[andyr]

I have in my hand a Multicap RTX 1uF cap - typically used as a coupling capacitor - and I see that its leads register about 1.2mm diameter on my micrometer.

This puzzles me as, supposedly, 1.2mm is waaay thicker than the "recomended" diameter for use in signal hookup wire or ICs.

It seems to me there's a conundrum here?  What's the point of choosing ICs which use thin (maybe only 30awg) wires if the signal then passes through the 1.2mm leads on the coupling cap?  Surely this must degrade the signal?

Can anybody throw light on this?

Regards,

Andy

[speedcenter]

A lot of the caps that have those thick leads are used in power supply appications as well, and then the leads need to be a little bigger than 30awg or whatever is fine for coupling a line level signal.

On Auricaps, I usually cut them as short as I dare, then solder the fine wires I use for signals to the stubby wiring left on the caps and secure everything with some heat shrink

Peter

[jdybnis]

Well the RTX line is rated at 400-600v. It's is designed to go into crossovers and power amps too. So big leads make more sense.

BTW if you are using Multicap RTX caps the long break time in is not optional. It takes 150+ hours before they sound as good as the cheaper polypropylene caps in the Multicap line. 300+ hours before they sound excellent. And straight out of the box they sound awful.

[peranders]

Thick leads are chosen not for fun. I'll suspect that this has to do with the weight of the cap. Mechanical reasons more than electrical.

[andyr]

Thick leads are chosen not for fun. I'll suspect that this has to do with the weight of the cap. Mechanical reasons more than electrical.

Hi, peranders,

I have no doubt you are correct but this seems to me to be a problem!  One is advised to use hookup & IC wire which is thin enough to avoid "skin effect" or whatever other "effect" causes smearing, bass bloat etc. etc. yet the (high quality) coupling caps have leads which are way thicker!!

I guess my thinking was that if the coupling cap leads are so thick, what's the point in using thinner wire elsewhere ... the signal is already "stuffed"!!??

Regards,

Andy

[peranders]

Interesting, you mean thin wires have less skin effect? Can you develop this claim a bit. If you don't use Litz wire, a single wire has more skin effect  than a thick. It's also good to know how big this skin effect is compared to the inductance and audio frequences. If you do some calculations you may come to the conclusion that a 1.2 mm wire has it's advantages after all.

[andyr]

Interesting, you mean thin wires have less skin effect? Can you develop this claim a bit. If you don't use Litz wire, a single wire has more skin effect  than a thick. It's also good to know how big this skin effect is compared to the inductance and audio frequences. If you do some calculations you may come to the conclusion that a 1.2 mm wire has it's advantages after all.

Yes, I am talking about using several, insulated thin wires ... I believe this is called Litz wire?  (I do not use stranded wire anywhere in my system.)

I do not have the background to be able to do the appropriate calculations but I have read that many people espouse the concept that a single thick wire does more damage to the signal than a collection of thinner, insulated wires totalling the same guage.  I have never ever read that a 1.2mm wire will be better than the equivalent number of insulated thinner wires.

Hence my Q.

Regards,

Andy

[peranders]

I'm not going to convince you how big or small the skin effect is when it comes to audio. I only want to give some numbers.

At  10 kHz the skin depth 0.66 mm => 1.2 mm wire is enough ... but how much does this influence in the circuit? One inch copper, 1.2 mm = 488 microohms

If you add this loss 488 uOhms to the input impedance of some of your circuits, let's say 10 kohms.... and if you change the wire to a Litz wire with resistance of 487 uOhms, how much difference do you get really?

As you may notice I'm not very convince about the inportance of the skin effect if it's about microohms and you have milliohms in every contact.

So as a conclusion, a 1.2 mm wire is not worse than a thinner one but many thin insulated wires are better than one thick..... but at which frequences?

You can read more here:
http://en.wikipedia.org/wiki/Skin_effect

So to go back to your question: If it's only about one single wire it is better with thicker wire up to a certain limit when it doesn't matter if it's only about electrical condunctivity. I other words: You can feel safe.

[Christopher Witmer]

"At radio frequencies, Litz wire is often used to eliminate the skin effect.  This occurs because of the tendency for RF to try to escape from the wire, so it concentrates on the outside (or skin) of the wire.  The effect actually occurs as soon as the frequency is above DC, but becomes noticeable only at higher frequencies.  Litz wire will not affect your hi-fi, unless you can hear signals above 100kHz or so (assuming of course that you can find music with harmonics that go that high, and a recording medium that will deliver them to you).  Even then, the difference will be minimal."

So says Rod Elliott in his online paper "Cables, Interconnects & Other Stuff - Part 3" (http://sound.westhost.com/cables-p3.htm).

As far as theory goes, what Rod says above would seem to be unassailable. His opening sentence, "All well designed interconnects will sound the same," also follows logically. At the same time, it remains a fact that people can and do hear differences among cables where, theoretically, no difference should be heard.

I have purchased a large spool of Litz wire for experimenting with "one of these days" and I figure "Litz wire can't hurt" (at least in theory!)

On the other hand, one of my best friends uses piano string wire for his interconnects and speaker cables. You know, the copper wire that is wrapped around steel wire to create the bass strings for pianos? He buys that copper wire by the spool and builds his own cables. Just a single strand of heavy wire. He won't use anything else. He'll try anything, but he always goes back to that particular type of heavy wire.

[peranders]

You choose materials because you like them. You don't have to give any motivation for your choices really, so if you like Litz wire, use it.

[andyr]

[quote="Christopher Witmer...  On the other hand, one of my best friends uses piano string wire for his interconnects and speaker cables. You know, the copper wire that is wrapped around steel wire to create the bass strings for pianos? He buys that copper wire by the spool and builds his own cables. Just a single strand of heavy wire. He won't use anything else. He'll try anything, but he always goes back to that particular type of heavy wire....[/quote] Hi, Christopher,

I haven't looked closely at the innards of a grand piano recently but I wouldn't have thought the copper wire which is wrapped around the steel core-wire on bass strings is actually "thick"?

Do you happen to know its guage ... I would guess it might be 20awg, at the most (ie. 0.8mm diam)??  If I am correct then using what is, in effect, 20awg "magnet wire" is not particularly unusual for ICs ... and is an approach I thoroughly approve of!

Regards,

Andy

[avahifi]

After putting in over 100 hours designing a new audio circuit board and doing the engineering math and measurements to get something really really right, I am just amazed to see this nonsense discussion of capacitor leads.

Guys, about 90 percent of the component connections and paths in your equipment are on the circuit boards, made of good old flow solder coated copper foil paths.  How I hate having to go up against magic and witchcraft from those knowing ziltch about electrical engineering.

Do you want to check those capacitors and see if they are inductive wound or microphonic or heat sensitive?  Of course not, its the thickness and material of the leads that is important.  Utter claptrap.

Frank Van Alstine

[_scotty_]

Frank I have to agree with you on this subject. Of course one has to remember that one of the prerequisites of being an audiophile is the ability
to strain gnats while swallowing camels.  
Scotty