* HELIX Q & A

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 in the table

e.g. if YOUR speakers cables are 2 meters long then the numbers can be estimated as follows...

Capacitance: 181 / 3 x 2 = 120pf
Inductance: 3.2 / 3 x 2 = 2.13 uH
X
L @ 20 kHz: 0.402 / 3 x 2 = .268 Ohms


Specifications

Loop Inductance - is measured across the cable at one end, while shorting cable at the other end,


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 60 pF/meter capacitance 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 1.1 uF/meter inductance 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 own a NAIM amp and the cables appear to work 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

The Helix “numbers” are Middle-of-the-road for each cable type, but based on feedback from others who have tried them, they appear be a good match to a lot of audio components. (see “
IMPORTANT:” below) and will minimize many of the effects that conventional 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.

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.

As opposed to the generally accepted audio industry standard of
20Hz and 20kHz

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

And 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 these cables may NOT be for you.

There is some debate as to whether the additional 5% (of the speaker impedance) on top of the actual speaker’s impedance would be noticeable. e.g.,
  • my speakers have an impedance of 6 Ohms
  • 5% of 6 is 0.3 ohms
  • if I look at the impedance of the my 3 meter Helix cables from the table above = 0.402 Ohms @ 20kHz
  • So - If I could hear a 20kHz signal I “might” detect a tiny drop in volume
  • BUT - my hearing ability has diminished over the years, so taking the 12kHz value of 0.241 Ohms
  • I am well within the 5% margin
  • BUT AGAIN - this is not a hard and fast rule, simply because the crossover employed in the speaker may have a significant impact on whether any cable will sound good - OR NOT!
  • I have not heard of any negative feedback from any of the people that have tried Helix cables in systems ranging from sub $1000 systems, to systems exceeding $70,000

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

OTHER STUFF:

I have also observed that the Helix design actually enhances the operation of the components they are connected to.

e.g. most of my components run a few degrees cooler than with other cables


So right about now you might be thinking that these issues only apply to areas where the voltage and current is of significance, as in power and speaker cables, but regardless of cable type...

ALL CABLES ARE AFFECTED !

HELIX Q & A

Over the years I have often been asked a few questions repeatedly, which hopefully I have answered below.

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 10 gauge Live conductor with dual 12 gauge neutral and ground conductors works the best
  • For source components I have found that 10 gauge provides no benefit, so I use a 12 gauge Live conductor with dual 12 gauge neutral wires and a 12 gauge ground wire conductors works the best
  • However, for some components, such as a TV, a 14 gauge neutral conductor with dual 14 gauge neutral wires and a 14 gauge ground wire works very well.

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 to work loose over time.
  • Not only are spades an important safety consideration, they do actually improve performance

Interconnect cables:

Can the Helix Cable be used for connection between the Turntable and the phono stage?
  • Absolutely - the Helix spiral provides excellent shielding for the delicate audio signal from cartridges
  • I would recommend using 28 gauge wire for the signal and three 20 gauge conductors for the Helix coil


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

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?
  • Yes - it will change the capacitance and inductance of the cable
  • This may not be too much off an issue for the components you are using, but you should be aware of these changes.

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