge the better, and IMO, the center pin conductor must be a single strand. Could you imagine running an MC cartridge thru pure copper cable that is 0000 size? There isn't enough drive current to even excite many of the copper atoms. That is where there is system synergy failure. Wire gauge must be held to strict sizes for the currents being carried. Small signal, small wire, large signal, large wire. Small power, small wire, large power, large wire...

Get it?

It's the system's synergy and just one failure at one point destroys the system. Forget about the geometry for awhile and concentrate on the wire gauge for the task.

Wayner

[neobop]

Here is a theory for all of you to ponder. Would you run a 20 amp circuit on delicate wires of an MC phono cartridge? Of course, the answer is no. On the contrary then, why would you run a smallish signal like .25mv on a relatively large conductor? A .25mv signal from a phono cartridge run thru a meter's length of even 25 awg wire is the counter revolutionary to ampacity of heavy current. There simply is not enough drive current to effectively get the signal thru the wires.

We all have been trained that we need heavy cables for power. Perhaps it's true for speakers (I find the heavier gauge beneficial, but the number of strands even more important), but from the signal end, if works the other way. The smaller the gauge the better, and IMO, the center pin conductor must be a single strand. Could you imagine running an MC cartridge thru pure copper cable that is 0000 size? There isn't enough drive current to even excite many of the copper atoms. That is where there is system synergy failure. Wire gauge must be held to strict sizes for the currents being carried. Small signal, small wire, large signal, large wire. Small power, small wire, large power, large wire...

Get it?

It's the system's synergy and just one failure at one point destroys the system. Forget about the geometry for awhile and concentrate on the wire gauge for the task.

Wayner

Wouldn't a single strand have greater resistance and defeat the purpose?
Internal tonearm wire is pretty thin the way it is.  A LOMC has relatively high current, as opposed to a HO cart that has greater voltage and low current.
Seems to work okay the way it is.
neo

[Folsom]

Wayner you might be onto something for signal, but not AC power within reasonable means.

The AC power, the more freely on demand it flows, the easier the circuit can quickly and accurately drive signal. Once you hit that shift the integrity of the signal is equally as important to the ability to drive it well.

Once you make a conductor small enough to a point, it could be subject to non-skin-effect. From what I've read you can get a flatter response from going small (to a point), in reasonable terms. You can get a similar flat response by increases the size, but the size might be excessive (3 AWG, maybe bigger). But that's only a discussion on attenuation. Then you have capacitance as a factor. Lastly how much noise shielding do you need (and how much does it help if your equipment isn't star-grounded?) vs. phase congruency (increased by different twisting methods primarily). Larger is smaller resistance, but in this case given impedances between equipment I doubt it is your biggest concern.

I'd be more worried about equipment from one to another driving. Need a buffer, new volume control, etc? But that's after AC power conditioning for me anyway.

I think it's reasonable to say some interconnects "benefits" are gimmicks. You can only get so small and so pure on conductors, etc.

[Russell Dawkins]

We all have been trained that we need heavy cables for power. Perhaps it's true for speakers (I find the heavier gauge beneficial, but the number of strands even more important), but from the signal end, if works the other way. The smaller the gauge the better, and IMO, the center pin conductor must be a single strand. Could you imagine running an MC cartridge thru pure copper cable that is 0000 size? There isn't enough drive current to even excite many of the copper atoms. That is where there is system synergy failure. Wire gauge must be held to strict sizes for the currents being carried. Small signal, small wire, large signal, large wire. Small power, small wire, large power, large wire...


Wayner

I don't know if you are aware of Denis Morecroft's work, but he is one of the leading proponents of this type of approach (minimalist single strand conductors and attention paid to eddy current effect - and much more):
http://www.dnm.co.uk/principles.html
here's his preamp:
http://www.stereophile.com/artdudleylistening/308listen/index.html
...and here's an interview from 2004:
http://www.stereophile.com/interviews/404listening/index.html

[WireNut]

 To me it seems like the hardest thing to decide on are the connectors. If you only need 4, it’s not such a big deal. If you want to do your whole system and need 20 the decision gets a bit tougher.

 If you needed 20 decent RCA connectors, which one/s would you buy. Let’s say your budget is $200.00 for all 20 RCA’s.

[DaveC113]

To me it seems like the hardest thing to decide on are the connectors. If you only need 4, it’s not such a big deal. If you want to do your whole system and need 20 the decision gets a bit tougher.

 If you needed 20 decent RCA connectors, which one/s would you buy. Let’s say your budget is $200.00 for all 20 RCA’s.

You can find Furutech FP-126 RCAs on sale for close to that price. They have UPOCC copper center pins and are very robust, well constructed connectors. Connectors make a really big difference in how an IC sounds.



As for the small diameter signal wire, if you go too small it will throw the balance off and it will sound "thin". The best conductors for audio maximize surface area to minimize skin effect. Litz type wire was designed to eliminate skin effect at RF freqs and it works great for audio too. My ICs have ~166 strands of individually insulated 44 gauge UPOCC copper wires for the signal wire, 14g speaker cables use ~1060 strands. A thin rectangle or foil type conductor tends to work well too, like the Duelund silver hook up wire. A single strand of round wire can sound ok but it'll never be as good as multiple runs of smaller diameter individually insulated wires. For ground wire on ICs it is more important to minimize resistance.

[srb]

If you needed 20 decent RCA connectors, which one/s would you buy. Let’s say your budget is $200.00 for all 20 RCA’s.

I prefer locking RCA connectors.  It's not that I'm worried about them coming unplugged, it's because many RCA plugs are too tight fitting and can stress RCA jacks (and the PCB) if they are not panel mounted with a retaining nut.  The locking types plug in easily and are then tightened for a tight secure ground connection.

Furez FZ091LRG Locking RCA Plug - $12.50/pair

[Sonny]

I prefer locking RCA connectors.  It's not that I'm worried about them coming unplugged, it's because many RCA plugs are too tight fitting and can stress RCA jacks (and the PCB) if they are not panel mounted with a retaining nut.  The locking types plug in easily and are then tightened for a tight secure ground connection.

Furez FZ091LRG Locking RCA Plug - $12.50/pair

These do look pretty nice and Furutech makes some very expensive stuff!  Only thing is, I try to stay away from overly large conductors that will ultimately be in the way of the tip of the cable and the RCA input jacks.  I believe it's always best to have as little as possible between two tips of the connections, therefore reducing the "displacement" of the signal transfer...but maybe I am just talking out of my arse....

T

[Wayner]

I don't know if you are aware of Denis Morecroft's work, but he is one of the leading proponents of this type of approach (minimalist single strand conductors and attention paid to eddy current effect - and much more):
http://www.dnm.co.uk/principles.html
here's his preamp:
http://www.stereophile.com/artdudleylistening/308listen/index.html
...and here's an interview from 2004:
http://www.stereophile.com/interviews/404listening/index.html

Thanks for the links, Russell.

Wayner