Fulton AC Power Cable - DIY

[HappyBear]

DIY Fulton AC power cable by Happy Bear to be used with the Manifesto SE amplifier.

10/3 SOOW 600V unshielded stranded copper wire was cut to a Fulton length of 57 1/8".

IEC connectors were cryo-treated Wattgate 320i and 5266i.

While the cable is mechanically and electrically sound, a professional look and haptic was unrealized without a nice-looking jacket.

The cable ends were crudely finished with some black electrical tape.

HB will revisit this aspect of the DIY cable project to see if cosmetic improvements can be achieved.

 

[HappyBear]

A second Fulton length cable of 114 1/4" was cut and connected to a Daniel Woodhead industrial-grade AC distribution box.

The Fulton cable was terminated with a Legrand 5266X NEMA 5-15P male IEC plug.

Laptop and DAC power supplies plug into the distribution box which is connected to an old Monster Power line conditioner.

The industrial parts lack in audiophile aesthetics but function with appropriate subjective attributes during listening sessions.

HappyBear

 

[HappyBear]

Adding surge protection to power strip by HappyBear.

HB removed the circuit board from an old Monster Power HT700 AC line conditioner and harvested 9 pcs. of MOV (metal oxide varistor).

The varistors and a 120V indicator lamp were installed into a male IEC plug with screw terminals.

This varistor module gets plugged into the first socket on the power strip after the switch and 15A breaker.

When the amplifier has a filtered IEC inlet, as in the case of the Manifesto SE tube amplifier, there is not much need for additional filtering on the AC line.

This concept with be refined with a better enclosure, electrical sockets and Fulton wiring, etc. if the subjective review is favorable.

 

[Hari Iyer]

I am using Fulton lengths DIY power cables for my tube amplifiers. These were made with 3 x 571/8 inches 12 awg mill spec silver plated copper wire with Teflon jacket. The line and neutral are slightly twisted. On top of that a 8 mm cotton rope was wound and the earth wire was lightly twisted on top of this to reduce capacitance. I am using this past 3+ years and am not looking back.

 

[HappyBear]

I am using Fulton lengths DIY power cables for my tube amplifiers. These were made with 3 x 571/8 inches 12 awg mill spec silver plated copper wire with Teflon jacket. The line and neutral are slightly twisted. On top of that a 8 mm cotton rope was wound and the earth wire was lightly twisted on top of this to reduce capacitance. I am using this past 3+ years and am not looking back.

HB used the same wire for Fulton length speaker cables 114.25" a few years ago. Single runs to woofer +/- polarities.

 

[HappyBear]

Power cable management/strain relief by HB.

Fulton power cables from Manifesto SE amp and Woodhead distribution box now directly plugged into duplex wall outlet with assistance of clamps which are screwed down on the cabinet.

The contacts in the old duplex wall outlet seem a bit loose, so it is perhaps time to upgrade those with a new outlet.

In my area, we have Legrand, Eaton and Leviton brands available - mostly residential or commercial products.

 

[HappyBear]

Woodhead AC distribution box and AC power strip upgrades by HappyBear.

A Pass & Seymour CRB5262 15A commercial grade duplex outlet was installed in the Woodhead box. The original outlets had been exposed to harsh conditions in the garage for many years and had some external corrosion on the mounting strap. Better to be ensure the best contact integrity by installing new outlets.

The power strip male IEC connector was upgraded to a Oyaide copy. The duplex outlets were a decent Leviton brand, so they were just cleaned with DeoxIT D5 contact cleaner and kept in place.

The remaining upgrade with be to replace the ancient wall outlet with a new P&S CRB5262 duplex outlet.

 

[HappyBear]

New duplex outlet installed by HappyBear.

P&S 5262 15A duplex outlet installed tonight.

This duplex outlet was recommended by Jon Risch as a "good for audio" value-minded component.

The old outlet was a Leviton, US made circa early 1960's.

Simple but effective upgrades: 10AWG stranded copper wire in Fulton lengths, new IEC connectors and duplex outlets.

 

[FlaCharlie]

10/3 SOOW 600V unshielded stranded copper wire was cut to a Fulton length of 57 1/8".

HB used the same wire for Fulton length speaker cables 114.25" a few years ago.

I'm having a hard time understanding why such a precise length of 57 1/8" between the amp and wall socket would be important for a power cable considering that you have no control over the distance between the wall socket and the transformer mounted on the power pole outside.

If you think there is a magic length for a speaker cable you at least have some control over that, but this is not the case with a power cable. The distance will even be different when measured from different rooms in your house or even different outlets in the same room.

For the speaker cables, do you include the wire inside the speaker cabinet between the connector and the driver? And if used with a tube amp to you also include the length of the wire from the output transformer to the speaker jacks? Both of those will vary between different speakers and different amps.

 

[HappyBear]

I'm having a hard time understanding why such a precise length of 57 1/8" between the amp and wall socket would be important for a power cable considering that you have no control over the distance between the wall socket and the transformer mounted on the power pole outside.

First, control what can be controlled.

The quality of AC power cable from wall outlet to amplifier can be manipulated for a positive subjective effect, in HB's experience.

Fulton lengths are only one part of the quality equation along with wire composition, wire AWG and termination.

Direct experience by experimentation will lead to understanding.

HB

 

[Hari Iyer]

Fulton lengths are thought to be less reflective and allow full transfer of power from source to destination. If you divide 180 by PI you get Fulton length.

 

[FlaCharlie]

First, control what can be controlled.

The quality of AC power cable from wall outlet to amplifier can be manipulated for a positive subjective effect, in HB's experience.

Fulton lengths are only one part of the quality equation along with wire composition, wire AWG and termination.

Direct experience by experimentation will lead to understanding.

HB

That's exactly my point. You have no control over the total length between the power pole and your amp. And it's different for every socket in your house. If you think cable length matters you can't just ignore the wire between the wall socket and the power pole, even if you can't control it.

The length from wall socket to amp is just a tiny % of the total length of wire between the transformer on the power pole and the wall socket. Given that, the notion that it should be any particular length, "Fulton" or otherwise, seems a bit ridiculous. And the idea that the length should be specified down to 1/8" (3.175 mm) is even more absurd.

Even if you believe that such an exact length matters, if you switch amps the length of wire between the other side of the IEC and the power transformer primary winding is likely also slightly different. So in order to adhere to the prescribed length you would need to build all of your amps with exactly the same length of transformer primary lead and include that in the total length of the cable. Otherwise your precise measurement will not be accurate and will vary when different amps are used with the same IEC cable.

As for the wire itself, depending on how far your house is from the pole, much of the wire is whatever the electric company uses between the pole and the house. I suppose they could tell you what they use but I can't imagine that anyone would consider it "audiophile approved". Its AWG certainly should be sufficient, however, since it must supply the current needs of the whole house.

Then within the walls of your house the wire is typically just common copper Romex. Whatever AWG it is it's obviously sufficient to supply the maximum current that the breaker in your breaker box is rated for, typically 15A. So using a larger AWG between the Romex and the amp doesn't increase the current capability of the existing circuit, even if the thicker wire can technically handle more current. Stereo gear doesn't draw that much current anyway. A small electric space heater or a vacuum cleaner will draw many times more current.

Certainly having a good solid connection matters. And in some situations so might shielding.

You didn't comment on the speaker cable length, which is something you can control.

I'm curious if you include the length of the output transformer secondary wire and connector on the back of the amp as well as the wire between the connector on the speaker and the driver? Or do you ignore that too? Again, if you use different speakers you would end up with different lengths unless they all have the same length of wire internally.

Seems to me that normalizing all this down to the millimeter would be a tall order if you use multiple amp and speaker combinations. I suspect that most who have built speaker cables using the Fulton formula have built the cable itself to the prescribed length but ignored the wiring inside the amp and the speaker cabinet. Unless you included those have you really built a proper Fulton speaker cable? As for power cables, the task seems to be so impractical that it's essentially impossible.

But, hey, it's DIY where we all build things for our own enjoyment so there's nothing wrong with experimenting with all kinds of things, including cable length.

 

[HappyBear]

57 1/8" Fulton power cable (Monster Power Line 100 14/3) with Oyaide copy IEC terminations.

Chinese-made AC power strip modified with filtered IEC inlet and Pass & Seymour 5262 duplex outlets.

All AC power cables are now Fulton lengths from wall outlet to distribution box to power strip.

Eventually, another power strip and cable will be constructed with 10/3 AWG wires for better transfer efficiency.

The small form factor of the Chinese power strip was a limiting factor in terms of wiring.

HappyBear

 

[FlaCharlie]

Fulton lengths are thought to be less reflective and allow full transfer of power from source to destination. If you divide 180 by PI you get Fulton length.

I'm aware of the theory. My questions involve the implementation.

I was hoping that @HappyBear would comment on the Fulton speaker cable length? Unlike the power cable, its length can easily be controlled.

If we accept the premise that an exact, prescribed length of speaker cable is desirable, it seems to me that it's the "electrical length" that matters. The "electrical length" is the distance between the actual electrical components, such as the secondary winding of the output transformer and the speaker driver, not the distance between the speaker jacks on the amp chassis that the OT is mounted on and speaker jacks on the cabinet that the speaker driver is mounted in.

The "electrical length" includes not only the cable between the amp and the speaker cabinet, it also includes the length of the wire lead between the OT secondary and the amp's speaker jacks as well as the length of wire inside the speaker cabinet between the speaker jacks and the driver.

Those lengths vary and if you ignore them it makes no sense to be so exact (down to 1/8" or 3.175mm) when making a speaker cable.

Let's say there is 3" of wire inside the amp chassis between the OT secondary winding and the amp's speaker jacks and then, on the other end, there is 8.5" of wire inside the speaker cabinet between the speaker jacks and the driver. The result is that the "electrical length" is 11.5" longer than a speaker cable built to the prescribed 57.125" length.

The total "electrical length" is now 68.625" which does not conform to the Fulton formula. It's now 20% longer than it should be. That's a huge difference when you consider that the length supposedly needs to be controlled down to 1/8" in order to be optimal.

And the additional wire will vary from amp to amp and speaker to speaker. The end result is that the "electrical length" becomes random, not controlled, so it doesn't actually conform to any formula for prescribed length, "Fulton" or otherwise.

 

[Hari Iyer]

Y

I'm aware of the theory. My questions involve the implementation.

I was hoping that @HappyBear would comment on the Fulton speaker cable length? Unlike the power cable, its length can easily be controlled.

If we accept the premise that an exact, prescribed length of speaker cable is desirable, it seems to me that it's the "electrical length" that matters. The "electrical length" is the distance between the actual electrical components, such as the secondary winding of the output transformer and the speaker driver, not the distance between the speaker jacks on the amp chassis that the OT is mounted on and speaker jacks on the cabinet that the speaker driver is mounted in.

The "electrical length" includes not only the cable between the amp and the speaker cabinet, it also includes the length of the wire lead between the OT secondary and the amp's speaker jacks as well as the length of wire inside the speaker cabinet between the speaker jacks and the driver.

Those lengths vary and if you ignore them it makes no sense to be so exact (down to 1/8" or 3.175mm) when making a speaker cable.

Let's say there is 3" of wire inside the amp chassis between the OT secondary winding and the amp's speaker jacks and then, on the other end, there is 8.5" of wire inside the speaker cabinet between the speaker jacks and the driver. The result is that the "electrical length" is 11.5" longer than a speaker cable built to the prescribed 57.125" length.

The total "electrical length" is now 68.625" which does not conform to the Fulton formula. It's now 20% longer than it should be. That's a huge difference when you consider that the length supposedly needs to be controlled down to 1/8" in order to be optimal.

And the additional wire will vary from amp to amp and speaker to speaker. The end result is that the "electrical length" becomes random, not controlled, so it doesn't actually conform to any formula for prescribed length, "Fulton" or otherwise.

Fulton lengths are node to node calculated at the terminations where there can be some mis-match happening due to various factors and contact resistance.

 

[HappyBear]

That's exactly my point.

Without practical application, the engineering approach is incomplete.

The "cut and try" will prove to be more enlightening since building a DIY power cable is a fairly simple activity.

There is a YT video by Danny Ritchie of GR Research where he goes into some detail about the subjective differences caused by different AC power cables.

Nothing was mentioned about Fulton lengths, but it does provide some rationale for experimenting and listening.

HB

 

[FlaCharlie]

Without practical application, the engineering approach is incomplete. The "cut and try" will prove to be more enlightening . . . it does provide some rationale for experimenting and listening.

I was hoping that @HappyBear would comment on the Fulton speaker cable length? Unlike the power cable, its length can easily be controlled.

Fulton lengths are node to node calculated at the terminations

Well I'm all for experimenting and listening and I'm certainly not an engineer. I don't even own a scope so I suspect that you rely on measurements more than I do. If I relied on engineering and measurements I wouldn't need to spend 9+ months breadboarding and listening before building an amp.

But my comments are not related to procedure, they're related to characteristics of a "Fulton" cable.

The distinguishing characteristic of a "Fulton" cable is its precise, prescribed length or multiples of that length. Other characteristics of the cable might vary and be important, but unless the prescribed length is used it's not considered to be a "Fulton cable".

What Hari is saying - and what you have avoided commenting on - is that the length between the terminations should be measured down to the millimeter but that the total "electrical length" is not an important consideration.

For a speaker cable, the components that are actually "doing the work" are the amplifier's output transformer and driver inside the speaker cabinet.

A "Fulton length" speaker cable, when measured between the terminations as Hari suggests, only constitutes the middle portion of the total "electrical distance" between those key components.

So apparently any additional wire added to either end, regardless of length, is not important?

I guess I don't understand the logic behind this.

Interestingly, the same individual who often mentioned (past tense since he's been banned on every forum he's ever joined including this one) Robert Fulton as a mentor and promoted the notion of "Fulton length" cables also supports the idea that every inch of wire counts.

In this case there would seem to be a conflict between those two positions if the total "electrical distance" between the key components can be ignored while the middle portion must be measured with great precision.

Of course, some time back on another forum he also promoted the notion that wire with black insulation degrades the sound and should be avoided at all cost. That's always been one of my favorites!

[Jeff, if you still follow this forum I hope you're doing well! You really should start your own YouTube channel, which is something I've suggested before. Easy enough to make and post a video with your phone. Unless you're like me and still use a landline. I bet it would be a great success and if you could attract enough subscribers it could even help fund your builds. No worries about being banned either! If that doesn't appeal to you I'm sure there are other forums but you'll need to learn some new languages. I think you've probably eliminated all the ones that post in English.]

 

[HappyBear]

Well I'm all for experimenting and listening and I'm certainly not an engineer. I don't even own a scope so I suspect that you rely on measurements more than I do. If I relied on engineering and measurements I wouldn't need to spend 9+ months breadboarding and listening before building an amp.

But my comments are not related to procedure, they're related to characteristics of a "Fulton" cable.

The distinguishing characteristic of a "Fulton" cable is its precise, prescribed length or multiples of that length. Other characteristics of the cable might vary and be important, but unless the prescribed length is used it's not considered to be a "Fulton cable".

What Hari is saying - and what you have avoided commenting on - is that the length between the terminations should be measured down to the millimeter but that the total "electrical length" is not an important consideration.

For a speaker cable, the components that are actually "doing the work" are the amplifier's output transformer and driver inside the speaker cabinet.

A "Fulton length" speaker cable, when measured between the terminations as Hari suggests, only constitutes the middle portion of the total "electrical distance" between those key components.

So apparently any additional wire added to either end, regardless of length, is not important?

I guess I don't understand the logic behind this.

Interestingly, the same individual who often mentioned (past tense since he's been banned on every forum he's ever joined including this one) Robert Fulton as a mentor and promoted the notion of "Fulton length" cables also supports the idea that every inch of wire counts.

In this case there would seem to be a conflict between those two positions if the total "electrical distance" between the key components can be ignored while the middle portion must be measured with great precision.

Of course, some time back on another forum he also promoted the notion that wire with black insulation degrades the sound and should be avoided at all cost. That's always been one of my favorites!

[Jeff, if you still follow this forum I hope you're doing well! You really should start your own YouTube channel, which is something I've suggested before. Easy enough to make and post a video with your phone. Unless you're like me and still use a landline. I bet it would be a great success and if you could attract enough subscribers it could even help fund your builds. No worries about being banned either! If that doesn't appeal to you I'm sure there are other forums but you'll need to learn some new languages. I think you've probably eliminated all the ones that post in English.]

The Fulton length of 57 1/8" or multiples was measured from end to end of the wire, terminations are not included in the power cables HB has assembled and presented here on HFV.

Audio system cables fall to the realm of "black arts" and there are too many types of wire, jacketing and terminations to know if there will be positive synergy with any particular combination. That is where "cut and try" alchemy becomes needed to gain the knowledge.

Don't suffer from "analysis paralysis", this is a simple process. Build a Fulton length cable and listen to it.

HappyBear