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August 8, 2011

Custom Right Angle Double Shielded IEC Power Cord

So you may notice from the abundance of power cords on DIYAudioBlog that I enjoy making them ;) I find that they're both cost effective and higher quality compared to many audiophile-marketed power cords. Also, if you're bitten by the DIY bug, you tend to enjoy building everything you can on your own. In this post, I'll be assembling a relatively short 3 foot right angle double-shielded IEC power cord. This will be my first double shielded power cord, making use of both a tinned copper mesh braid and a full coverage EMI / RFI blocking 3M aluminum tape shield.

What's unusual is many of the handmade audiophile power cables don't use a shield at all; it's typical to see a cable with three 10 gauge conductors in a spiral within a big thick PVC jacket, but no shielding when it could be easily incorporated. Because these power cords are huge and make use of big conductors, they have a ton of capacitance, which offers EMI / RFI a great opportunity to rear its ugly head. Companies like PS Audio offer shields on their cords; their pricier models offering as many as four shields. It's hard to say if adding shield after shield is beneficial having never tested past 2, perhaps it can be the subject of a future post.

This cord will making use of a right-angle hospital-grade Marinco 3 prong plug. This is achieved by purchasing the typical Marinco 8215 plug (~$9) and the Wattgate WG15RA (~$15) right-angle adapter piece and combining the two. The right-angle adapter can be oriented in eight different positions depending on what angle you'd like the wire leaving the outlet.

The Wattgate WG15RA
The cable starts like the other power cables I've built. I trimmed three 10 gauge SPC in Teflon conductors and twisted them together in a spiral by hand.

Spiral of three 10 gauge SPC in Teflon conductors

These conductors are then wrapped in PTFE (Teflon) tape. Rather than using the thin 1/2" plumbers tape that I've used in the past, I opted to source some thicker 1" PTFE tape to trim down the time on the wrapping process, as the cable gets wrapped a total of four times, it can take a while.

Initial two layers of 1" PTFE Tape

Once the teflon is wrapped around the three conductors, a layer of 3M EMI / RFI blocking 3M aluminum tape is wrapped around the cable. This is a full coverage shield, none of the cable underneath is visible once wrapped, and there is a decent amount of overlap.

3M EMI / RFI blocking tape layer (first shield)

After the foil shield is laid down, the tinned copper braid mesh is run over top of it, then a buss wire is wrapped around the shield and soldered at the source side. This acts as a drain wire and connects the shield conductivity to the ground at the power source.  

Tinned copper mesh shield layer (second shield)

Now, the two final layers of PTFE tape are wrapped around the cable. 

Final two layers of 1" PTFE tape

Then comes a layer of attractive nylon multifilament copper sleeving to cover up the bland looking PTFE tape, followed by black heatshrink at each end. The Marinco 3 prong connectors are screwed on each side, with enough force to keep them in place but not enough to strip the screws within. Here's a photo of the finished product:

The finished two shield 10 gauge power cable
Power and beauty in one! ;)

The Fine Print:
The above steps detailing the creation of a power cord are for entertainment purposes only, and not to be performed under any circumstances. Please remember that attempting to use homemade power cords can be dangerous to you and/or your surroundings. The owner of this blog and all associated parties can not / will not be held responsible if you attempt the process posted below and cause physical harm to yourself or your surroundings. Many electronics contain high voltages that can kill, and DIY power cables can be a fire hazard. Please keep this in mind.


  1. Hi, where did you get your copper mesh from.

  2. Hi Lars, Partsconnexion and Percy Audio both carry it.