Austrian Litz
MONO AND STEREO HIGH-END AUDIO MAGAZINE
(Continued-from-part-one) …
So !
The last time - I left you off standing in the middle of the room, holding an electric drill in your hand; with a long length of twisted pair wire affixed to the chuck .... wire spanning the whole length of the apartment; the other end of it affixed to a chair at the distant other end .... and generally - looking quite stupid.
But fear not - further instructions follow.
As I mentioned earlier, you need to unify the twist rate between ALL of the twisted pair strands. But how do you check if "such and such" an amount of extra turns, as applied with your drill ... is actually enough ? That is easy. You have a second hand. A free hand. And guess what you are holding in it. You are holding the TEMPLATE stick - the one as prepared earlier - with a visual representation of the "turn rate density". Please put the template against the tensioned wire pair that you have in your drill. At a glance, you will instantly see - if it is "just right", or “not quite” enough, or “too much already” (try to avoid this “too much” scenario at all means!).
m). It is best to not “overdo it” – too much turns and you have a potential problem. So, my advise, do not "over-do" it. Be careful so that you do not have to “regress”, turn back, or loosen up the strands again, as a result of twisting them together too strongly, via switching the drill rotation direction. This is a recipie for trouble. It is possible to accomplish, but special care applies here, as it is now very easy to tangle up the whole thing. No guarantee that it will unwind "evenly". Just try to avoid such a situation in the first place.
When you are “increasing” the turn rate of the pair – you can make occasional (frequent!) stops to monitor your progress. Nobody says that you have to complete the “increasing” of turn rate at a single one “go”. Make pauses. Use the Turn-density-template stick frequently.
n). Eventually, you will end up with a set of three bundles of “turn-density-unified” strands – please make a visual check that they all came out with more or less the same resulting total length. Small variations are obviously a natural phenomenon and are to be anticipated (let's say, differences of 20cm or so). But if the difference is a substantial one, then something is not quite right.
"3 x" Twisted Pair Braid …
"3 x 3 x" Twisted Pair Braid
o). Do you happen to have a black permanent marker ? If affirmative, now is the time to use it. Find the "half length" point of each individual strands and clearly mark it with the marker. Repeat this for each of the three strands. The easiest way to find the “half length point" is simply to attach both ends of the pair to the chair and then stretch the middle to maximum length. The place where it “folds” is obviously the half length point.
p). Roll up TWO large, loose, coils – Each is to hold HALF of the total length of each strand. You need to make the coils from EACH end of the pair, so that the two coils “meet” in the middle, at the “half length” point that you marked with the marker. For best results and ease of braiding,the diameter of the coils should be about 30 to 40 cm. Each coil is to be started from one of the two ends, and rolled up towards the center point, the ‘half-length” point marked on the twisted pair.
q). As you now have three twisted pair lengths and each has a “middle point” marked on it with the marker, so now please align all the middle points in such a manner, so that they meet and are together, next to each other, side by side. The three strands are now center - centered, so to say. Now, remember that outer sheaf that you got rid of ? When you were pealing if off of the cable so as to get to the insides of it and rip out the twisted pairs from it ? Now please take a piece of that outer sheaf and make a small protective sleeve, that you put on and around the “mid-length point” of ALL the three twisted pair strands. Now, holding all three together, in this protection sheaf / outer coating piece, put them in a small vice and secure them, but do not rupture their insulation by squeezing the vice too tightly. It needs to be only a gentle “squeeze”. Just so that they stay there.
You just caught the middle of the length of a strand of the future, yet upbraided speaker cable, or specifically a cable “triplet" ( 3 x 3 ).
And now begins the real ordeal.
y). Start braiding (= American English: "Plaiting" ??) the three twisted pair stands, as if going “from the middle” to one of the ends of the finished triplet.
You ask: But why “working from the middle” and out towards the out-sides ? Is this not twice the amount of hassle, trouble ? Believe me, it is not. It will actually mean LESS work for you. As a result of the “working from the middle outwards” method, you achieve the result that rather than operating with three big rolls of twisted pair wires, comprised of the full-length (16m) of the runs, you will rather do it twice … going from the “middle” – but each and every time working with coils that are half as big (8m), with only a half of the length of the runs of twisted pair wires. Believe me: such “half” rolls are less prone to getting tangled up than the big ones. Keep in mind: your work shall “progress” – as long as you don’t get them tangled up. But once they get tangled up – consider yourself some 10 minutes behind schedule! It simply does not pay to get them tangled up in the first place - even if it means a small little extra amount of care and slightly (seemingly) slower progress.
It is much better to braid the runs from smaller coils / runs of wire. And besides, the last 2 meters of the runs – you do not actually need the coil any more, since a length of 2 meters is “manageable” even if it is loose. It is simply too short to get tangled up any more.
Just for the sake of enabling you to better “visualize” the whole concept: imagine that you are standing half way between your amplifier and your speaker. With the vice in the middle.
Your three stretches of twisted pair wire, that were going to the amp and to the speakers, are coiled up in a total of 6 loops: three from the amplifier side of the vice, and three from the speaker side of the vice. First you braid the 3 coils going in the direction of the amplifier, and then “the other half” – the three going in the direction of the speaker.
Please note that each individual, smallest little twisted pair, consisting of only two tiny (24AWG) wires, is in fact a **Self-Sufficient-Mini**, a very thin **Speaker Cable**. The “Plus” (or the speaker signal from the RED connector of you amplifier) - will be traveling along the colored wire. The “Minus” (or the return speaker signal, going back to the BLACK connector of you amplifier) - will be traveling along the white colored wire.
At the very end of the project, you will have 3 x 3 x 3 = 27 parallel runs of such pairs. And indeed, they will **ALL** be connected in parallel.
You will be using 27 independent sets of tiny speaker cables, all running in a zig-zag and parallel to each other.
This, in essence, constitutes the “innovation” of this speaker cable topology. The speaker cable is constructed as a “two-way” Austrian Litz, just as the Austrians invented it, even prior to World War II, a concept that was successfully used in many a tube radio of times long past, within the high frequency circuits of those old radios. The Austrian Litz wire enabled those coils, back then, to achieve an outstandingly high value of the "Q" (Quality) parameter of the resulting resonant circuits.
Returning back to the V-Cable: in the end, we will have 27 independent miniature speaker cables, all connected in parallel, whereby all the "colored" wires will be joined together, at both ends, so as to constitute the “RED” (or "plus") speaker wire, and the other 27 independent wires, the white ones, will be joined together at both ends, and shall jointly constitute 27 parallel runs of white wires, so as to implement the “BLACK” speaker wire (or the "minus").
The fact that each and every such pair is braided and “interwoven” with other such pair - results in a very favorable characteristic:
The resultant inductance of the final product – our speaker cable, is practically ZERO, up to the seventh decimal position behind the decimal point.
YES. We are talking about Nano - Henries here.
:)
Braiding – not as easy, as one might think.
===================================
The actual activity of braiding, seems straightforward, but none the less – is a bit tricky. It is important:
a). Do not braid too tightly. We do not want the braid to be too stiff. I had a "braid-density-rate" of probably one crossing at every 2cm.
b). Keep each coil of twisted pair “descended”, hanging loosely down, and simply “rearrange”, intertwine the hanging coils, the location of the coils, so as to generate the braid. Coils hanging on short lengths of wire are easier to brade, but require more frequent “unwinding” of the coils (which is always a bit of a hassle and a slow-down). Coils that are hanging on longer lengths of wire require less frequent “unwinding”, ... but are more prone to getting tangled up.
As soon as you use up a length of unwound twisted pair from the coil (as it has “become” a part of the newly braided braid), you need to unwind a consecutive fragment of the coil. For my purposes, in order to keep the coils secure and intact, I used normal washing pegs, clips, the ones that you use to hang out your laundry to dry on a line.
c). From time to time, try “smoothing” the braid, by pulling your clamped hand along the pattern, so as to make it more “elongated”. Do that, let's say, every 30 cm of a newly woven stretch of braid. This activity results in a slimmer braid, with smooth edges, sides. This is important, because we will later be braiding 3 out of 3, and then 3 out of 3 out of 3 (=27). We do not want the final product to look too thick or uneven.
After one half of the triplet is braided, go to the "other side of the vice" and braid the other half of the run ( ... the one going in the direction to the speaker). When working with coils, scrolls of a “half length wire” always result in less problems due to tangling up of the individual coils.
And besides - the "last 2 meters" of the finished up coil - is a non-issue. It is highly unlikely that you will tangle up a stretch of 2 meters or less. So it is always better to start off with shorter lengths of wire in the coils - from the outset.
So, after some mundane braiding activity, you now have completed one run of 1 + 1 + 1 twisted pairs = a “triplet” run ( a “3 x ” twisted pair) …
Repeat the steps as above.
Repeat them two more times.
Once you have three pieces of such individual "triplets" …. you go to the next, higher level of abstraction.
Now you shall braid these three triplets together - braid them into a thicker, compound run, a "3 x 3" (= 9) run.
Repeat ALL the steps above – twice again.
Once you have three pieces of such individual "3 x 3" runs …. yet again, you go to the next, higher level of abstraction.
Now please braid these three runs of "3 x 3" together - into a thicker compound run, a “3 x 3 x 3” ( = 27).
Finished ?
Great !
Now you can take care of your blisters and relax.
Now, UN-BRAID and UN-WIND the individual twisted pairs, at a length of about 20 cm or so, and try to “group” all the white wired together on one side, and all the colored wires on the other side.
If you feel like it, you could braid these ending so as to form nice, neat terminal approach runs. All of the 27 white ones together, and all of the Colored ones – together.
Lets assume that the colored ones represent the positive ("RED") run of your cable.
Join them all together (galvanic - according to your preferred method).
Similarly, lets assume that the "white ones" represent the negative (black) run of your cable.
Again, join all of these together (galvanic).
Repeat all of this from the cable’s “other side”.
Now comes a very important part.
Emotionally cool down. Don't go jumping and connecting the contraption to your amplifier just yet !
Take your multimeter device.
Set it to the “ohms” measurement range.
TEST - that there is no short-circuit between the white wire group and the colored wire group.
It is crucial that there is no “pass” from the colored ones to the white ones.
If this is not the case, the project is a failure.
Trash the whole thing. Do over and start again. A brutal statement - but surely, you do not want to short your amplifier …. and by now - finding the exact spot of where there is a fault in the insulation and where the short circuit is - such a feat is simply not possible to accomplish.
Having said the former, I do hope that you measurements conclude favorably and that no short circuit is detected.
In such a case - apply speaker terminal lugs – according to your preference.
In essence – your cable is ready.
Oh, by the way… Before you put on the terminal lugs, you can pull a nice sleeve on the cable, like the nice nylon ones,
the ones that are sold per meter and are used to mask or group cables. This would be a nice finishing touch.
I made mine in black and they “look” very nice.
A funny observation: the same "nylon sleeve" tends to be much cheaper at an internet auction, or in a car tuning / radio installation store, or an electronics store. Wherever you purchase them - do not purchase them in audio-video stores ... as the price difference will blow your boots off.
Optional:
==========
From the amplifier end, you could apply a ferrite ring on the cable, just prior to mounting your terminal lugs.
A ferrite ring of a highest possible value of ‘magnetic permeability’ – such as those used for filtering noise on the power cables that supply computers or similar.
The purpose of this ring is to prevent any noise/crap (interference), which is everywhere “in the air”, to penetrate into your long antenna (your speaker cable) and via this route, penetrate into the insides of your amplifier. Specifically – into the negative feedback loop of your amplifier, where it heads directly to the most noise sensitive input stages. Believe me, you do not want your favorite FM station’s interference interfering with the preamplifier stage within your amp.
Nervous ? Someone asked me: “.. But this will surely increase my cables inductance and I shall loose the high frequency details ??"
Rest assured and do not worry. Neither about the transient response, nor about your “mids” and “highs” – no harm shall be happening to them.
This ferrite ring is engulfing **BOTH** of the wires, i.e. the one going “out there”, the "plus" - going from the amp to the speaker, but at the same time, it also engulfs the one going “back”, meaning the "return".
Now, the “Net Current Flow” through the inside of this ferrite ring is ZERO. Zero in terms of your music signal at least – as the signal has only one possible return route, it does not split up anywhere, so the "quantity" of the return current is exactly the same as the quantity of the “outbound” current. In each and every moment it will always the same value, but only the directions are opposite. The sum of such two opposites is always zero. Hence, your audio signal “does not see” the presence of this ferrite ring. At all. It is as if it was simply NOT THERE.
OK. So at least we now know that No harm is done.
But … why do we use it at all ?
Well, the ferrite ring acts as a “Common Mode Choke” – It will constitute a barrier, protecting your amplifier and it’s negative feedback loop, from any and all radio interference. But how come ? Well, the radio interference is being applied in the same quantity and according to the same “pattern” to BOTH of your wire runs at the same time – meaning the the one going out to the speaker, as well as the one going back to the amplifier. Look at it this way: your audio signal is a "differential signal", a pair of two opposed currents, one going outbound, and one going in the opposite direction (“inbound”). The net signal is ZERO – at least as far as the ferrite ring is concerned.
But, the radio interference, applied simultaneously to both your cable runs (at the same time and with the same force to the “outbound” and the “return” - simultaneously) – this is a COMMON mode signal, and not a differential mode signal.
But such a common mode signal is blocked by the "common mode choke", as constituted by the ferrite ring.
Your speaker cable is almost ready.
Braiding is complete... Now come the bells and whistles
=============================================
Now, you have to concentrate on the ends of what is to become your elegant speaker cable.
The ends look rather messy at the moment.
We need to do something about it.
On both sides of the cable, we need to trim the endings of the pairs, so that all of them are finished off at the same length.
Please cut / trim the ones that are too long, so as to level them out in length with the shortest pair in the whole lot.
Braiding is complete... Now come the bells and whistles
=============================================
Now, you have to concentrate on the ends of what is to become your elegant speaker cable.
The ends look rather messy at the moment.
We need to do something about it.
On both sides of the cable, we need to trim the endings of the pairs, so that all of them are finished off at the same length.
Please cut / trim the ones that are too long, so as to level them out in length with the shortest pair in the whole lot.
Now, UN-BRAID and UN-WIND the individual twisted pairs, at a length of about 20 cm or so, and try to “group” all the white wired together on one side, and all the colored wires on the other side.
If you feel like it, you could braid these ending so as to form nice, neat terminal approach runs. All of the 27 white ones together, and all of the Colored ones – together.
Lets assume that the colored ones represent the positive ("RED") run of your cable.
Join them all together (galvanic - according to your preferred method).
Similarly, lets assume that the "white ones" represent the negative (black) run of your cable.
Again, join all of these together (galvanic).
Repeat all of this from the cable’s “other side”.
Now comes a very important part.
Emotionally cool down. Don't go jumping and connecting the contraption to your amplifier just yet !
Take your multimeter device.
Set it to the “ohms” measurement range.
TEST - that there is no short-circuit between the white wire group and the colored wire group.
It is crucial that there is no “pass” from the colored ones to the white ones.
If this is not the case, the project is a failure.
Trash the whole thing. Do over and start again. A brutal statement - but surely, you do not want to short your amplifier …. and by now - finding the exact spot of where there is a fault in the insulation and where the short circuit is - such a feat is simply not possible to accomplish.
Having said the former, I do hope that you measurements conclude favorably and that no short circuit is detected.
In such a case - apply speaker terminal lugs – according to your preference.
In essence – your cable is ready.
Oh, by the way… Before you put on the terminal lugs, you can pull a nice sleeve on the cable, like the nice nylon ones,
the ones that are sold per meter and are used to mask or group cables. This would be a nice finishing touch.
I made mine in black and they “look” very nice.
A funny observation: the same "nylon sleeve" tends to be much cheaper at an internet auction, or in a car tuning / radio installation store, or an electronics store. Wherever you purchase them - do not purchase them in audio-video stores ... as the price difference will blow your boots off.
Optional:
==========
From the amplifier end, you could apply a ferrite ring on the cable, just prior to mounting your terminal lugs.
A ferrite ring of a highest possible value of ‘magnetic permeability’ – such as those used for filtering noise on the power cables that supply computers or similar.
The purpose of this ring is to prevent any noise/crap (interference), which is everywhere “in the air”, to penetrate into your long antenna (your speaker cable) and via this route, penetrate into the insides of your amplifier. Specifically – into the negative feedback loop of your amplifier, where it heads directly to the most noise sensitive input stages. Believe me, you do not want your favorite FM station’s interference interfering with the preamplifier stage within your amp.
Nervous ? Someone asked me: “.. But this will surely increase my cables inductance and I shall loose the high frequency details ??"
Rest assured and do not worry. Neither about the transient response, nor about your “mids” and “highs” – no harm shall be happening to them.
This ferrite ring is engulfing **BOTH** of the wires, i.e. the one going “out there”, the "plus" - going from the amp to the speaker, but at the same time, it also engulfs the one going “back”, meaning the "return".
Now, the “Net Current Flow” through the inside of this ferrite ring is ZERO. Zero in terms of your music signal at least – as the signal has only one possible return route, it does not split up anywhere, so the "quantity" of the return current is exactly the same as the quantity of the “outbound” current. In each and every moment it will always the same value, but only the directions are opposite. The sum of such two opposites is always zero. Hence, your audio signal “does not see” the presence of this ferrite ring. At all. It is as if it was simply NOT THERE.
OK. So at least we now know that No harm is done.
But … why do we use it at all ?
Well, the ferrite ring acts as a “Common Mode Choke” – It will constitute a barrier, protecting your amplifier and it’s negative feedback loop, from any and all radio interference. But how come ? Well, the radio interference is being applied in the same quantity and according to the same “pattern” to BOTH of your wire runs at the same time – meaning the the one going out to the speaker, as well as the one going back to the amplifier. Look at it this way: your audio signal is a "differential signal", a pair of two opposed currents, one going outbound, and one going in the opposite direction (“inbound”). The net signal is ZERO – at least as far as the ferrite ring is concerned.
But, the radio interference, applied simultaneously to both your cable runs (at the same time and with the same force to the “outbound” and the “return” - simultaneously) – this is a COMMON mode signal, and not a differential mode signal.
But such a common mode signal is blocked by the "common mode choke", as constituted by the ferrite ring.
Your amplifier is hence protected from radio interference, but at the same time, your music signal is totally unaware of the presence of the ferrite ring. It does not even know that something is there.
So, in short: USE those ferrite rings. They DO NOT harm your signal. But at the same time, they DO provide you with cleaner sounding music, as your preamp is free from radio interference coming from the “output” side, via the Negative Feedback Loop, by which it would have direct access to the most fragile and small signal input circuits of the amplifier.
Once you got those (optional) ferrite rings in place, and you put the speaker terminal lugs on both ends of the cable ... now is the time to start your listening tests.
End of Part II …. To be continued…..
Regards,
http://hiend-audio.com
zjj_wwa@hiend-audio.com
Matej Isak. Mono and Stereo ultra high end audio magazine. All rights reserved. 2006-2013. www.monoandstereo.com. ..:: None of the original text, pictures, that were taken by me, links or my original files can be re-printed or used in any way without prior permission! ::..
So, in short: USE those ferrite rings. They DO NOT harm your signal. But at the same time, they DO provide you with cleaner sounding music, as your preamp is free from radio interference coming from the “output” side, via the Negative Feedback Loop, by which it would have direct access to the most fragile and small signal input circuits of the amplifier.
Once you got those (optional) ferrite rings in place, and you put the speaker terminal lugs on both ends of the cable ... now is the time to start your listening tests.
End of Part II …. To be continued…..
Regards,
http://hiend-audio.com
zjj_wwa@hiend-audio.com
Matej Isak. Mono and Stereo ultra high end audio magazine. All rights reserved. 2006-2013. www.monoandstereo.com. ..:: None of the original text, pictures, that were taken by me, links or my original files can be re-printed or used in any way without prior permission! ::..