My take at building audio grade power cord

I have been thinking about building a shielded power cord for my vintage stereo amps.without safety grounding.

For this effect, I will be using a two twisted 12 AWG (19 strands of 25AWG bare copper) conductors to create a low inductance/high capacitance configuration effective rejecting RFI/EMI, this should be a quantum leap ahead of the original zip lamp cord.

vjczua4t5sz7.jpg

The twisted conductors are shielded with a foil and a tinned copper braid, for maximum RFI rejection. The braid will be connected to the ground prong on the mains side, as follows:

i8texis0o0at.jpg



Comments

  • machone
    machone Posts: 1,471
    Make sure you use good plugs.
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  • drumminman
    drumminman Posts: 3,396
    Chris VenHaus has good stuff. I've made several of his cables, including Flavor 4's. Might want to consider unshielded ones if you don't have a huge RFI/EMI problem as they're supposed to sound better.

    Also, he has a recipe that involves an outer tube of rubber with a separate ground wire wrapped in a spiral opposite to the twist of the inner wires.
    "Science is suppose to explain observations not dismiss them as impossible" - Norm on AA; 2.3TL's w/sonicaps/mills/jantzen inductors, Gimpod's boards, Lg Solen SDA inductors, RD-0198's, MW's dynamatted, Armaflex speaker gaskets, H-nuts, brass spikes, Cardas CCGR BP's, upgraded IC Cable, Black Hole Damping Sheet strips, interior of cabinets sealed with Loctite Power Grab, AI-1 interface with 1000VA A-L transformer
  • mikeyb128
    mikeyb128 Posts: 2,885
    I believe I’ve read unshielded power cables have lower capacitance, which makes for a “faster more dynamic cable” therefore they sound better. Nordost power cables come to mind. In my experience I’ve heard heavily shielded power cables sound just as good as Unshielded ones.

    2 channel:
    Bryston 4B3, Bryston BDA3, Cary SLP05, Shanling CDT1000SE with parts conneXion level 2 mods, Nottingham analogue ace space 294, soundsmith Carmen MKii, Zu DL103 MKii, Ortofon MC 20 MKii, Dynavector XX2 MKii, Rogue Audio Ares, Core power technologies balanced power conditioner, Akiko Corelli power conditioner with Akiko Audio HQ power cable, Nordost heimdall 2, Frey 2, interconnects, speaker and power cables, Focal Electra 1028 BE 2, Auralic Aries Femto, Black diamond racing cones, ingress audio level 1 roller blocks, JL Audio E110 with Auralic subdude, Primacoustics room treatments.
    Theater:
    Focal Aria 926,905,CC900, SVS PB ultra x2. Pioneer Elite SC85, Oppo BDP93, Panamax M5400PM, Minix neox6, Nordost Blue heaven LS power cables.

  • verb
    verb Posts: 10,176
    Keep us posted @cortico ! Love DIYer's! :smile:
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  • machone
    machone Posts: 1,471
    Flavor 4

    f80u2y0zn0cd.jpg
    Mojo Audio Illuminati v3>>Quantum Byte w/LMS>>Rpi/PiCoreplayer>> Starlight 7 USB >> Mojo Audio Mystique v2 SE>>ModWright SWL 9.0 SE Signature>>Hafler DH-500 Amp+ (Musical Concepts Fully Modded)>>
    SRS 2.3TL (Fully Modded)...Velodyne Optimum 8 subwoofer
    1KVA Dreadnought

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    "All THAT IS LOST FROM THE SOURCE IS LOST FOREVER"
  • cortico
    cortico Posts: 587
    Thanks for your notes guys, the true is that I actual don’t have any issues with RFI/EMI noise, I may eleminate the shielding and focus on cable gauge, conductor quality and connections. I understand that the old power cord can negatively impact the power supply filtering rectified voltage charging cycles.
  • tonyb
    tonyb Posts: 32,902
    DSkip wrote: »
    cortico wrote: »
    Thanks for your notes guys, the true is that I actual don’t have any issues with RFI/EMI noise, I may eleminate the shielding and focus on cable gauge, conductor quality and connections. I understand that the old power cord can negatively impact the power supply filtering rectified voltage charging cycles.

    You don't know you do until its gone. I think everyone has an issue with it, just to what degree.

    Skip speaks the truth here. Noise isn't just represented in a hum or buzz that's obvious to the ear. I don't think, if it was me anyway, I'd forgo the shielding.
    HT SYSTEM-
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  • mikeyb128
    mikeyb128 Posts: 2,885
    DSkip wrote: »
    cortico wrote: »
    Thanks for your notes guys, the true is that I actual don’t have any issues with RFI/EMI noise, I may eleminate the shielding and focus on cable gauge, conductor quality and connections. I understand that the old power cord can negatively impact the power supply filtering rectified voltage charging cycles.

    You don't know you do until its gone. I think everyone has an issue with it, just to what degree.

    I was going to say the same. How do you know you don’t have RFI/EMI?
    2 channel:
    Bryston 4B3, Bryston BDA3, Cary SLP05, Shanling CDT1000SE with parts conneXion level 2 mods, Nottingham analogue ace space 294, soundsmith Carmen MKii, Zu DL103 MKii, Ortofon MC 20 MKii, Dynavector XX2 MKii, Rogue Audio Ares, Core power technologies balanced power conditioner, Akiko Corelli power conditioner with Akiko Audio HQ power cable, Nordost heimdall 2, Frey 2, interconnects, speaker and power cables, Focal Electra 1028 BE 2, Auralic Aries Femto, Black diamond racing cones, ingress audio level 1 roller blocks, JL Audio E110 with Auralic subdude, Primacoustics room treatments.
    Theater:
    Focal Aria 926,905,CC900, SVS PB ultra x2. Pioneer Elite SC85, Oppo BDP93, Panamax M5400PM, Minix neox6, Nordost Blue heaven LS power cables.

  • cortico
    cortico Posts: 587
    mikeyb128 wrote: »
    DSkip wrote: »
    cortico wrote: »
    Thanks for your notes guys, the true is that I actual don’t have any issues with RFI/EMI noise, I may eleminate the shielding and focus on cable gauge, conductor quality and connections. I understand that the old power cord can negatively impact the power supply filtering rectified voltage charging cycles.

    You don't know you do until its gone. I think everyone has an issue with it, just to what degree.

    I was going to say the same. How do you know you don’t have RFI/EMI?

    ^My setup isn’t revealing it. The background is pitch black, any present interferences are inaudible to me. The shielding would’t hurt, though!.. I’ll make 2 cables and AB it...
  • xschop
    xschop Posts: 4,636
    edited April 2018
    "My setup isn’t revealing it. The background is pitch black, any present interferences are inaudible to me. The shielding would’t hurt, though!.. I’ll make 2 cables and AB it... "

    I'll gladly take whichever one you don't use... ;)

    Don't take experimental gene therapies from known eugenicists.
  • delkal
    delkal Posts: 764

    If you do have RFI / EMI in your house electricity you are going to need more than a 3 foot power cord to get rid of it.

    Think of it this way. Your actual "power cord" goes from your breaker box to your system. You might have the last 3-6 feet of the best conductive cord available but it is still connected to 30-100 feet of 50 cents a foot 3 stranded Romex cable.

    Just because it is behind the wall doesn't mean it is not there.
  • pitdogg2
    pitdogg2 Posts: 24,478
    Think of it as the first 3-6 feet not the last
  • cortico
    cortico Posts: 587
    edited April 2018
    Ok, I made the first experiment using a 14AWG 3 prong contractor grade extension cord rated to 15amps 600v.

    The wire has 3 twisted stranded copper conductors and thick pvc insulation, I have cut a 4 foot section and saved the original 3 prong plug. Warped the entire cable length with 2 layers of conductive aluminum self adhesive tape which was connected to the ground conductor but isolated from the amp. At last, I applied a cable sleeve to improve the looks and cover the tape. It ended up not very flexible, I’m afraid aluminum tape won’t survive many bends, in the future I’ll use conductive braid...just a side note.

    Conclusion, I bumped gauge from 18 to 14, used better copper, twisted conductors, added shielding and used better connectors. My first impression is that the residual hiss when the volume is all the way up with no input signal is now null. I think I hear better channel separation too, does this make sense?!

    Edit: second impressions, I think this cable I built sucks! Jumped back and forth and stock 18awg cord seems to sound more lively with more clarity and better dynamics...

    I’m going back to the drawing board...

    7udtlll7ab6j.jpeg
    Post edited by cortico on
  • gp4jesus
    gp4jesus Posts: 1,969
    machone wrote: »
    Flavor 4

    f80u2y0zn0cd.jpg
    where to $ that IEC connector?
    Samsung 60" UN60ES6100 LED Outlaw Audio 976 Pre/Pro Samsung BDP, Amazon Firestick, Phillips CD Changer Canare 14 ga - LCR tweeters inside*; Ctr Ch outside BJC 10 ga - LCR mids, inside* & out 8 ga Powerline: LR woofers, inside* & out *soldered LR: Tri-amped RTi A7 w/Rotels. Woofers - 980BX; Tweets & “Plugged*” Mids - 981, connected w/MP Premiere ICs Ctr Ch: Rotel RB981 -> Bi-amped CSi A6 Surrounds: Premiere ICs ->Rotel 981 -> AR 12 ga -> RTi A3. 5 Subs: Sunfire True SW Signature -> LFE & Ctr Ch; 4 Audio Pro Evidence @ the “Corners”. Power Conditioning & Distribution: 4 dedicated 20A feeds; APC H15; 5 Furman Miniport 20s *Xschop's handy work
  • machone
    machone Posts: 1,471
    Furutech FI-11 CU @ Douglasconnection.com
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    Separate subpanel with four dedicated 20 amp circuits.
    1. Amplification 2. Analog 3. Digital 4. Video

    "All THAT IS LOST FROM THE SOURCE IS LOST FOREVER"
  • cortico
    cortico Posts: 587
    I am perplex as I though I would never hear any differences with my lousy diy cords and low end gear.

    I can definitely see a pattern that are probably related with the capacitance and inductance of the different schemes:

    -18 vs 14 gauges,
    (thicker wire benifted low end and soundstage width, slightly tamed upper freqs)

    -shielded vs unshielded,
    (Shielding muted dynamics, more defenition but mid range seamed setback in the mix)

    -parallel vs twisted conductors,
    (there’s tone changes, specially high end)

    -with exterior insulation vs wihout exterior insulation, (good dynamics and clarity without cable rubber jacket)

    These results are related to my specific gear and hears therefore subjective. Changes are not subtle, most tone differences can be compensated with tone controls but the sound stage dimension, focus and dynamics are a hit or miss situation.

    Ok, enough of nonsense:)


  • cortico
    cortico Posts: 587
    edited April 2018
    FWIW, I have found a run of Romex 12awg wire on the trunk of my father in law’s car, who’s an electrician by trade and decided to give it a try. The cable has 3 solid copper conductors runing in paralel inside a vinyl sleeve. It’s my favorite so far, imparts all the qualities of the previous thicker wires and apparently without noticeable losses I noticed with other schemes... the system sounds bigger!

    1hwa2yy8m4p0.jpeg
  • Clipdat
    Clipdat Posts: 12,560
    Interesting observations! Looks like AA sells a snobby Cardas version of it here for $16.26/foot!

    http://www.audioadvisor.com/prodinfo.asp?number=CRIW3X10

    CRIW3X10_D1.jpg
    cortico wrote: »
    FWIW, I have found a run of Romex 12awg wire on the trunk of my father in law’s car, who’s an electrician by trade and decided to give it a try. The cable has 3 solid copper conductors runing in paralel inside a vinyl sleeve. It’s my favorite so far, imparts all the qualities of the previous thicker wires and apparently without noticeable losses I noticed with other schemes... the system sounds bigger!

  • gp4jesus
    gp4jesus Posts: 1,969
    edited April 2018
    cortico wrote: »
    18 vs 14 gauges, thicker wire benefits low end...
    interesting...

    Assuming 4 amps, 18 ga versus 14 ga nets a voltage drop reduction of a mere .04 volts. Yet some perport upgrading to 10 or 12 from 14 or 16 isn’t worth it.

    Go figure...
    Samsung 60" UN60ES6100 LED Outlaw Audio 976 Pre/Pro Samsung BDP, Amazon Firestick, Phillips CD Changer Canare 14 ga - LCR tweeters inside*; Ctr Ch outside BJC 10 ga - LCR mids, inside* & out 8 ga Powerline: LR woofers, inside* & out *soldered LR: Tri-amped RTi A7 w/Rotels. Woofers - 980BX; Tweets & “Plugged*” Mids - 981, connected w/MP Premiere ICs Ctr Ch: Rotel RB981 -> Bi-amped CSi A6 Surrounds: Premiere ICs ->Rotel 981 -> AR 12 ga -> RTi A3. 5 Subs: Sunfire True SW Signature -> LFE & Ctr Ch; 4 Audio Pro Evidence @ the “Corners”. Power Conditioning & Distribution: 4 dedicated 20A feeds; APC H15; 5 Furman Miniport 20s *Xschop's handy work
  • delkal
    delkal Posts: 764
    According to this article solid core wires (romex et al) make excellent power cords. Unfortunately you will never find one since solid core wires are not UL approved for power cables. You have to make your own.

    From the article.


    The reality is that a power cord made from 12-14 gauge solid copper is pretty good. The problem with this is that this wire is not UL approved for cords and is very inflexible indeed. Most electrical Romex runs to the outlet in question are 20-40 feet in length. The power cord adds an additional 6 feet or so, so this is a small percentage of the entire run. It turns out that typical "rubber" stranded copper power cords have significantly higher inductance than the Romex in the wall, even at the same wire gauge, so these are not recommended. Empirically, stranded rubber cords have been demonstrated to limit transient high-power currents (dynamics) compared to solid copper conductors when supplying power to typical audio power amplifiers.

    It is fairly easy to build a serviceable cable that will minimize power cord inductance. A simple 3-conductor twisted cable from 12 AWG solid THHN from Home Depot yields a very high quality power cord, although it is so stiff that it must be bent to the desired shape. It is actually superior to the Romex in the wall because the twisting and close proximity of the insulated conductors will reduce the inductance by magnetic coupling between the conductors. In the optimum configuration, the Hot and Neutral are twisted together and then the ground wire run beside or wrapped around them.


    empiricalaudio.com/computer-audio/technical-papers/myths-and-snake-oil
  • cortico
    cortico Posts: 587
    Good article, thanks for sharing!
  • miner
    miner Posts: 1,305
    machone wrote: »
    Flavor 4

    f80u2y0zn0cd.jpg

    That is one vintage ZZ Top picture there machine.
    [
  • machone
    machone Posts: 1,471
    Macon, GA in 74ish.
    Mojo Audio Illuminati v3>>Quantum Byte w/LMS>>Rpi/PiCoreplayer>> Starlight 7 USB >> Mojo Audio Mystique v2 SE>>ModWright SWL 9.0 SE Signature>>Hafler DH-500 Amp+ (Musical Concepts Fully Modded)>>
    SRS 2.3TL (Fully Modded)...Velodyne Optimum 8 subwoofer
    1KVA Dreadnought

    Marantz SA 8005
    Pioneer PLX-1000 Turntable - Shure SC35C/N35X - V15III/VN35HE
    Yamaha TX-540 Tuner...Sony BDP-S570
    Sony PS4

    Separate subpanel with four dedicated 20 amp circuits.
    1. Amplification 2. Analog 3. Digital 4. Video

    "All THAT IS LOST FROM THE SOURCE IS LOST FOREVER"
  • gp4jesus
    gp4jesus Posts: 1,969
    edited April 2018
    Great article and...

    Oops...
    gp4jesus wrote: »
    cortico wrote: »
    18 vs 14 gauges, thicker wire benefits low end...
    interesting...

    Assuming 4 amps, 18 ga versus 14 ga nets a voltage drop reduction of a mere .04 volts. Yet some perport upgrading to 10 or 12 from 14 or 16 isn’t worth it.

    Go figure...
    “Yet some perport upgrading speaker wire from 14 or 16 to 10 or 12 gauge isn’t worth it.”

    I can’t figure..

    Samsung 60" UN60ES6100 LED Outlaw Audio 976 Pre/Pro Samsung BDP, Amazon Firestick, Phillips CD Changer Canare 14 ga - LCR tweeters inside*; Ctr Ch outside BJC 10 ga - LCR mids, inside* & out 8 ga Powerline: LR woofers, inside* & out *soldered LR: Tri-amped RTi A7 w/Rotels. Woofers - 980BX; Tweets & “Plugged*” Mids - 981, connected w/MP Premiere ICs Ctr Ch: Rotel RB981 -> Bi-amped CSi A6 Surrounds: Premiere ICs ->Rotel 981 -> AR 12 ga -> RTi A3. 5 Subs: Sunfire True SW Signature -> LFE & Ctr Ch; 4 Audio Pro Evidence @ the “Corners”. Power Conditioning & Distribution: 4 dedicated 20A feeds; APC H15; 5 Furman Miniport 20s *Xschop's handy work