length of interconnects for passive preamp


I understand that when using a passive preamp short interconnects are recommended. I have two questions before I purchase them: Does that short length requirement apply to both the ic between the source and passive as well as the passive and the amp? And regarding the length itself, is the shortest always best? I see that some companies offer a 1 foot or even 6" length - which I could use, although it would require some serious rearranging of my equipment; but will those very short lengths provide a noticeable improvement over a 1.5 meter or 2 foot ic? Not sure if there is a rule of thumb. Many thanks!
majorc

@holmz - the cables I provided links too in my previous post are great examples of a very good commercial cables. There are better, but these provide best bang for the buck from a commercial brand

However the "specification" for the DIY cables I have developed (with the help of many others) would make an excellent cable because they employ

  • either UP-OCC solid copper or UP-OCC solid Silver signal wires
    • these are the best conductors available for DIY projects at present
  • With oversize Teflon tube insulation
    • the internal diameter needs to be 25% to 30% larger than the diameter of the wire
    • using an oversize tube allows an air gap between the wire and the Teflon
    • the resulting effective Dielectric Constant value is very close to air at 1.1
      • this produces a very low noise floor cable
  • UP-OCC solid copper Helix coil neutral
    • the Helix also helps lower noise floor of the cable
    • it minimizes induce noise between signal and neutral conductors
  • silver coated pure copper low mass RCA plugs
    • KLE Innovations Absolute Harmony
    • or Perfect Harmony RCA’s
  • see this link for the Helix DIY cables

The problem with Bulk cables is they employ a conventional cable geometry with insulation that are bonded to the wires. This all contributes to noise being generated by the actual cable.which clouds micro details

Bulk cables also tend to use OFC copper, but the best metal for the wire currently (i.e. for DIY purposes) is UP-OCC silver and UP-OCC copper

If you want to read aabout what others think of the Helix cables take a look at this thread

https://forum.audiogon.com/posts/2350463

If you want to proceed with a bulk cable than I would recommend this one

Hope that helps - if you have any questions about the Helix design just ask - I;m glad to assist

Regards - Steve

None of that makes any sense.
Maybe it might, but with a spec, the one can determine something.

  • capacitance is given in Farads (milli, micro, nano or Pico farads)
  • inductance in Henrys (Milli, Micro, nano, Pico)

What you give seems sort of like BS… in nice words.

And that link that you posted does not have any specs… so going with Mogami, Canare, etc. would let people base their purchase on some meaningful specs.

 

Shorter is also a good practice with a passive-Pre to get the capacitance and inductance numbers as low as possible.

@holmz - My apologies - what I provided are the Phyical cable specs, which to me are the most important - i.e.

  • type of wire
  • type of insulation i.e. dielectric characteristics
  • cable geometry

But since you asked so nicely, here are the electrical specs

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

  • Capacitance = 32 pF
  • Inductance = 0.8 uH
  • resistance is negligeable

WRT your statement

What you give seems sort of like BS… in nice words.

When you have time - take a look at the In-akustik website, because they display their geometry in detail and so does Zavfino.

Also, take a look at these links that talks to the many aspects of cable design

https://www.psaudio.com/article/cables-time-is-of-the-essence-part-1/
https://www.psaudio.com/article/cables-time-is-of-the-essence-part-2/
https://www.psaudio.com/article/cables-time-is-of-the-essence-part-3/

I have provided my opinions as to what goes into designing and building excellent cables. They are based on exeprimentation and observation over many years and with the input from many other people

  • you are free to do what you want with the information I have provided
  • If you believe it is B.S. so be it
    • I am NOT here to convert.

BTW - I stopped using Mogami, Canare and even Van den Hul many years ago because they did not provide the level of performance that I was looking for !

They are quite good for live performances - where high gain amplification is used, BUT they are NOT the best solution for Home audio

  • they are however very affordable, which will attract many people.

 

Regards - Steve

Thanks @williewonka I’ll try to keep my tone civil.

Geometry:

  • One of the 3 PS links mentions woven cables, which sound like what the Kimber 4TC and 8TC are.
  • And you also mention the silver gold Mundorf.
  • Is that a single solid core?
    • and… are you saying that the multi strand is something you shy away from?

Insulation

  • I see PTFE and also bare wire.
  • Are you using a different cotton over the bare wire?
  • And then in your earlier talk about an air gap… Are you “twisting the pair”?
    • Wouldn’t that reduce the gap to zero where the +/- sit ‘side by side’?

 

The other thing that the 3 part PSaudio mentioned was time errors. Does reducing some of the cable issues even help in a speaker that is not phase or time coherent?

https://www.mundorf.com/audio/en/shop/Cables/MConnect_SGW/

@holmz - WRT wire types - i.e. Stranded vs. Multi-strand vs. Solid

Stranded wires do not provide the same level oif dynamic performance and clarity that solid wires do, but that does not mean I do not use them - I use them for the neutral conductors of Speaker and Mains cables because they improve cable flexibility

Stranded wires

  • In stranded wires, each strand has a finite numer of valence electrons availlable to provide for the transfer of electrical energy
    • as that limit is approached (due to increased power levels), electrons start to jump between trands,
      • this generates HEAT and NOISE
      • and is why stranded wires do not perform as well as solid wires
  • A solid wire has a much higher current carrying capacity than the same gauge stranded wire
    • so it is better equiped to handle those large transient peaks
    • This is why I choose to use solid wires for the signal (or Live) conductors in all cable types
  • But stranded wires ARE very good for the delicate signals in Tonearm wires/cables
    • because all they are really "conveying" is very small changes in voltage
      • i.e. the current is extremely small
      • the smaller the current, then the impact of the dielectric effect of the insulation on that wire becomes negligeable
      • hence - crystal clear transfers are achieved
  • I have tried stranded wires for the signal (or live) conductors in all cable types, but the solid wires sound significantly better
  • But when the use of a cable requires better durability e.g. my more mobile guitar amps - then I scafrifice cable perofrmance for safety and durabliity

Multi Strand conductors

  • I make this distinction, because I have compared a Single solid wire to conductors made from multiple solid strands (i.e. up to 4 strands of solid wire) in both power cables and interconnects
    • The optimum appears to be 2 strands - for reasons I am yet to understand, but I have tried the following...
      • Tightly twisting two strands of bare wire before inserting the wires into a single Teflon tube
      • inserting each wire into their own Teflon tube and twisting them in a more relaxed twist (i.e. one complete twist every 3-4")
      • the latter providing the best performance

Single solid wires

  • My initial cables used just a single strand of wire for both signal and neutral conductors and then another Audiogon member suggested I try the "Double Shotgun" approach
    • i.e. using two wires for each conductor, referred to as the Double/Double
    • This proved to improve overall performance
  • But being curious, I decided to try a two wire Signal conductor with a single wire neutral conductor known as the Double/Single
    • I also tried a larger gauge neutral to compensate for the loss of gauge in the neutral conductor
    • Whilst provding very good performance it did lack a little body comapred to the Double/Double
      • But it is cheaper and easier to fabricate
  • which brings me to my latest adaptions
    • A Double/Double cable that has...
    • for the signal conductor
      • 2 x 20 gauge solid UP-OCC silver wire
      • each bare wire is inside it’s own Teflon tube and twisted together in a relaxed twist
    • for the neutral conductor
      • 2 x 18 gauge solid UP-OCC copper wire
      • each bare wire is inside it’s own Teflon tube and formed into the Helix coil
    • this geometry provided stunning performance that exceeded my expectations
    • I also tried a second Double/Single cable that has a neutral Helix Coil made from 1 x 16 gauge solid UP-OCC copper wire
      • to my amazement I could not discern any significant improvement on my system and with my ears
      • This may not be the case on systems with higher resoultion capabilites

 

INSULATION(s​)​​​​​​

I started investigating insulations a couple of years ago after trying Duelund Tinned Copper, becasue it made no sense to me that people preferred Tinned Copper over Solid silver

  • it was at that time that I discovered some content on the web that explained about Dielectric Contant (Dk) of different insulations and their impact on signal propagation
  • this was an eye opener and explained why the Dulund wire was prefered - the Cotton/Oil insulation proved better clarity and imaging
    • the followigis a list of Dk values of different insulation tyoes
      • Vacuum = 1.0
      • Air = 1.1
      • Cotton 1.3
      • Foamed Teflons - 1.45
      • Teflon - 2.2
      • PVC’s, rubber ect.. > 4.0
  • Fast forward to the bare wire in teflon tube
    • provided you use a tube that has a 25%-30% larger inside diameter than the diameter of the wire, the teflon tube does not collapse around the wire when a gentle twist is used - there is only ever one very small point of contact
      • this makes value of Dk very close to Air at 1.0
      • this technique provides exceptional clarity of signal tranafer, which translates to more details
      • having more details also improves imaging - not only in a larger more well defined image
        • but it improves the clarity of the various layers of instruments and artists within the image.

WRT

Wouldn’t that reduce the gap to zero where the +/- sit ‘side by side’?

The DIY Helix cables take a very different approach to Cable Geometry

  • the +ve and -ve conductors DO NOT sit side by side
  • the neutral conductor is wound into a helical coil (or Helix)
  • the signal (or live) wire is inserted down the center of the coil
  • this means the coiled conductor crosses the Signla conductor at close to 90 degrees
    • this mitigates any/all NOISE that would otherwise be induced into the neutral conductor from the signal conductor
      • NOTE: Any noise on the neutral wire is actually transfered back into the neutral side of the connected component’s circuitry, which causes distrtions in the signal that are amplified by that component
    • The mechanics are more fully explained in this link

WRT:

Does reducing some of the cable issues even help in a speaker that is not phase or time coherent?

This type of problem could be due to

  • crossover design
  • choice/combination of drivers
  • enclosure design

But having said that - cables that have parametric extremes (either low or high) in levels of Capacitance and/or Inductance might display this type of degraded sound when used with with speakers having similar high values of Capacitance or Inductance.

Speaker Design is one area that I tend to shy away from just because of the complexities involved.

But when I try new speakers (which is NOT very often) I take along my cables and amp 

But the Capacitance and Inductance parameters of the Helix design tend to be "middle of the road" and I have not yet learned of any problems in systems to date

The only restriction of the Helix design is

  • they DO NOT provide optimum performance in the following cases
    • Speaker cables should NOT be used in conjunction with amplifiers that have adopted a symmetric balanced design
      • i.e. where the speaker +ve and -ve terminals carry the same signal, but 180 degrees out of phase
    • Power cables should NOT be used in conjunction with Power supplies or providers that have Balanced Outputs
      • i.e. where the Live and Neutral carry the same signal, but 180 degrees out of phase - this includes:
        • Certain power conditioners adopt this approach
        • Norway, where the entire power grid is balanced

NOTE: With the Helix Cable geometry

  • There appears to be no impact related to the shortness of a cable.
    • e.g. I have used Digital RCA cables as short as 18"
      • But I did use the KLE Innovations Harmony RCA plugs
    • I also know of USB cables that are 36" long and work extremely well
    • I also have a mini System that has 12" long speaker cables and a 30" power cable and the improvement in sound was amazing

My apologies for the very long post - but as you can see it gets very compoicated

Regards - Steve