*HELIX IMAGE APPROACH

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

This Page is an overview of the very latest developments and updates to the Helix Cable Geometry
Last Update: 8 June 2021.
This latest development contains an "adaption" of the Helix Speaker cable to accommodate amplifiers that utilize a balanced symmetrical design in their output stage.

The previous developments feature an update to the wire now used for the Helix Coil (Neutral) conductor.
I now use wire made from Teflon insulated UP-OCC Copper, in both stranded wire
(for Power and Speaker cables) and solid wire (for interconnects).

This is the first wire I have tried that provides a significant and very noticeable improvement in sound quality

NOTE: For Helix Cable/Component compatibility
- please see HELIX Q & A

During previous developments, it was quite noticeable that selecting wires that had an insulation with a low
Dielectric Constant (Dk) for the signal or live wires only resulted in improved sound quality

Dielectric Constant (Dk)…
  • Dielectric constant, property of electrical insulating material (which is 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.
  • PVC: Dk = 4.0
  • Teflon: Dk = 2.2
  • Foamed Teflon (AirLok): Dk = 1.45
  • Cotton: Dk = 1.3
  • Air: DK = 1.1

So the challenge was: how to get the Dk as close as possible to the value of Air?

The adaption to the insulation can be found here…

The HELIX IMAGE (Air)


Applying this approach to the insulation of the Live or Signal wires of HELIX IMAGE cables resulted in improvements to every single metric we use to assess system performance…

  • Dynamics, Clarity, Details, image size, image focus, space around performers
  • outstanding clarity and details together with improved precision within the image
  • the depth of the bass was deeper with improved textures.

For Fabrication details please see …

I am currently using HELIX IMAGE (Air) cables and can report that the modifications have resulted in significant and easily discernible audible improvements over the older design.
I have listed a few options of wires that can be used for the signal and neutral wires in the detailed fabrication instruction, 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.

Previous adaptions to the HELIX Cable are courtesy of:
  • long time contributor on the Audiogon Forum: Member Name: Grannyring (i.e. Bill) - for his Schroeder Double Shotgun approach
  • Ernst of Austria - who first brought my attention to the importance of Dielectric Constant
  • Yordan & Evgeny of Bulgaria - who test numerous wires containing different metals and insulations
  • Todd (US) for developing the first bi-wire version of the Helix speaker cables
  • also, Ghislain (Canada), John (USA) and many others.

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

“The HELIX IMAGE (Air)” - 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


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

Regards - Steve

The HELIX IMAGE (Air)

NOTE: This page ONLY describes the process of insulating the Signal or Live wires of the Helix IMAGE cables.
  • strange as it may seem, you DO NOT have to apply this insulation guide to the Neutral wire

Links to the pages on how to build the individual cables can be found at the bottom this page


So How do you build a conductor that has Air as the dielectric?

Teflon tube has been a long time favourite in my cables (early on) so I looked back a previous versions of the cables and realized if I used the right sized tube it would allow enough air around the wire and result in a very small area of contact.

I selected a PTFE Tubing with Internal Dia = 0.106" and Outside Dia = 0.130" - from Take Five Audio

This tube can be used for either
  • a single 14/12 gauge wire when used to fabricate the Signal or Live wires for the speaker cables and power cables
  • or the 2 x 18 gauge (for Interconnects) and the 2 x 16 gauge (for SOURCE power cables)
  • so basically, this teflon tube it is suitable for all Interconnect, speaker and mains cables

Looking at the diagram below, of the cross section of a Live conductor of a mains cable and a twisted pair signal conductor of the interconnect cable it is quite clear that provided the tube does not collapse there is only ever ONE point of contact with the teflon tube, with lots of air around the actual wire

This is the value Teflon has over Cotton and Silk sleeves, because cotton and silk tend to collapse around the wire resulting in multiple points of contact, increasing the value of the Dk



00 cross section


Unfortunately, the UP-OCC copper I have been using from both Neotech and VH Audio both have insulation that must first be removed, but bare UP-OCC wire can be purchased from retailers such as Part Connexion

In order to remove the insulation with a minimum of effort I inserted an eye ring in the end of a piece of wood (see below) to make a simple striping jig

  • Thread the wire through the eye ring
  • hold the wire on the board at the other end of the board
  • Place the blade of a utility knife on the wire and lift the blade to about a 5 degree angle
  • and simply cut a small sliver of insulation from the wire
  • then peel the insulation from the wire


01 board

The rest of this process depicts how to fabricate the Signal conductor for the Helix interconnect
  • which uses 2 x 18 gauge wires
  • but the same process can be applied to any HELIX IMAGE (Air) Cable



FOR the 2 x 18 gauge Interconnect SIGNAL CONDUCTOR

AND the 2 x 16 gauge Source Power Cables LIVE CONDUCTOR


Strip the insulation from the two wires (as shown above) and twist one end tightly to hold the wires together

02 twist tight

Then twist the two wires together at the rate of about one complete twist every 3-4 inches

And twist the last 1/2" or (centimetre) to prevent the wires from untwisting, as below


03 twist loose

Then insert the tightly twisted portion into a drill chuck and hold the other end with a pair of pliers

04 drill

Rotate the drill clockwise i.e. clockwise as you look down the wire from the rear of the drill

Rotate until the wire is evenly twisted - approximately 3 twists per inch - as below


05 Drill Twist

Remove the wire from the drill chuck - it will remain twisted, but tightly twist the end to match the the opposite end

Then "TIN" the wire with solder for about 1" at each end - this prevents oxidation outside the Teflon tube


06 tin ends

Insert the wire into the teflon sleeve and apply a small piece of heat shrink tubing that has the adhesive on the inside

An optional alternative is to seal the ends with hot glue

This seals the tube and prevents air flow and prevent oxidation of the bare wire


07 seal ends

FOR the 2 x 16 gauge Speaker Cable SIGNAL CONDUCTOR

AND the 2 x 14 gauge (heavy duty) HD Power Cables LIVE CONDUCTOR


A similar process is required, except that each of the two wires is inserted into it's own tube and then gently twisted as shown below
i.e. approximately 1 complete twist every 4" (10cm)

Speaker-Live


The Power Cable LIVE conductor is terminated with a spade and both tubes are sealed with a single piece of Heat Shrink as show below.
Only attach the speed at one end to allow for easy insertion into the Helix Coil and then attach the other spade



Power term

Using this technique, a view of a cross section of the twisted pair conductor reveals…


Twisted Pair X


This provides an additional benefit when the twisted pair conductor is placed inside the Helix Coil of the speaker cables





No Beads

If desired the conductor assembly can be placed inside a cotton sleeve for improved vibration control, but it is NOT required


So why prevent air flow?
  • In order to prevent the bare copper wire (or silver) from oxidizing
  • Initially some oxidation will occur and a little dullness will result
  • but based on my current speaker cables which have been in place for about 4 months, the dulling of the copper appears to have stopped

I was initially very concerned about oxidation because if it was a real issue it meant people would be faced with re-wiring their cables once they turn green.
  • But on thinking about the oxidation process further, those copper weather veins on buildings generally take about 5 - 7 years to obtain the green patina
  • they are open to the elements 24/7.
  • Also, the bare ground wire in my house (that connects to the water supply) is still pretty bright after 4 years
I believe sealing the wire inside a Teflon tube using the approach above will protect the wire from oxidation for a considerable period of time. i.e. many years

In recognition of the superb performance achieved by applying this technique I have decided to name this versos of the HELIX cables…

The HELIX IMAGE (Air)


When this approach is used on all Helix cables the results are stunning !!!


So In Summary

  • Interconnect Cable Signal Wire is 2 x 18 gauge UP-OCC twisted wire inside a single Teflon Tube
  • Speaker Cable Signal wire can be either 2 x 16 gauge or 2 x 14 gauge, where each wire is in it's own Teflon tube with a gentle twist
  • Source Power Cable Live wire is 2 x 16 gauge twisted wire inside a single Teflon Tube (see warning below)
  • HD Power Cable is 2 x 14 gauge Live wire where each wire is in it's own Teflon tube with a gentle twist
  • The neutral and ground wires are unchanged from the original design

WARNING: You may be tempted to use a single tube on the speaker cables if using 2 x 16 gauge wire, but it becomes increasingly more difficult to insert the twisted conductor into the tube after about 4-5 feet

This technique can be applied to any of the following HELIX IMAGE Cables…
Interconnect Cable...
USB Cable...
Speaker Cable...
Power Cable...

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

Are Helix Cables compatible with all components ?

Interconnects: to my knowledge ALL Helix Interconnects are compatible with all components

Speaker Cables: Helix Speaker Cables should NOT be used with amplifiers employ a Symmetrical, Complimentary, or Balanced outputs.
i.e. Both terminals effectively carry the same signal, just 180 degrees out of phase, similar to a balanced Interconnect

Amps known to employ this architecture:
  • Accuphase E-303
  • Anthem - Some Models
  • Atma-Sphere - all models
  • Audio Research - Some Models
  • Ayre - all models
  • Balanced Audio Technology
  • BAT VK-255SE
  • Boulder 500AE
  • D’Agostino - Some Models
  • Musical Fidelity - High End Models
  • Pass Labs
  • PS Audio BHK Signature 300
  • Vitus
  • Yamaha some models

However: after giving this some thought, the following adaption would work very well.

Balanced Speaker cables

  • Each signal conductor (i.e. +ve and -ve) would be 2 x 16 or 2 x 14 bare UP-OCC solid copper.
  • Each wire would be inside it's own teflon tube and then gently twisted with connectors attached
  • OPTIONAL: That assembly could then be inserted inside a cotton sleeve for further isolation
  • The Helix coil would be wound from any generic12 gauge stranded or solid copper from any electrical store
  • The coil remains unconnected at the speaker end of the cable
  • The Helix is there only to act as a "spacer" for the signal wires
  • and provide a "Faraday Cage" around the signal conductor to reduce the impact of RFI/EMI
  • The Ground Pigtails would be 18 gauge stranded copper with insulation and added to the power cable for that amp.
  • An alternate approach would be to connect the Helix Neutral to a pigtail lead from the ground pin (only) of a mains plug and insert that plug into an available socket

At this point you would have one cable assembly for the +ve conductor and a second for the -ve conductor
  • To make it look more conventional (i.e. a single cable)
  • each cable assembly could be inserted into an expandable nylon sleeve over the Helix section of the cable
  • and then both cable assemblies (with sleeves) could be inserted into a larger expandable sleeve to make a single cable assembly

NOTE: this solution would work for all the amps
i.e both Symmetrical Balanced AND Single Ended designs



Power Cables: Helix power cables should NOT be used in conjunction with a power conditioner that provides a "balanced output",
i.e. where both Live and Neutral carry the same voltage - just 180 degrees out of phase.

e.g. Equitech Corporation pioneered power conditioning of this nature.

How can you tell if YOUR power conditioner uses this approach?

  • simply measure the voltage between the Ground and the Neutral and then the Ground and the Live
  • if they show the same voltage then the power output is balanced.

NOTE: connecting a helix speaker cable or power cable to one of the incompatible components listed above WILL NOT cause harm.
  • But the sound will not be optimal

Other Issues: A problem of HUM was reported using a Helix Power Cable with a Canary Grand Reference amp, but the cause is yet to be determined

Please note this is NOT an exhaustive list and I will endeavour to keep it updated as I find out about other anomalies



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%
  • The best 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

With Respect to 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

With Respect to 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.
  • WARNING: HELIX Speaker cables WILL NOT work with amps of a fully balanced "Symmetrical" design, such as the the Vitus and some fully balanced designs from Musical Fidelity

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