Tube buffer made with high end components

[johnmicheal]

This is Tube buffer I build with Brimar CV4003 12AU7.
All the load line and safety factor considered while designing.
Sound is very lush and warm with huge soundstage and instrument separation,
Silky smooth.
Please see attached video.
Comments are welcome.
I have Mundorf Supreme 4.7 uF capacitor ,which I will try on weekend for output coupling capacitor.

Pictures attached

 

[drlowmu]

The red and black twisted set of wires, from the volume control, to the white middle-of-the board inter-stage film caps, needs to be totally UNtwisted.

Do not twist these two signal wires together at all. Separate the wires so that their low signal level fields can not interact with each other.

As wired, it is degrading the highs, a sense of openess, and general fidelity. This occurs when these two wires, the audio signal from opposite channels, touch each other just one time, let alone the twenty or so twists you have instituted.

Please, importantly, A-B it !!! Tell us all - what you hear !!

DO report back to all of us F.Ms, so people will learn from your work .

Allow use-time for the parts and solder joints to break in, by playing music, before switching out parts and critically evaluating them before they are broken in.

Thanks,

Jeff

 

[johnmicheal]

Thanks Jeff, I will do the change. This is porotype version ,not the final one.

 

[Yogesh]

Thanks Jeff, I will do the change. This is porotype version ,not the final one.

Will you give away prototype when you make final version?!

Great Build by the way! Looks Awesome too.

 

[drlowmu]

Thanks Jeff, I will do the change. This is porotype version ,not the final one.

Good, please tell us what you hear !!

I wish they would have put some local ( film cap ) B+ storage right on the audio boards, right at their points of use.

Only two or three microfarads will do it, for each triode plate. Shoot for close to zero lead length of the cap, connected to the tube's socket or the tubes' plate resistor.

Even with what looks like a highly engineered regulated B+ supply, ( on the left side of the chassis ), there appears to be absolutely nothing storage wise, of high quality film capacitance at the tubes'-points-of-use !!

This circuit would sound better IF the designer provided an ideal amount of energy............. in each place, where it is used.

The AWG of B+ wiring, left to right, appears to be inadequate to support a wide band linear dynamic response. Thin B+ wiring and grounds will play music " from the top, on down", and not ever linearly "from the bottom up", and .....with " meat on the bone ".

PM me, and I will show you how to fix that. 14 AWG m22759/11 military wire wire is your friend. A partial solution. Keep the basic circuit, just improve the Manufacturer's execution.

Jeff

 

[RtoR King]

drlowmu,

I am not following you on this? Why would a tube preamp that uses a few milliamps of current need thicker wire than johnmicheal used? Hey, I'll try it myself but it doesn't make sense?

 

[drlowmu]

drlowmu,

I am not following you on this? Why would a tube preamp that uses a few milliamps of current need thicker wire than johnmicheal used? Hey, I'll try it myself but it doesn't make sense?

First of all, welcome to Hi Fi Visions Forum !!!

Your thought process seems logical, but in actual practice, it is faulty, if you seek the highest fidelity, in terms of definition and dynamics.

I have experienced this in my builds, over and over and over again, for at least 20 years of the last 40 years building tube circuits.

You may or may not be able to hear this in your builds, depending upon what other assumptions ( with possible errors ) exist in your executions.

( See the wiring in the DIY Forum's on-going SE DC 6005 thread, and notice precisely how I executed wiring. It is all very audible - at that build level. )

In this thread's preamp photo, do you see how there is absolutely NO local capacitance, no B+ storage on the audio boards, where the circuit is TRYING to play music. No, the regulated energy supply is six inches away, interconnected by P.U.ny wiring.

In my builds, film capacitors of high quality are only 1/8th of an inch from a triode's PLATE resistor, or 1/8th an inch the tube socket's pin.

What method would you think is superior for delivering instantaneous energy in pulsed play back of NON sinusoidal music wave forms. and events - six inches of thin wire or a quality film cap, located within 1/8th an inch of the use-point ?

I am referring to something like a pulsed drum solo with cymbals??

An even more interesting question, what do you THINK is the instantaneous PEAK current of a 12AX7 circuit idling at 1 mA??? The need for a great power supply, and wiring execution, with such low current tubes, is surprising.

I say these things to you, meaning absolutely no dis respect, but in an honest attempt to answer your question. " An inch of bad wire can ruin the musical experience. "

If you want to send me lotsa good below-deck photos, and a good schematic with voltages, I would be happy to suggest simple things for you to hear and try out. Private Mail me for my direct email address. I did this wire excercise with a high end USA audio Manufacturer, over the last two months. I would be glad to have you speak to him, on what he heard.

My suggestion would be to use Military Specified wire, m22759/11 specifically, readily available on eBay, etc., and at surplus prices. ( Apex Junior, Surplus Electronics, below ). I usually employ 16, 14 and 12 AWG as audio wire sizes, singles and paralleled combinations, depending upon circuit position. I am actually mailing some of this wire, those three AWGs, to Thane, Marharastra, in about an hour, from my home in the USA today !!

Jeff

 

[RtoR King]

But I still can't follow this idea. You say the preamp tube is limited to 1ma of plate current which most will agree. 8 inches of #24 wire can easily handle that minuscule amount of current. Where is all this high current coming from when the tube is limited by it's plate resistor to 1ma? If the tube is forced by the grid voltage and current to exceed the maximum current allowed through the tube, it will just clip. That's bad! But putting heavier wire to the plate resistor will not change the plate current set by the plate resistor, provided of course the original wire was of sufficient gauge and again 8 inched of #24 is more than enough.

I do agree there should be a bypass cap at the tube circuit power supply connection but heavier wire doesn't make any sense based.

I was a repair technician at a major shop for many years. We not only handled retail customers but also several large local HiFi stores who lacked a service shop. I have been inside many vintage tube gear and have never seen anything above #22 wire handling B+, especially in a preamp?

 

[bloredude]

The red and black twisted set of wires, from the volume control, to the white middle-of-the board inter-stage film caps, needs to be totally UNtwisted.

Isn't twisting said to reject RFI/EMI? Just curious what are the trade-offs?

 

[Hiten]

AWG and Peaks :
what is the estimated peak current demand for preamp or buffer ?
wouldn't rest of the chain, source/components/pcb tracks/fuses demand thicker gauge ?
If tubes are said to have safe operating conditions(currents/voltages) and if given high current for peaks through thick wires would'nt it shorten the life of tubes ?
thanks and regards

 

[drlowmu]

But I still can't follow this idea. You say the preamp tube is limited to 1ma of plate current which most will agree. 8 inches of #24 wire can easily handle that minuscule amount of current. Where is all this high current coming from when the tube is limited by it's plate resistor to 1ma? If the tube is forced by the grid voltage and current to exceed the maximum current allowed through the tube, it will just clip. That's bad! But putting heavier wire to the plate resistor will not change the plate current set by the plate resistor, provided of course the original wire was of sufficient gauge and again 8 inched of #24 is more than enough.

I do agree there should be a bypass cap at the tube circuit power supply connection but heavier wire doesn't make any sense based.

I was a repair technician at a major shop for many years. We not only handled retail customers but also several large local HiFi stores who lacked a service shop. I have been inside many vintage tube gear and have never seen anything above #22 wire handling B+, especially in a preamp?

22 AWG B+ wire in any amp or preamp which aspires to higher fidelity , is totally out of the question, compared to what I have found to work best. What more can I say ???

Did you view the wiring details of my 2021 6005 amp article, on this Forum, in the DIY section? Please do so .

New Design, SE 6005 Directly Coupled Audio Amplifier

This is a current design and build project, a DIY hobby of mine for many years. It uses a 6005 FINALS tube, which has a 10 Watt (correction - 12 Watt) plate dissipation, and was introduced in the 1950s. Used in car radios and TVs as the FINAL stage, in the USA and in Russia ( an equivalent )...

www.hifivision.com

The entire audio chain has to be wired properly. It is all very audible. I have been aware of this, in my builds, for over 40 years now.

AWG and Peaks :
what is the estimated peak current demand for preamp or buffer ?

We do not know, nor has it easily been measured. ( But I sure can easily hear it in my last few years' builds !!! )

wouldn't rest of the chain, source/components/pcb tracks/fuses demand thicker gauge ?

YES, the entire chain needs to be attended to, starting with the wire's from your residence's fuse panel, to your wall socket. Try to avoid PCB tracks, use real wire !! Good wire.

If tubes are said to have safe operating conditions(currents/voltages) and if given high current for peaks through thick wires would'nt it shorten the life of tubes ?

Not if the peaks are instantaneous, and not at all - in the manner I operate tube dissipations, which is very conservatively.

If you thoughtfully wire the entire system correctly, and apply great power supply design, you can obtain an fabulous level of dynamic definition, missing in 99.99 % of the tube audio equipment seen today. I achieved such a result, in a KT88 SE DC amp in 7-2019, my initial " big break through " success.

The 2021 6005 amp build will have this design. Have you viewed my 6005 SE DC amp article? (https://www.hifivision.com/threads/new-design-se-6005-directly-coupled-audio-amplifier.82963/). Take a careful look please sir. That amp , like the 2019 one, is designed for maximum dynamic definition and resolution, as a high priority.

See those two gray colored three inch round capacitors below deck in the 6005 amp? These caps lead to the Output tubes of my ( about ) 1.5 Watt / Channel stereo amp. Those caps are each rated at 1,200 Amperes peak instantaneous. Take them out of the L1/C1/L2/C2 filter to the output tube section, and the amp "dies" dynamically. I run my Output Tube, with a 12 Watt rated plate, at only 60 % of it's maximum rated dissipation, in loaf-mode.

Sounds better to me operating that way, less unbalanced DC on the core of the SE Output XFR, and less thermal stress upon the tube.

thanks and regards

I hope this is a bit clearer to you now. Study my 2021 6005 build.

Isn't twisting said to reject RFI/EMI? Just curious what are the trade-offs?

It intermodulates the wires' pulsed magnetic fields - between the left signal channel, and the right signal channel.

Trade - Offs ? I hear it as : it loses highs, purity, and dynamic contrasting. Sounds worse when input / music signal wires are twisted, or even touch just once for that matter, in any high end, well-implemented audio system.
Can not use tie wraps around such wires, or have any plastic materials touching the signal wires, it is a degrade. ( read Pierre Sprey, Mapleshade Audio, " Wire Management " section ).

 

[RtoR King]

22 AWG B+ wire in any amp or preamp which aspires to higher fidelity , is totally out of the question, compared to what I have found to work best.

What more can I say ???

Did you view the wiring details of my 2021 6005 amp article, on this Forum, in the DIY section? Please do so .

New Design, SE 6005 Directly Coupled Audio Amplifier

This is a current design and build project, a DIY hobby of mine for many years. It uses a 6005 FINALS tube, which has a 10 Watt (correction - 12 Watt) plate dissipation, and was introduced in the 1950s. Used in car radios and TVs as the FINAL stage, in the USA and in Russia ( an equivalent )...

www.hifivision.com

The entire audio chain has to be wired properly. It is all very audible. I have been aware of this, in my builds, for over 40 years now.

So you don't think the classic and coveted tube amps of the late 1950s and early 1960s were high fidelity? The Marantz 7, the entire McIntosh line, the Harmon Kardon Citation 2 & 5? These go for thousands on Ebay and not in pristine condition either.

I have repaired all of those and I can tell you the signal and high voltage circuits are wired with nothing bigger than #22awg. Of course the Filament buss can be #18 or #16 but that's it.

The 6AQ5/6005 is a slimmed down 6V6 that was designed for smaller TV sets. Probably 1-2 watts in SE mode. Not that it can't be a good audio tube but I think there are more suitable tubes unless of course you have a good stash of 6AQ5/6005s.

It intermodulates the wires' pulsed magnetic fields - between the left signal channel, and the right signal channel.

Trade - Offs ? I hear it as : it loses highs, purity, and dynamic contrasting.

Sounds worse when input / music signal wires are twisted, or even touch just once for that matter, in any high end, well-implemented audio system.
Can not use tie wraps around such wires, or have any plastic materials touching the signal wires, it is a degrade. (read Pierre Sprey, Mapleshade Audio, " Wire Management " section).

You mean "crosstalk"? I would not twist right and left channel signal wires together either. Bad idea as you point out. But using a twisted pair for a single channel where one wire is the hot and the other the return, twisting is a great idea in an audio product. Less capacitance than shielded cable yet still offers some noise rejection.

 

[drlowmu]

You mean "crosstalk"? I would not twist right and left channel signal wires together either. Bad idea as you point out. But using a twisted pair for a single channel where one wire is the hot and the other the return, twisting is a great idea in an audio product. Less capacitance than shielded cable yet still offers some noise rejection.

Look at the photo, the twisted wires I pointed out, are the left and right channel signal wires coming off the stereo volume control.

So you don't think the classic and coveted tube amps of the late 1950s and earl;y 1960s were high fidelity? The Marantz 7, the entire McIntosh line, the Harmon Kardon Citation 2 & 5? These go for thousands on Ebay and not in pristine condition either.

Those vintage amps do not impress me today as being the best possible implementation, as they can be easily bettered, performance-wise today IMHO.. I will let others chase them.

I have repaired all of those and I can tell you the signal and high voltage circuits are wired with nothing bigger than #22awg. Of course the Filament buss can be #18 or #16 but that's it.

I suggest, just because it was built that way, is no guarantee that it is ( or was ) the best way to do it !!! I hope we know better, at least some of us, in 2021.

The 6AQ5/6005 is a slimmed down 6V6 that was designed for smaller TV sets. Probably 1-2 watts in SE mode. Not that it can't be a good audio tube but I think there are more suitable tubes unless of course you have a good stash of 6AQ5/6005s.

I have a lot of experience with what is generally considered to be "the best" audio output tubes. My first amp build was a 2A3 P-P in about 1980. I would not choose an amp build because I have a stash of tubes !!

I would choose an output tube primarily because I think it is the best possible performer, as a linear performer into a speaker load. This is the main basis for me to select and design an amp...... using a 6005.

Design-wise, what has come before, what has been done before, has not much of a relationship, to 2021's 6005 design. No one, except me, has ever yet heard a 6005 amp.... as this will be implemented.

Kindly read that 16 point " laundry list " in the lower half of post #75 of that 6005 thread, and you can begin to see, what will be uniquely done :

New Design, SE 6005 Directly Coupled Audio Amplifier

OK, thank you so very much for the clarification !!! Please take some time, and study the Softone web site, as nicely detailed information on their audio output transformers is provided. They also offer an R-Core Interstage, that is likely very good. You might enjoy seeing all of that, if...

www.hifivision.com

Another way to appreciate the design, will be to listen to it play back music, once these 6005 amps are finished. ' Later this year.

Six copies will be made, for me and some friends.

Post #84 in the 6005 thread sums it up nicely, .... the aspirations :

" The 6005 tube amplifier, as designed here in this thread, is something I am most anxious to produce.

Why ?? I hear this 6005 tube itself, as being superior sonically; to almost all other audio output tubes (due to its symmetrical construction). Additionally, no one has ever applied such a circuit (shown earlier in this thread, see post #57) to an audio amplifier. This resulting amplifier, I actually already know, is going to be so much fun - to own and hear. The one minor downside - this project is taking much longer than I would have hoped it would."

 

[captrajesh]

I would choose an output tube primarily because I think it is the best possible performer, as a linear performer into a speaker load. This is the main basis for me to select and design an amp...... using a 6005.

Design-wise, what has come before, what has been done before, has not much of a relationship, to 2021's 6005 design. No one, except me, has ever yet heard a 6005 amp; as this will be implemented.

Kindly read that 16 point " laundry list " in the lower half of post #75 of that 6005 thread, and you can begin to see, what will be uniquely done :

Another way to appreciate the design, will be to listen to it play back music, once these 6005 amps are finished. ' Later this year.

Very interesting statements those.

Six copies will be made, for me and some friends.

Just thinking; there are quite a few members here on HFV who own high fidelity systems. It would be great if one of those can be passed around for us to experience this amp as well.

 

[drlowmu]

Very interesting statements those.

Just thinking; there are quite a few members here on HFV who own high fidelity systems. It would be great if one of those can be passed around for us to experience this amp as well.

Yes, actually, what two of us builders, ( myself and my Audio Mentor ) do with amplifier design is very interesting !! And unique.

No one will preview my amps, unless I supply the amp-to-speaker wiring, and oversee their system's total wire hook up.

Why don't you call upon long time FM, Hari Iyer, in Thane, and ask him to describe his own listening experiences with his 2020-built 6FQ7-KT88 DC SE monoblock amps. ( That way, I will not be the "sole voice in the wilderness" on HFV, ....crying out . )

I do not know how his amps compare to my own, but his amps have most of the things that my amps use. I 100% did his amplifiers' design, and guided his build very closely, in 2020.

Hari's two new DC SE KT88 amps replaced his 300B amp.

A few caveats : His execution is not precisely as I would do it, we are different people, with different experience, budgets, and speakers. Also, I have never heard his implementation.

Also, I know for a fact, his system is now in a state of flux. Hari recently installed new Softone R-Core output transformers - needing break in, ( which takes a long time ). But Hari is very smart, and honest enough to provide reliable verbal descriptions .........if he cares to, and if he has the time.

Now, I have to learn / see where Hyderabad is, in relationship to Mumbai / Thane. Google Maps. Hooray !! Fun.

Jeff

 

[Hari Iyer]

drlowmu,

I am not following you on this? Why would a tube preamp that uses a few milliamps of current need thicker wire than johnmicheal used? Hey, I'll try it myself but it doesn't make sense?

I recently discovered in my speakers wiring that using a 20 awg wire for full range driver internal wiring and using a 12 awg wire for the same has night and day difference.

With every thing same the thinner wire was too very much sweeter than I would have liked. I consider that as colouration. Using thicker wire removed the shine and made them sound accurate.

Popular wisdom is don't use wire as tone control. But that's what I have done. The wire type, gauge can be actual used to shape tone of your setup with everything else same

Isn't twisting said to reject RFI/EMI? Just curious what are the trade-offs?

Twisting also increases capacitance and bypass audio signal to ground

 

[drlowmu]

I recently discovered in my speakers wiring that using a 20 awg wire for full range driver internal wiring and using a 12 awg wire for the same has night and day difference.

With every thing same the thinner wire was too very much sweeter than I would have liked. I consider that as colouration. Using thicker wire removed the shine and made them sound accurate.

Popular wisdom is don't use wire as tone control. But that's what I have done. The wire type, gauge can be actual used to shape tone of your setup with everything else same

I find, we need to use a certain amount of wire, to effectively conduct the music information in a wide band and linear fashion. Not only is the wire gauge ( AWG ) important, but also, the wire's construction plays a large role, in perceived linear power transfer and in transfer efficiency.

Between amplifier and speaker, now-a-days, I find the approximate equivalent of about 8 AWG, seems to provide the best overall transfer efficiency. To retain bandwidth however, three different leads are typically used in parallel - to get this as an equivalent low value AWG.

Hari, you will hear such wire in a couple of weeks, a set of speaker leads were sent out this week, US International mail to Thane.

The speaker leads will need 50 -100 hours to break in. ' Be curious as to how it strikes you, listening - wise. Do report to us.

Jeff

 

[RtoR King]

Twisting also increases capacitance and bypass audio signal to ground

Yes is does. Shielded cable even worse. But single wire leads also act as antennas receiving hum and noise from within the device to external powerful local radio signals.

Everything in electronics, in fact any field of engineering, is a trade off. You must strive for an acceptable compromise because perfection can never truly be achieved.

Also there other ways to mitigate both cable capacitance and noise pickup. None of these solutions is perfect but you can get pretty close. This is why measurements and mathematics are so important in any field of electronics. There is nothing unique about audio in this regard.

As for your speaker wire report, this is a common criticism of commercial speakers construction. However with a basic understanding of basic DC circuits you will see the assumed fault is insignificant. It's not the wire gauge that matters. It's the total resistance of the circuit or wiring loop to the speaker and back. The resistance of a 10-20 foot run is significant. So yes, heavier gauge wire does reduce this resistance. But the length of the internal speaker wire is rather short, often under a foot. So the added resistance is minimal and thus the attenuation just as minimal.

Now does increasing the gauge of the internal speaker wiring lower the total resistance, yes it most certainly does. Even an inch of thin wire has more resistance than an inch of a thicker wire. But how much? Do the math then calculate the DB loss from the thinner inner wiring or the gain from thicker. You will probably in most cases find it's minuscule and well below the threshold of hearing.

Also consider the negative aspects of using thicker internal speaker wiring. Consider the mechanical problems attaching say a 12ga wire to a tiny tweeter driver terminal. The weight alone will be enough to eventually break the terminal off - and that will be quite audible!

 

[Hari Iyer]

I find, we need to use a certain amount of wire, to effectively conduct the music information in a wide band and linear fashion. Not only is the wire gauge ( AWG ) important, but also, the wire's construction plays a large role, in perceived linear power transfer and in transfer efficiency.

Between amplifier and speaker, now-a-days, I find the approximate equivalent of about 8 AWG, seems to provide the best overall transfer efficiency. To retain bandwidth however, three different leads are typically used in parallel - to get this as an equivalent low value AWG.

Hari, you will hear such wire in a couple of weeks, a set of speaker leads were sent out this week, US International mail to Thane.

The speaker leads will need 50 -100 hours to break in. ' Be curious as to how it strikes you, listening - wise. Do report to us.

Jeff

Sure Jeff, I am more than eager to check out this wires on my speaker.

Yes is does. Shielded cable even worse. But single wire leads also act as antennas receiving hum and noise from within the device to external powerful local radio signals.

Everything in electronics, in fact any field of engineering, is a trade off. You must strive for an acceptable compromise because perfection can never truly be achieved.

Also there other ways to mitigate both cable capacitance and noise pickup. None of these solutions is perfect but you can get pretty close. This is why measurements and mathematics are so important in any field of electronics. There is nothing unique about audio in this regard.

As for your speaker wire report, this is a common criticism of commercial speakers construction. However with a basic understanding of basic DC circuits you will see the assumed fault is insignificant. It's not the wire gauge that matters. It's the total resistance of the circuit or wiring loop to the speaker and back. The resistance of a 10-20 foot run is significant. So yes, heavier gauge wire does reduce this resistance. But the length of the internal speaker wire is rather short, often under a foot. So the added resistance is minimal and thus the attenuation just as minimal.

Now does increasing the gauge of the internal speaker wiring lower the total resistance, yes it most certainly does. Even an inch of thin wire has more resistance than an inch of a thicker wire. But how much? Do the math then calculate the DB loss from the thinner inner wiring or the gain from thicker. You will probably in most cases find it's minuscule and well below the threshold of hearing.

Also consider the negative aspects of using thicker internal speaker wiring. Consider the mechanical problems attaching say a 12ga wire to a tiny tweeter driver terminal. The weight alone will be enough to eventually break the terminal off - and that will be quite audible!

I have done an A-B atleast a 100+ times using a shielded, twisted and parallel running wires as interconnects. At least in my home and my setup I have noticed no hum, EMI or RF noise with a parallel wires as IC cables. Only occasional minimal noise I would hear is when I switch the fan regulator. So IME the noise issues solving due to twisting or shielded wire is over stated. I have noticed using super thin wire as IC cables prevents noise issues in parallel wires in IC cables.

For speaker wires - atleast for my speakers (full ranger) I have noticed vast difference between a 20 awg wire and 12 awg wire used within my crossover network. The wire was just 3" long and yet there was a huge impact. I did A-B on the 3" long wire to confirm and each time I could hear the difference. So how much resistance does a 20 awg 3" wire and a 12 awg 3" wire differ? Probably nil. But why do they sound so much different? I am not able to explain. The only explanation I have is transient response and transient current handling of the thicker wire is superior to thinner wires. We always look in terms of power, voltage and current and not in terms of transients. The thinner wires struggle in transient power delivery imo

 

[RtoR King]

I have done an A-B atleast a 100+ times using a shielded, twisted and parallel running wires as interconnects. At least in my home and my setup I have noticed no hum, EMI or RF noise with a parallel wires as IC cables. Only occasional minimal noise I would hear is when I switch the fan regulator. So IME the noise issues solving due to twisting or shielded wire is over stated. I have noticed using super thin wire as IC cables prevents noise issues in parallel wires in IC cables.

For speaker wires - atleast for my speakers (full ranger) I have noticed vast difference between a 20 awg wire and 12 awg wire used within my crossover network. The wire was just 3" long and yet there was a huge impact. I did A-B on the 3" long wire to confirm and each time I could hear the difference. So how much resistance does a 20 awg 3" wire and a 12 awg 3" wire differ? Probably nil. But why do they sound so much different? I am not able to explain. The only explanation I have is transient response and transient current handling of the thicker wire is superior to thinner wires. We always look in terms of power, voltage and current and not in terms of transients. The thinner wires struggle in transient power delivery imo

I am not surprised un-shielded interconnects worked well. In most residential situations there is little RFI energy in the audio band to be audible. So use straight wire interconnects if they work well for you. But in other environments shielded and twisted cable is necessary. Otherwise there would not numerous manufactures worldwide producing it.

Now on the crossover I have to ask if you did these tests blind? There are countless reports of minuscule wire changes in audio making "HUGE" differences. And they are always huge. Very rarely do we see a report that claims little to no difference. The problem here is clearly placebo effect. You expect a difference using what seem like a superior solution to a electronics novice, so you will hear one. Hence the need for DBT. Try the test with someone else making the changes to where you don't know which is which. You also need to make sure your test bed is properly controlled. Are you in the exact, I mean exact, same spot and head position when comparing the differences? Acoustics is very complex. Even a few inches of head movement can introduce audible changes to the ear.

BTW, why do you think a transient does not involve voltage and current? It most certainly does and the amount of each resulting in power can be captured and calculated.