"The HELIX IMAGE" - With a little help from my friends

This post details the very latest developments and updates to the Helix Geometry.
The developments are courtesy of Ernst of Austria and Yordan & Evgeny of Bulgaria

Yordan and Evgeny have contributed with...
  • the performance aspects of various wire types and metallurgy,
  • discovered that the direction the helix coil was wound is critical - see Inside The Helix Geometry.
  • provided an adapted geometry, based on Ernst’s findings, for the HELIX IMAGE Mundorf XLR Interconnect - see ** The HELIX IMAGE Interconenct (1)

Ernst embraced the Helix design some time ago and has been experimenting with some different materials in order to improve on the performance of the Helix design with astounding success.

His first development was to eliminate the use of as many man-made insulation products (e.g. teflon tubing, expandable Nylon sleeve) used in the original designs.
His second development was to use balsa wood as the spacers every few centimetres in order to hold the signal wire in his speaker cables in the centre of the Helix coil.

The reward for Ernst’s endeavours was a significant improvement is sound quality with respect to improved details, clarity, dynamics, bass control and depth and a significantly wider and deeper image.

His approach considered the Dielectric Constant (D.C.) of various materials.
  • Dielectric constant, property of electrical insulating material (a dielectric) equal to the ratio of the capacitance of a capacitor filled with the given material to the capacitance of an identical capacitor in a vacuum without the dielectric material.

Ernst found that using materials having a lower D.C. than that of the insulation, expandable Nylon and heat shrink originally used to centre the signal wire in the Helix, significantly improves on the performance of the cable.
  • Since air has a D.C. = 1.1, placing the spacers at intervals on the signal wire improved signal transfer even further.
After giving his findings lots of consideration and thought, and after significant experimentation of my own, I now use insulation materials that have a significantly lower D.C. than the Teflon insulation I had used on earlier versions of the cables, which has improved the clarity, details and imaging capabilities of the Helix Cables to levels I had nor observed to this point.

My “adaptions” of findings from Yordan, Evgeny and Ernst, can be found in the following construction details...
The latest design of the Interconnect Cable...

The latest design of the Speaker Cable...

The latest design of the Power Cable...

I am currently using cables that have been modified as in the links above and can report that the modifications have resulted in significant and easily discernible audible improvements over the older design. Improved clarity, sense of space, dynamic performance and improved details are the benefits observed by the changes in insulation.

I have listed a few options of wires that can be used for the signal and neutral wires, but the digram below shows which wires I use and for which components


System Cables

The original helix design concept was to eliminate the parallel conductors commonly used in conventional cable architectures in order to minimizes the noise, proximity effect and Skin effect to imperceivable levels, improving clarity and dynamic performance of the interconnect.

Since those early days, developments include the selection of advanced wire metallurgy, gauge of wire best suited to the task at hand and types of insulation in order to reduce noise to a minimum, which brings us to this moment in time.

The instructions on this web site demonstrates how these cables can be fabricated in the easiest and most cost effective manner in order to achieve extremely high levels of resolution that competes with the very best commercially available products for a fraction of the cost.

Will there be any further updates - probably, because there is always someone, like Ernst, Jordan and Evgeny that is looking to improve on the capabilities of “The Helix” cable geometry.

I normally indicate change by issuing an updated MK # (Mk I Mk II etc...), but in this case I have decided to reflect the latest updates by renaming this line of cables
“The HELIX IMAGE” simply because these cables now convey the most realistic and compelling image I have ever observed in any system

The level of detail and clarity, together with precise location of performers and an image that envelopes the listener is stunning

I would like to thank and congratulate Ernst, Yordan and Evgeny on these exciting new developments.

The stunning performance of Helix Cables of today are due to their efforts


Earlier contributors include Todd (US) for developing the first bi-wire version of the Helix speaker cables, Ghislain (Canada), John (USA) and many others

If you have any further questions on these upgrades just drop me a line.

Regards - Steve

Its More Than Just Numbers - Isn't It?

This post addresses the electrical measurements of the three Helix Cables - Interconnect, Speaker and Power cables.

Having said that, the table below is simply a “guide”, since the values depicted are specific to the cables measured.

Minor differences can be expected due to variations in winding the helix, cable length, wire used and sleeving used.
e.g, one person has measured the capacitance of a 0.75 meter interconnect to be around 34 pF

The cables YOU build may not have identical numbers, but they will be fairly close, provided you use similar techniques, parts and wires.

Also - the numbers below are for cables of a specific length. So you will have to estimate the numbers for your cables if their length differs from those below.

Interconnect Cables - 3 ft long - using the 1mm dia Mundorf Solid Silver/Gold wire with the cotton sleeve insulation

  • Capacitance = 38 pF
  • Inductance = 1.3 uH

Speaker Cables - 10 ft long - using the Duelund 16 gauge tinned copper with cotton/oil insulation

  • Capacitance = 95 pF
  • Inductance = 3.8 uH

Power Cables - 4 ft long - using the Duelund 12 gauge tinned copper with the Polymer Insulation

  • Capacitance = 145 pF
  • Inductance = 1.0 uH


So if you cables are different length you could estimate their related values as follows...

e.g. if YOUR speakers cables are 7 ft long then the numbers can be
“estimated” as follows...

Capacitance: 95 / 10 x 7 = 66.5 pf
Inductance: 3.2 / 10 x 7 = 2.24 uH

Notes:
Loop Inductance -
was measured across the cable at one end, while shorting cable at the other end,
Capacitance was measured across the two conductors with the other end of the cable left “open”
Measurements were taken using an L C meter.

If you really want to get into the science take a look at this link...
http://www.epanorama.net/documents/wiring/cable_impedance.html


So - what do all those numbers (metrics) actually mean?

Rather than delve into complex formulas, I thought that comparing the Helix numbers to other well known commercial brands of cables might be easier for readers to understand, e.g...
  • The 95 pF capacitance (roughly 30 pF/Meter) of the Helix Speaker Cable is significantly lower than some cables from Kimber Kable and TOTL Cardas cables which often exceed 300pF/Meter. This is important if connecting to a high current solid state design amplifier.
  • The 3.8 uH inductance (roughly 1.3 uH/Meter) of the Helix Speaker Cable is higher than some other brands, but NAIM NAC A5 cable is rated at 1.0 uH/meter (highly recommended by NAIM). I have owned a NAIM amp and the Helix cables worked very well with it and also with some other brands that adopt a high current design philosophy
  • One of the few companies that seem to have been able to keep both Capacitance and Inductance to very low levels is Nordost - however, a fellow DIYer’s that tried the Helix promptly sold off their Nordost cables in favour of the Helix - go figure Happy

I consider the Capacitance and Inductance values above to be in the low to medium range when compared to many cables I have looked at from some well established brands

Based on feedback from others who have tried them, they appear be a very good match to a lot of audio components. (see “IMPORTANT:” below) and will minimize many of the issues that conventional cable geometries suffer from.

The Loop Inductance of the Helix Speaker Cable,
may be higher than other cables out there, and some people may believe this to be an issue in the upper end of the “generally accepted audio spectrum” of 20Hz and 20kHz.

However, I believe that this does not present any problems, when you consider the frequency range of a person’s “normal” hearing abilities lies between
20Hz and 12kHz over the age of 50.

Of course - if you are a teenager with excellent hearing you may be able to hear as high as 17kHz, (and perhaps a little higher) at which point you may observe a very small decrease in volume in the
15kHz-20Khz range

If you are an engineer in one of the many companies out there that promotes frequency response of their components to be 0Hz to 100kHz - then you may not consider these cables a viable option.


I have posted the Helix numbers above - because I have been asked for them many times, however...

Cable metrics should be used ONLY as a guide!

They ARE NOT a substitute for actually - LISTENING!


IMPORTANT:- electrostatic speakers is an area I have NO experience of, so I would strongly recommend anyone looking at using the Helix Speaker Cables with electrostatic speakers to look at the statistics above and assessing their possible impact before building or connecting Helix Speaker Cables


HELIX Q & A

Over the years I have often been asked these few questions below.

Why a Helix Geometry?
  • I had believed for sometime that with a conventional geometry, where the conductors were positioned side by side, there could be noise generate within the cable due to the process of induction between the wires.
  • There is also proximity effect and skin effect which can degrade signal transmission
  • In order to minimize these effects you need to eliminate side-by-side conductors
  • With the Helix Geometry - the neutral wire crosses the signal wire at almost 90 degrees
  • No more induction, skin effect or proximity effect - but you now have a much longer neutral wire
  • To offset the effect of additional resistance in the neutral wire - use a wire of a larger diameter
  • But that can sometime make a cable too thick - in which case I use a double run of wire for the neutral

What does it mean in audible terms? - with less noise being generated within the cable itself, the Helix cables sound more open, with faster dynamics, more details and improved clarity, together with an outstanding image. You also reduce the "filtering effect" resulting in a more neutral sound

How important are Materials?

THE WIRE:
  • When building cables most DIYer's focus on the quality of the conductor (or wire)
  • e.g. they will opt for OFC Copper, OCC Copper, Silver Coated Copper, or Silver
  • So what's the difference? - They each conduct electricity at differing rates
  • the International Annealed Copper Standard (IACS) was established to standardize the quality of copper used for electrical purposes
  • annealed copper is the benchmark standard - rated at 100%
  • Silver, by comparison, has an IACS rating of 107%
  • the rest are somewhere in between

What does it mean in audible terms? - the sound of cables made using a better quality wire will improve dynamics and details.

THE INSULATION:
  • Even though the metallurgy of a cable will contribute significantly to the performance of the end product, recent collaborations with other DIYers focussed on the type of Insulation used on the wire.
  • Each insulation type has a different Dielectric Constant or D.C. - Teflon has a D.C. of 2.1 and PVC has a D.C. of 3.18
  • For interconnect cables and speaker cables, cotton has proven to be an exceptional insulation with a D.C. around 1.3
  • For power cables the insulation has to withstand much higher voltages, therefore cotton is not a good choice.
  • You should select wire with a mains rated insulation that can withstand voltage up to 600 volts
  • Duelund has mains rated wire with their proprietary Polymer insulation, which is better than Teflon
  • The best insulation for power cables I have found to date is an insulation called AirLok which has a D.C. just less than 1.45
  • VH Audio is one vendor that sells wire with AirLok insulation that is specifically rated for mains use i.e. 600 volts.
  • BUT be aware that not all wires with AirLok Insulation is rated for mains use - so look for the 600 volts rating

What does this mean in audible terms? - lowering the D.C. of the insulation used will improve clarity and detail and with that, a more precise and expansive image.


Which Helix cable should I make first?
  • I normally recommend making the speaker cables first, because they are the easiest to fabricate and they provide the most noticeable improvement in sound quality
  • Next I would recommend the Interconnect cable, because it eliminates noise on the neutral side of the attached components, which improves clarity and imaging
  • Power cables should be the last to be built, because without the Interconnect or Speaker cables the full impact of the Helix geometry power cable cannot be completely observed

Power Cables:

What gauge wire should I use for the various components ?
  • I have found that for Amplifiers a 12 gauge Live conductor with dual 12 gauge neutral and ground conductors works the best
  • For source components I have found that an 18 gauge solid silver conductor provides significant benefit, with dual 14 gauge neutral wires
Do I have to solder the spades to the wires?
  • I have found that crimping + soldering provides the best results,
  • Crimping Only, works almost as well, so omitting the solder will not cause a significant impact to sound quality
  • Bare wires do not perform as well as spades and it is highly probable that the clamping device in the plug/connector will work loose over time.
  • Not only are spades an important safety consideration, they do actually improve performance

Interconnect cables:

Can a Helix Interconnect Cable be used as a SPDIF (digital) interconnect?
  • Absolutely - they are excellent for digital transfers and the KLE Innovations RCA’s ensure they are completely compatible with 50, 75 and 100 ohm digital interfaces
  • Internal reflections, a common problem in other SPDIF cables are mitigated by using the KLE Innovations RCA plugs
  • Based on my own observations, the KLE Innovations Silver Harmony provides adequate capabilities to handle all digital transfers up to 24 bit 192kHz
  • If you require larger/faster transfer rates I would recommend upgrading the RCA to the Pure Harmony or Absolute Harmony model
  • You can also use cables shorter than 1.5 meters for digital transfers - I have used Helix cables as short as 45 cm without any noticeable degradation in signal transfers.
  • A minimum length of 1.5 meters is often cited as providing the best performance for other cable geometries.



All Cables:

Do I need to ad a wire “mesh” screen to interconnects? e.g. similar to COAX cables
  • No - the helix neutral & ground conductors act as a very effective screen
  • It also acts as a Faraday Cage and protects the signal/live wire from external RFI/EMI

Do I have to use the components (plugs, wire etc..) listed on the site ?
  • Absolutely not, you are free to use whichever materials you feel are best suited to your budget.
  • However, all materials listed on the site are those I have found to provide exceptional sound quality.
  • Unfortunately I cannot provide an opinion as to the performance or materials you may wish to select, my apologies.

How does the Helix geometry compare to other “cable geometries”, such as the ribbon style geometry
  • The helix geometry is superior to other geometries in that they prevent noise form entering all connected components via the conductors
  • The Helix geometry can be used to build Speaker, Interconnect and Power Cables. Other geometries may not “scale” so well to power cables in particular
  • The helix windings serve as a very effective screen to deter noise pollution from external RFI/EMI sources entering your system

Can I use Helix cables on any audio/video equipment ?
  • To my knowledge helix cables offer significant improvements to sound quality on both Tube and Solid State equipment
  • Power cables tend to offer a more noticeable improvement on those components the have a less robust power supply
  • When used on large mono block amplifiers the improvements in sound quality tend to be more subtle in nature, but still noticeable.

They look very complicated to build - are they?
  • Perhaps the first cable you build will present some challenges during construction.
  • But once you get the hang of winding the helix coil with the aid of a rod and drill then subsequent sets of cables will be much easier to fabricate
  • I recommend winding a “test coil”, using a piece of household wire to start with.

Will using multiple conductors for the live (or signal) conductors make a difference?
  • It will change the capacitance and inductance of the cable somewhat, but without trying it it is hard to “guesstimate” the impact
  • This may not be too much of an issue for the components you are using, but you should be aware these changes do exist.

Does the direction of the winding of the helix coil make any difference?
  • IT DOES - PLEASE READ : Inside The Helix Geometry.
  • It will not harm your components if the Helix Coil is wound in the other direction
  • it just sounds better when the helix coil is wound in the correct direction.


AND - IF YOU HAVE ANY OTHER QUESTIONS - JUST ASK

Cone Feet - Isolation or Draining?

What is the Purpose of Component Feet?

When I first looked at component feet, most of them were made from a rubberized material, which would suggest that their prime function was to prevent vibrations from being transferred to the component.

I quickly learned that those rubber feet were less than ideal at satisfying that particular goal, so I looked into Cone feet.

Having considerably less surface area in contact with the shelf of the component rack seemed like a logical step, but I was not sure of the effectiveness of the various cones and spikes and thought they might actually anchor” the component to the shelf.

After applying some thought to the problem I came up with a DIY “ball bearing” and “marble” feet (see below), which seemed to work very well and did not require the little spike protectors to prevent the foot from digging into the shelf.

I also applied a small piece of sorbothane between the component and the DIY foot to further isolate the component from rack-born vibrations.


DSC_8728_00001_01

More recently, I decided to investigate cone feet in more depth after an interesting exchange with the fellow DIY audio enthusiast,

For more information take a look at:
http://www.symposiumusa.com/tech1.html

Turns out, my thoughts about isolating the component from the rack were only partially correct.

A much more interesting aspect of applying cone feet to a component, is their ability to drain vibrations from he component case/chassis, which improves clarity and imaging.

So I decided to try some beech wood cones just to see what effect they might have, and was quite surprised at the improvement in sound quality


The DIY enthusiast informed me that Brass cones provided the best sound, so I decided to try some different materials in order to assess, which material would provide the best improvements.

I decided I would limit this exercise to the materials in the above picture, wood, brass, steel ball-bearing on steel washer and glass-marble on steel washer, which were placed under the Phono stage, since in previous auditions the phono stage appeared to be quite sensitive to the style of foot..

The first audition was the Ball-bearing on steel washer - without the layer of sorbothane
  • this combination sounded very clear, but unfortunately the image had been moved very far back behind the speakers.
  • imaging was very focussed but overall the image was very narrow
  • it also resulted in a loss of volume
  • it sounded similar to being at a hockey game in the seats furthest away from the ice
  • however, the dynamics were very fast, to the point of sounding quite brittle

The second audition was the Glass Marble on Steel Washer
  • This was much better than the Ball-Bearing in that it brought the image back to a more disirable location behind the speakers
  • Clarity sounded a little less harsh than the ball-bearing
  • image size was larger and very well focussed
  • Dynamics were crisp, without appearing brittle

The third audition was with 1.25” Beech wood cones
  • This was the warmest of all the materials with mid tones being a touch more prominent
  • The image was larger than either of the DIY feet but a little less focussed.
  • The dynamics were not quite as crisp as they were with the DIY feet, but just by a very small margin

The final audition utilized brass feet that I had made for me.
  • The brass feet performed very close to the Beech Wood feet
  • They provided the widest image and improved on musician placement and focus
  • Dynamics improved to match the DIY feet
  • They were not quite as warm as the Beech Wood feet, but sounded very full

Other factors that will effect the sound quality ...

The size of the foot used for a given component
  • On my Bluesound Node 2 there is very little space within which to place the feet, so I use 3/4” diameter cones.
  • The Phono stage was a little larger, so I am using 1.25” diameter cones and larger cones made no difference
  • My amp seemed to sound the best with 2” diameter cones
  • The Turntable has 2.5” diameter cones, but that is more for overall styling than effectiveness

Foot placement
  • This is unique for each component
  • For my amp the two main feet are placed each side of the mains transformer and the third foot positioned for optimal stability
  • For my phono stage the best results were obtained be placing one under the transformer one under the circuit board and the third for optimal stability
  • For the Bluesound Node 2 there was not much room, so I placed 2 at the rear and one at the front
  • The turntable was perhaps the most complex (see diagram below)


The Node 2

DSC_0024



The Phono Stage

DSC_0027




The Turntable

DSC_0020

Foot Location is as follows...
  • As close to the edge of the turntable as possible
  • Equal distance from the three centre lines created by the
  • FOOT 1 to spindle to arm bearing
  • spindle to FOOT 2
  • spindle to fFOOT 3

TT Feet

PLEASE NOTE: This is far from a definitive analysis of Cone performance and placement, but it did yield a substantial improvement in clarity, imaging and focus.

I would recommend you try both wood feet and brass feet to see which works best for your individual components and try different foot positions - it will surprise you.

I hope this inspires you to try them for yourself.

DIY BRASS CONE DIMENSIONS
  • The angle of the cone section was 10 degrees from the horizontal plane
  • the height of the shoulder on the cones were
  • 3/4” diameter cone had a 3/16” shoulder
  • 1 1/4” diameter cone had a 1/2” shoulder
  • 2” diameter cone had a 3/4” shoulder
  • 3/4” diameter cone had a 1”” shoulder

The cost of making 5 sets of three feet was $300 CDN

The cones were made at a small local fabrication company and the brass was purchased from Metal Supermarkets

My Rack is made from steel, from a company called Lovan and is there entry level product
http://www.lovanaudiogroup.com/basic-line.html

Each shelf is MDF and has a granite tile on top with a layer of drawer liner between them

The cones sit directly on the granite - I do not use the little brass protector feet often sold for speakers


page6_blog_entry61-page6_blog_entry60-page6_blog_entry52-page6_blog_entry40-two-thumbs-up-2 A highly recommended project!

Inside The Helix Geometry.

Since its conception, I have been sharing ideas and thoughts with like-minded DIYers about construction techniques and materials. But it was not until recently when I realized that there was aspect of the design I had not really considered.

I had been sharing my thoughts and designs via emails, with like minded DIYer
Yordan and Evgeny of Bulgaria.

In one email, Yordan reported that he and Evgeny had experienced an improvement in sound quality simply by winding the helix in the opposite direction to that initially shown shown on this site, so I decided to investigate.

Putting my photography skills to work I took the following images in an attempt to account for a reason as to why such a noticeable improvement might be experienced, simply by reversing the direction of the Helix winding.


This first image (below) shows the helix being wound in (let’s call it) a clockwise direction.
image[8]

As you can see, the
actual strands of the wire used in the Helix, are crossing the strands in the signal wire at approximately 70 degrees

However - if the helix is wound in the opposite counter clockwise direction (see below), then the angle of the individual strands is much closer to the desired 90 degree angle in order to minimize induced noise even further.

image[12]

Please Note: that before deciding to wind the Helix in a particular direction, you must take into consideration the direction of
the twist of the strands in the actual wire you are using
  • in this case, the strands have been twisted in (let’s call it) a clockwise direction
  • If the wire had a counter clockwise twist - then the helix should be wound in a Clockwise direction to achieve the 90 degree angle.
So Here’s How You Wind It...


This image shows how to wind both the neutral/ground conductors of each and every Helix cable, i.e. provided you are using a wire that has strands twisted in a CLOCKWISE direction as indicated in the images above.


Helix Spiral
  • If the wire used has the strands twisted in the opposite direction, then the Helix should be wound in the opposite direction to that indicated in the above image
The Skeptics Among Us...

This initially included myself, after all, how much of an improvement could this possibly make???

Well, after converting all of my own cables to the counter clockwise twist I was completely surprised to find that the changes were very discernible and contributed to a much improved image and very much improved clarity.

How Anal Do You Wanna Get?

In the images above, I have used the same wire for both live/signal and neutral conductors and as such the twist of the individual strands in both wires is the same. But what if the strands in just ONE wire is twisted in the opposite direction, which direction should the helix be wound in ???

That decision I will leave to the individual. Happy

Personally - I think this level of “detail” is beyond the resolution capabilities of my system, but I felt it should at least be mentioned for those out there that may wish to investigate

Other Observations from Yordan include...

Having had many email conversations with Yordan, he has shared the following observations he experienced, which include:
  1. The cables sound more open when the expandable nylon sleeve i.e. to give the cable a “professional appearance”, is NOT used
  2. The power cables sounded better without spades
    • Personally, on my system I found the spades provided faster dynamics and bass delivery
  3. avoid using heat shrink tubing where it draws the signal and neutral wires closer together
  4. To better isolate the signal (or live) wire use teflon tube - not the expandable sleeve as identified in the web site

NOTE: I have tried a couple of things above, but on my system I did not experience the same observations. But as in Yordan’s case, on your system you could observe improvements by following his tips. so give them a try

So, the Proof of the Pudding...

So, to put Yordan’s
“Helix direction” findings to the test, I rebuilt built all of my Helix cables, this time with the Helix neutral wound in a counter clockwise direction. with everything else being identical.

Right from the very first track it was apparent that the direction of the helix REALLY DOES MATTER!

The image was larger in all dimensions, with the location of musicians being more precise and with more space around them, details and associated clarity improved, dynamic performance was faster, bass performance was faster with more texture and the mid and upper frequencies revealed a new warmth not previously there.

But Was It Easily Discern-able?

To these old ears -
very definitely. I spent over two hours playing the tracks I use to audition cables and components, just so I could hear how much better they sounded with the revised Helix cables.

So there you have it - taking into account the actual direction of the Helix winding has proven beneficial

What if I have already used a Clockwise Helix???

If you would like to correct a cable that has a Clockwise wound helix...
  • DO NOT simply pull the Helix coil straight - this will over-twist the strands inside the wire
  • Remove the Helix coil from the cable i.e. slide the coil off of the live/signal conductor intact
  • Then slide the helix coil onto a suitably sized steel/fibreglass rod - NOTE: you will probably need to compress the coil
  • Finally, pull on one end of the coil, allowing the coil to spin around on the rod
  • this technique prevents the twisted strands inside the wire from becoming deformed
  • You can then rewind the helix in the correct direction without any issues
  • The important thing is that you “UNWIND” the helix coil
  • Otherwise: it may deform the strands inside the wire, which will impact performance
  • NOTE: - power cables are not as sensitive as Speaker cables and interconnects and changing the direction of the Helix does not offer any real discernible improvements in sound quality, so changing their helix direction is not necessary

I have performed this procedure several times and can report that it is actually very easy and a much more effective method than trying to simply straighten a helix coil.

Is all this really necessary?

Well, the choice is yours. The Helix cables will sound extremely good no matter what direction the Helix coil is wound in!

But the improvements achieved on all of my cables by winding the helix in the correct (counter clockwise) direction is the icing on the cake.

Regards - Steve