Time Aligned interconnect and speaker cables - DIY

[Subbu68]

Interesting read Hari.

But not sure of the theory behind no skin effect in Aluminium. If that were the case we power engineers would not go for stranded conductors for power transmission. The switchgear components in transmission / distribution components where aluminium is widely used will have much smaller cross section if there was no skin effect in Al. We would not have had the need to use tubular sections had "core" of a solid conductor conducts at the same current density as the "skin". A complex HV DC transmission with converters, inverters and associated issues was not required for long distance power transmission. Simpler HV AC would suffice. At 50Hz it self skin effect comes to play in Al, so all these measures in power engineering.

As frequency increases the skin depth decreases from what I learnt. And at RF a thin skin is sufficient to conduct than a solid conductor at lower frequencies.

 

[Hari Iyer]

Interesting read Hari.

But not sure of the theory behind no skin effect in Aluminium. If that were the case we power engineers would not go for stranded conductors for power transmission. The switchgear components in transmission / distribution components where aluminium is widely used will have much smaller cross section if there was no skin effect in Al. We would not have had the need to use tubular sections had "core" of a solid conductor conducts at the same current density as the "skin". A complex HV DC transmission with converters, inverters and associated issues was not required for long distance power transmission. Simpler HV AC would suffice. At 50Hz it self skin effect comes to play in Al, so all these measures in power engineering.

As frequency increases the skin depth decreases from what I learnt. And at RF a thin skin is sufficient to conduct than a solid conductor at lower frequencies.

AL conductivity is around 71 compared to 100 of copper and 105 of silver. So that means there are skin affects in AL too. But how effectively you can use it in audio is a question. I have never come across AL used as a plating material yet. There are CCA, silver plated, tin plated and even copper plated copper wires available. I have tried using AL cable as speaker cable, they work as a HF filter, though very marginal and at the music transient can sound shrill. Some good quality tin plated wires are very effective in rolling off HF energy if your setup is bright and shrill. The tin plating need to be non-glossy for this effect IME.

 

[Subbu68]

AL conductivity is around 71 compared to 100 of copper and 105 of silver. So that means there are skin affects in AL too. But how effectively you can use it in audio is a question. I have never come across AL used as a plating material yet. There are CCA, silver plated, tin plated and even copper plated copper wires available. I have tried using AL cable as speaker cable, they work as a HF filter, though very marginal and at the music transient can sound shrill. Some good quality tin plated wires are very effective in rolling off HF energy if your setup is bright and shrill. The tin plating need to be non-glossy for this effect IME.

Al plating is used primarily to prevent corrosion like tin, zinc, chromium etc.

Al will oxidize readily to form Al2O3 that is a bad conductor so it cannot work like silver plating of copper to enhance conductivity. If you looked at new Al conductor used in power lines they shine but in few months they become gray that is the oxide. Al cannot be also soldered. Pure Al or Al alloy conductor is used only where bolted connection or special welding is used.

Tin is basically solder and it's primary aim is to prevent patina forming on copper conductor in marine or wet environments. At the same time conductivity is not affected so much that it does not make tinned copper inferior. Also where Al conductor meets copper (like copper lugs to terminate cables), tinning copper will prevent galvanic cell formation and resultant corrosion else Cu-Al bimetallic strip should be used at the joint. Similarly Gold plating is to prevent corrosion minding that Gold's resistivity is more than copper. So gold plated copper does not enhance the conductivity at the joints or interfaces.

CCA is used to take advantage of lightness of Al but reduce contact resistance at joints due to superior conductivity of copper. Also the cost. Another purpose is to deter theft - pure copper is much more attractive than Al for thieves.

Similarly CCS (steel) is used in earthing to reduce the contact resistance but at the same time to increase the mechanical strength for driving the rods down into earth. They use molecular bonding to bond copper to steel.

So different coating has differing purposes.

How does it affect the transmission of audio signals over a few meters is questionable when the signal is travelling at near speed of light. https://www.wtamu.edu/~cbaird/sq/2014/02/19/what-is-the-speed-of-electricity/

So does the material really affect the speed of HF and LF signals? Can humans differentiate the speed of travel of LF and HF down a 3m wire? Maybe some quantum mechanics is required to explain this.

 

[Bloom@83]

So does the material really affect the speed of HF and LF signals? Can humans differentiate the speed of travel of LF and HF down a 3m wire? Maybe some quantum mechanics is required to explain this.

Apparently, some FMs here with mindblowing alien-technology powered ears can indeed distinguish between transmission speeds of HF and LF over a 3m wire.

 

[Hari Iyer]

Al plating is used primarily to prevent corrosion like tin, zinc, chromium etc.

Al will oxidize readily to form Al2O3 that is a bad conductor so it cannot work like silver plating of copper to enhance conductivity. If you looked at new Al conductor used in power lines they shine but in few months they become gray that is the oxide. Al cannot be also soldered. Pure Al or Al alloy conductor is used only where bolted connection or special welding is used.

Tin is basically solder and it's primary aim is to prevent patina forming on copper conductor in marine or wet environments. At the same time conductivity is not affected so much that it does not make tinned copper inferior. Also where Al conductor meets copper (like copper lugs to terminate cables), tinning copper will prevent galvanic cell formation and resultant corrosion else Cu-Al bimetallic strip should be used at the joint. Similarly Gold plating is to prevent corrosion minding that Gold's resistivity is more than copper. So gold plated copper does not enhance the conductivity at the joints or interfaces.

CCA is used to take advantage of lightness of Al but reduce contact resistance at joints due to superior conductivity of copper. Also the cost. Another purpose is to deter theft - pure copper is much more attractive than Al for thieves.

Similarly CCS (steel) is used in earthing to reduce the contact resistance but at the same time to increase the mechanical strength for driving the rods down into earth. They use molecular bonding to bond copper to steel.

So different coating has differing purposes.

How does it affect the transmission of audio signals over a few meters is questionable when the signal is travelling at near speed of light. https://www.wtamu.edu/~cbaird/sq/2014/02/19/what-is-the-speed-of-electricity/

So does the material really affect the speed of HF and LF signals? Can humans differentiate the speed of travel of LF and HF down a 3m wire? Maybe some quantum mechanics is required to explain this.

The difference is easily noticable at the HF transients which could lead to edgy and sibilant sound. The HF leading edge appears to sound earlier by a few msec ( approx 8 ms to 12 ms) before the LF. If your setup is sibilant then it's due to this. But sibilance can also be due to the characteristics impedance of the cable not matching the source ( amplifier) and load (speaker). This may cause reflections of the signal on the cables back to source. If the CI is matched then the signal is completely absorbed by the load without reflection.

In my cable I have calculated the termination required to mitigate this and am using this across my speakers. This reduce the sibilance by probably reducing the ringing beyond 10 kHz associated due to HF pulse signals which could otherwise sound like flutter echo in severely compromised setups. This also depends on the power bandwidth of the amplifier the load is connected to.

 

[kapvin]

Apparently, some FMs here with mindblowing alien-technology powered ears can indeed distinguish between transmission speeds of HF and LF over a 3m wire.

The difference is easily noticable at the HF transients which could lead to edgy and sibilant sound. The HF leading edge appears to sound earlier by a few msec ( approx 8 ms to 12 ms) before the LF. If your setup is sibilant then it's due to this. But sibilance can also be due to the characteristics impedance of the cable not matching the source ( amplifier) and load (speaker). This may cause reflections of the signal on the cables back to source. If the CI is matched then the signal is completely absorbed by the load without reflection.

In my cable I have calculated the termination required to mitigate this and am using this across my speakers. This reduce the sibilance by probably reducing the ringing beyond 10 kHz associated due to HF pulse signals which could otherwise sound like flutter echo in severely compromised setups. This also depends on the power bandwidth of the amplifier the load is connected to.

Hello Hari,

pardon my rudimentary physics but please help me understand, preferably with as little jargon as possible.

first, here is my understanding:

1. Finally the music is resolved by the listeners ears. so whats most important is at what time the wavefront from each driver hits.
2. Soundwaves travel at approx 342 m/s in mumbai weather. electrical propogation is at some fraction of light speed but definitely more than 3,420,000 m/s so minimum at 10000 times faster. ( for this argument)
3. In a multiway speaker the distance of each driver from the head is different, but you can optimise wave arrival for one listening position (like wilson audio does on their fancier speakers)

my submission is that a 1% difference in sound travel time, will more than offset a 50% different in electric propogation speed, especially for the lengths you mention. which means the perfection that you seek would cease to exist if

1. There is even a millemetric difference is the positioning of the baffle.
2. If you move you head angle by just a little bit or your listening position (again millimetric)
3. Even if the temperature and Relative humidity moves enough to change the speed of sound, the preciseness of your electrical signal will be destroyed by the impreciseness of the wave front.

There are other questions I have, but i wanted to keep this focussed. I understand that there is a lot which I don't understand, and if you have done this research, it must be for a reason, but could you please explain, using as little esoteric jargon as possible.

thanks

 

[Hari Iyer]

Hello Hari,

pardon my rudimentary physics but please help me understand, preferably with as little jargon as possible.

first, here is my understanding:

1. Finally the music is resolved by the listeners ears. so whats most important is at what time the wavefront from each driver hits.
2. Soundwaves travel at approx 342 m/s in mumbai weather. electrical propogation is at some fraction of light speed but definitely more than 3,420,000 m/s so minimum at 10000 times faster. ( for this argument)
3. In a multiway speaker the distance of each driver from the head is different, but you can optimise wave arrival for one listening position (like wilson audio does on their fancier speakers)

my submission is that a 1% difference in sound travel time, will more than offset a 50% different in electric propogation speed, especially for the lengths you mention. which means the perfection that you seek would cease to exist if

1. There is even a millemetric difference is the positioning of the baffle.
2. If you move you head angle by just a little bit or your listening position (again millimetric)
3. Even if the temperature and Relative humidity moves enough to change the speed of sound, the preciseness of your electrical signal will be destroyed by the impreciseness of the wave front.

There are other questions I have, but i wanted to keep this focussed. I understand that there is a lot which I don't understand, and if you have done this research, it must be for a reason, but could you please explain, using as little esoteric jargon as possible.

thanks

I am not interested in discussing with you as you can easily walk to my home and listen for yourself A/B test. You hardly stay 5 km from my home

 

[kapvin]

I am not interested in discussing with you as you can easily walk to my home and listen for yourself A/B test. You hardly stay 5 km from my home

I stay 1500km away. no matter when I listen, and I will seriously try the next time I am in Mumbai, Hari, you have posted this in a DIY section, which is about doing it yourself. i would request you to share in that spirit. and I am not discussing, I am trying to learn. And I am not asking for your secret recipe, i just want clarification of some fundamentals.

 

[Hari Iyer]

I stay 1500km away. no matter when I listen, and I will seriously try the next time I am in Mumbai, Hari, you have posted this in a DIY section, which is about doing it yourself. i would request you to share in that spirit. and I am not discussing, I am trying to learn. And I am not asking for your secret recipe, i just want clarification of some fundamentals.

Kapvin, call me, we can talk. You already have my number.

Any FM want to know more can call me on a weekend.

 

[Anurag]

Its basic MX - Copper with gold plating.

how come are you using a basic copper-gold-pated configuration plug with your complex alloy configuration cable, isn't it going to degrade the effect of your variable configuration? From my experience, the quality of the plug or the solder used affects a lot in the final sound of a cable. eg a local plug vs a neutrik plug vs a furutech copper/gold vs furutech copper/rhodium plug makes a lot of difference.. the local plug is a huge bottleneck for details or refinement or anything else for that matter in the final sound, don't know if you have given a try to better connectors. Also what i found that, the more the different kind of conductors are used in a cable the more the sound starts lacking cohesion, eg "highs are faster than the lows", this kind of experience i have had mostly with silver plated copper cables or silver plus copper combined cables or cables with variable thickness of strands, etc. So, even though this cable suites well your environment, but can it be universally said so, remains the question. Moreover it's the room acoustics that has the maximum effect on the sound/timing/delay and i think this is the area that needs most of the tuning, so would be good to know if you have ever measured the delay time of your listening environment and if so then knowing the results would be good to give us some perspective.

 

[Hari Iyer]

how come are you using a basic copper-gold-pated configuration plug with your complex alloy configuration cable, isn't it going to degrade the effect of your variable configuration? From my experience, the quality of the plug or the solder used affects a lot in the final sound of a cable. eg a local plug vs a neutrik plug vs a furutech copper/gold vs furutech copper/rhodium plug makes a lot of difference.. the local plug is a huge bottleneck for details or refinement or anything else for that matter in the final sound, don't know if you have given a try to better connectors. Also what i found that, the more the different kind of conductors are used in a cable the more the sound starts lacking cohesion, eg "highs are faster than the lows", this kind of experience i have had mostly with silver plated copper cables or silver plus copper combined cables or cables with variable thickness of strands, etc. So, even though this cable suites well your environment, but can it be universally said so, remains the question. Moreover it's the room acoustics that has the maximum effect on the sound/timing/delay and i think this is the area that needs most of the tuning, so would be good to know if you have ever measured the delay time of your listening environment and if so then knowing the results would be good to give us some perspective.

My current plugs are chrome plated on copper. I am planning a gold plated Amphenol later. Different conductors are btw used to prevent time smear and group delay.

I am sure you have not read the patented article - else you must have not quoted. Using only silver plated wire will cause HF to be ahead of LF by atleast 8ms to 10 ms - read the article. Adding nichrome or tin of a proper awg size will slow down the HF to align them in time with LF and prevent time smear.

I use an OB loading - so much of the side walls affect are taken care off. For the front wall dispersion a parabolic reflectors combined with a felt + diffuser immediately behind the FR drivers address the reflected waves by allowing early reflection.

Delay is measured from the impulse response and is not very accurate in reflective rooms. An anechoic chamber is preferred. It also depends upon cable used, baffle profile, position of the drivers on the baffle and if the driver voice coils are aligned in time. Using different conductors could help to delay HF in time w.r.t MF/ LF. I am still in the learning process and nothing is conclusive and hence so much of writing. Once I learn 100% all writings automatically stops as you have reached Nirvana.

I am still contemplating using my silver plated copper wire for my woofer to speed up LF, use copper wire on my FR drivers and use a tin plated copper wire on my Telefunken tweeter to slow down HF. Only testing can prove this concept - as the length of wires involved are miniscule to have any reasonable time delay. But an experiment will confirm that.

 

[Anurag]

I am sure you have not read the patented article - else you must have not quoted. Using only silver plated wire will cause HF to be ahead of LF by atleast 8ms to 10 ms - read the article. Adding nichrome or tin of a proper awg size will slow down the HF to align them in time with LF and prevent time smear.

will surely read your article, although i can already get what you are trying to achieve. but a concern is, injecting conductors which are less conductive to get your preffered balance hopefully dosent have some side effects or a sound that is too personal in taste.

 

[drlowmu]

I have not been following every twist and turn of this thread Hari.

A few comments from my perspective, if I may say this :

What you, and other people need to realize, about you " hearing things " is that your audio system is different and unique, VS anyone else's in India.

You were sent in 2020, when you built your SE DC KT88 amp, four GTO caps, Arcotronics 5 uF at 1,200 VDC. These GTO caps are used to bypass the filtering to your KT88 B+ stage. Across C1 and C2, two GTOs in each monoblock.

A GTO, and only a GTO in our experience thus far, allows one to UNIQUELY hear the leading edge of transients, seemingly totally defined, ......... unlike ANY other capacitor in audio. This is a unique listening advantage you now enjoy.

You also hear the music " in the time of the music " by having a L.S.E.S. power supply ( low stored energy supply ), unlike others in India.

You also use dual directly heated tube rectifiers, which likely very few people, if any, in India use. A directly heated rectifier is instantaneous in response to the music, in comparison to a indirectly heated rectifier,....( which is a more common tube rectifier, utilizing a cathode. )

Living half way around the globe from you, I have never had the advantage to hear your amplifier. Even though we share similar circuits and some similar parts, there is no way for me to tell what you have made. But I DO know from my own building and experimenting, what each of the three areas commented on above, do special.

I am not one to judge what you are doing in audio, with wiring, or..... if it is good or bad. Time will tell I believe.

I do want to encourage you to promptly optimize the internal AC polarities, inside each monoblock, as per my posting on HFV. Do not take this optimization for granted, and put off doing it. The end result is special !!

Keep up the good work, and thank you for your clear reporting.

Jeff

PS : Instructions, on how to AC polarity optimize your own SE DC KT88 amp, are inside this following recent thread, entitled " The Last 1% " :

Final Photos and Final Testing, stereo 6005 SE DC amp from 2021

First order of business , a public apology to Yogibear. There was a mistake, in that I initiated a written private email apology to Yogibear ( Samir ) on 2-09-2022, with a CC to Hari Iyer. This apology was totally my own unsolicited idea. He deserved it. Somehow it seems, Yogibear had...

www.hifivision.com

Have fun !!

 

[Hari Iyer]

I have not been following every twist and turn of this thread Hari.

A few comments from my perspective, if I may say this :

What you, and other people need to realize, about you " hearing things " is that your audio system is different and unique, VS anyone else's in India.

You were sent in 2020, when you built your SE DC KT88 amp, four GTO caps, Arcotronics 5 uF at 1,200 VDC. These GTO caps are used to bypass the filtering to your KT88 B+ stage. Across C1 and C2, two GTOs in each monoblock.

A GTO, and only a GTO in our experience thus far, allows one to UNIQUELY hear the leading edge of transients, seemingly totally defined, ......... unlike ANY other capacitor in audio. This is a unique listening advantage you now enjoy.

You also hear the music " in the time of the music " by having a L.S.E.S. power supply ( low stored energy supply ), unlike others in India.

You also use dual directly heated tube rectifiers, which likely very few people, if any, in India use. A directly heated rectifier is instantaneous in response to the music, in comparison to a indirectly heated rectifier,....( which is a more common tube rectifier, utilizing a cathode. )

Living half way around the globe from you, I have never had the advantage to hear your amplifier. Even though we share similar circuits and some similar parts, there is no way for me to tell what you have made. But I DO know from my own building and experimenting, what each of the three areas commented on above, do special.

I am not one to judge what you are doing in audio, with wiring, or..... if it is good or bad. Time will tell I believe.

I do want to encourage you to promptly optimize the internal AC polarities, inside each monoblock, as per my posting on HFV. Do not take this optimization for granted, and put off doing it. The end result is special !!

Keep up the good work, and thank you for your clear reporting.

Jeff

PS : Instructions, on how to AC polarity optimize your own SE DC KT88 amp, are inside this following recent thread, entitled " The Last 1% " :

Final Photos and Final Testing, stereo 6005 SE DC amp from 2021

First order of business , a public apology to Yogibear. There was a mistake, in that I initiated a written private email apology to Yogibear ( Samir ) on 2-09-2022, with a CC to Hari Iyer. This apology was totally my own unsolicited idea. He deserved it. Somehow it seems, Yogibear had...

www.hifivision.com

Have fun !!

I do concur that the DC SET KT88 monoblocks are very different from other amplifier design topologies.

 

[Hari Iyer]

Yesterday an direct A/B comparison was done with Audioquest Green cables and this DIY interconnect. I am glad to say that AQ was no match for my DIY cable. Gives me more confidence on my DIY journey.

 

[RtoR King]

Interesting read Hari.

But not sure of the theory behind no skin effect in Aluminium. If that were the case we power engineers would not go for stranded conductors for power transmission. The switchgear components in transmission / distribution components where aluminium is widely used will have much smaller cross section if there was no skin effect in Al. We would not have had the need to use tubular sections had "core" of a solid conductor conducts at the same current density as the "skin". A complex HV DC transmission with converters, inverters and associated issues was not required for long distance power transmission. Simpler HV AC would suffice. At 50Hz it self skin effect comes to play in Al, so all these measures in power engineering.

As frequency increases the skin depth decreases from what I learnt. And at RF a thin skin is sufficient to conduct than a solid conductor at lower frequencies.

The reason I was told for tubular aluminum conductors in sub stations is mechanical, not electrical or skin effect related. HV insulators to support long runs are expensive and another flash over failure point to consider. With the rather low current in these cables, a few hundred amps, a solid conductor would be too thin to support it's self. So by using aluminum tubing, you get a rigid conductor that needs less insulator supports and because of the current demands, tubular conductors are a great weight compromise.

 

[Subbu68]

The reason I was told for tubular aluminum conductors in sub stations is mechanical, not electrical or skin effect related. HV insulators to support long runs are expensive and another flash over failure point to consider. With the rather low current in these cables, a few hundred amps, a solid conductor would be too thin to support it's self. So by using aluminum tubing, you get a rigid conductor that needs less insulator supports and because of the current demands, tubular conductors are a great weight compromise.

Not just mechanical as you described also skin effect and cost. I was a substation designer in the past and later a consultant supervising and managing EHV substation projects (total span of 28yrs)

In transmission systems they carry a couple of kA not a few hundred amps. So any reduction in ohmic loss or impedance drops is welcome.

 

[RtoR King]

Not just mechanical as you described also skin effect and cost. I was a substation designer in the past and later a consultant supervising and managing EHV substation projects (total span of 28yrs)

In transmission systems they carry a couple of kA not a few hundred amps. So any reduction in ohmic loss or impedance drops is welcome.

I just fail to see mathematically how skin effect is at all relevant in a sub station at 50/60hz? Now if we are talking transmission lines and hundreds of miles, perhaps.

 

[Subbu68]

I just fail to see mathematically how skin effect is at all relevant in a sub station at 50/60hz? Now if we are talking transmission lines and hundreds of miles, perhaps.

A solid bar with no current in the middle, so why to spend on it? And busbars rated for 4000A, even a few milliohm increase in ac resistance is going to add to system losses.. it may not matter much in a small industrial s/s but very much in transmission stations where you need a bicycle to get from one end to the other.