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DIY mil-spec DC umbilical

76.104.217.128

Image: Apple iMac computer, Lifatec Silflex Glass Toslink cables, active digital optical Toslink splitter/repeater, set-screw termination type 2.1 DC power connector, 16 AWG Mil-Spec SPC/PTFE Teflon twisted pair, multipole 2-pin connector, 5VDC linear power supply unit.

Even the most humble audiophile devices can benefit via PSU upgrades. In this case, I'm in the process of building a DIY mil-spec DC umbilical for an inexpensive linear power supply upgrade for an inexpensive high-quality active digital optical splitter/repeater in order to route a digital optical cable from an Apple iMac to both my computer workstation audio system located within an alcove of my listening room, and the main audio system located across the room.

The Toslink splitter/repeater was satisfactory when the stock 5VDC switch mode wall wart was upgraded with a regulated linear wall wart, but I considered it possible that a more ideal linear power supply unit upgrade might perform considerably better than a mundane wall wart, even for a humble Toslink splitter/repeater device. In short, after a few hundred hours of break-in, a lower-cost level audiophile linear power supply unit sourced from eBay took the Toslink splitter/repeater to a higher performance level than before. Most notably, a more palpable presence (out of the box, and into the room) without sounding too forward after break-in, increased perception of percussive dynamics, and more authoritative bass weight among other improvements.

At this point, I've ordered the mentioned parts in order to build a DIY 16 AWG Mil-Spec SPC/PTFE Teflon twisted pair DC umbilical to replace the mundane detachable stock 18 AWG PVC DC umbilical featuring an unnecessary ferrite core at the load end. I plan to post a report sometime down the road.

Note: Each Toslink output cable is plugged into a Monarchy Audio DIP placed in each audio system, with a digital coaxial interface with each DAC. Otherwise, satisfactory use of the Toslink interface method was impossible to achieve from an audiophile perspective, IME.

Cheers, Duster

Follow Ups:

RE: DIY mil-spec DC umbilical - beppe61 23:02:00 04/21/15 (1)
Hi and thanks a lot for disclosing this very interesting project.
But i have a question.
Why not use for the umbilical a very good coaxial with the center conductor for + and screen for - ?
Regarding the plug with a coaxial maybe a soldered one could be better.
Thanks again.
Kind regards,
bg
- Teflon tape wrapped. - Duster 16:14:19 04/22/15 (0)
  Special Note: I recommend the twisted pair be wrapped with a couple of layers of Teflon plumbers tape for better performance of the DC umbilical. The assembly should then be covered with Techflex braided sleeving.
  
  A simple twisted pair is ideal for a DIY DC umbilical project. Specifically, Mil-Spec silver plated copper, PTFE Teflon insulated wire is an excellent type of wire to implement for for an audiophile quality DC umbilical. While I find the sonic signature of Mil-Spec wire to be unsatisfactory for AC applications, it sounds great for DC applications. The performance level of a mil-spec DC umbilical upgrade can be equivalent to an interconnect cable upgrade due to better clarity vs. an ordinary stock PVC DC umbilical. It can also be considered equivalent to an audiophile power cord upgrade vs. a stock PVC power cord.
  
  Shielded twisted pair mil-spec DC umbilicals are also excellent, but can be a bit more difficult to terminate vs. a simple twisted pair.
I'm looking forward to your report - 1973shovel 05:27:47 04/21/15 (15)
I'd never seen that type of DC female plug before I noticed them in your post. You didn't say what they were, but I eventually found out they are CCTV DC plugs. The external screw terminals seem to allow the use of heavier gauge wire than the typical internal solder (inside the barrel) type. Are there any you've found which you consider of better quality than average?

I'd like to upgrade the umbilical on the DC power supply to my Graham Slee Reflex X phono stage, (Belleson SuperPower regulator already installed) and those CCTV plugs look like they'll work well.
- RE: I'm looking forward to your report - Duster 11:36:08 04/21/15 (14)
  Yes, the DC plug is marketed as a CCTV DC connector, since installers in the field tend to favor set-screw or compression connectors rather than solder type connectors. You are spot-on about the observation that it should provide more user friendly termination of heavier gauge wire vs. a narrow barrel DC connector. I haven't noticed any sources offering CCTV DC plugs that are of better quality than others. It's a pretty straightforward design, nothing audiophile about it, per se. Similar set-screw type connectors are also used for distributed audio systems.
  - RE: "nothing audiophile about it, per se" - 1973shovel 18:15:22 04/21/15 (13)
    I just thought I'd ask. I figured if anyone had a line on a DC plug of better quality, it would be you.
    
    I'm planning on hard-wiring mine at the power supply end, using 18 ga. silver plated Teflon wire. The quiescent draw of the Slee phono stage is 30 mA @ 24 VDC, so even 18 gauge is serious overkill.
    
    I'd like to hard-wire the Slee end too, but will have to see if I can bypass the DC input jack without ruining it. I have no plans to sell it, but you never know.
    
    "You won't come back from Fletcher-Munson curve"-Jan and Dean
    - Much better DC power plugs do exist .. .like xt60 - beppe61 00:08:31 04/24/15 (9)
      a little DIY is needed but there is no comparison with the usual dc power plugs that in some cases are very poor quality.
      Why to spend big money on a connector inferior by design when you can have exceptional connectors for almost nothing ?
      
      Kind regards,
      bg
      http://www.ebay.com/itm/1pcs-NEW-XT60-Bullet-Connectors-Plug (Open in New Window)
      Edits: 04/24/15
      - Those look very nice indeed, but there's one problem - 1973shovel 09:17:44 04/25/15 (8)
        
        In Reply to: RE: Much better DC power plugs do exist .. .like xt60 posted by beppe61 on April 24, 2015 at 00:08:31
        
        "Does not ship to United States" according to the ebay listing. That means I can't get them.
        
        Thanks for making me aware of them though. Perhaps I can find another source.
        
        "You won't come back from Fletcher-Munson curve"-Jan and Dean
        
        Oops - 1973shovel 09:33:51 04/25/15 (7)
        
        In Reply to: RE: Those look very nice indeed, but there's one problem posted by 1973shovel on April 25, 2015 at 09:17:44
        
        Guess I should have Googled before I posted. It looks like I can get five pair of the XT60s for $3.80, and free shipping.
        
        Thanks for making me aware of these, beppe61!
        
        "You won't come back from Fletcher-Munson curve"-Jan and Dean
        XT60 at Amazon (Open in New Window)
        
        The XT60 appears to be an inline connector. - Duster 09:07:28 04/27/15 (5)
        
        In Reply to: RE: Oops posted by 1973shovel on April 25, 2015 at 09:33:51
        
        The XT60 appears to be an inline connector -- a quick-disconnect butt joint connector.
        
        There's no XT60 jack I can find that can be installed on the chassis of a power supply or component.
        
        While the gold plated contacts look very nice, an XT60 connector won't work for a DIY DC umbilical project.
        
        See link:
        
        https://www.google.com/search?newwindow=1&safe=off&biw=1440& (Open in New Window)
        
        It depends on the device you're powering - 1973shovel 18:08:32 04/27/15 (4)
        
        In Reply to: RE: The XT60 appears to be an inline connector. posted by Duster on April 27, 2015 at 09:07:28
        
        It will work, but it's going to require more work. The chassis mounted jack would have to be removed, and a short umbilical would have to be added, along with strain relief.
        
        Is it worth it? I guess it depends on whether it is believed (via listening), or could be proven (with a scope) that the XT60 is somehow adds less noise to the DC you're feeding in than a standard DC jack and plug. I've give it some thought, and I don't think I'll be reworking a $1200 phono stage just to find out. I'm going to stick with the CCTV type plug you recommended, and leave the jack alone.
        
        Thanks again.
        
        "You won't come back from Fletcher-Munson curve"-Jan and Dean
        
        RE: It depends on the device you're powering - Duster 20:37:49 04/27/15 (3)
        
        In Reply to: RE: It depends on the device you're powering posted by 1973shovel on April 27, 2015 at 18:08:32
        
        Your thinking is reasonable regarding an otherwise captive DC umbilical, with an XT60 quick-disconnect mounted inline in order to separate the PSU from the component without using chassis-mount jacks. However, that approach would negate the ability to swap-out DC umbilical cords.
        
        I finished the DIY 16 AWG mil-spec DC umbilical project today. SPC/PTFE Teflon mil-spec wire implemented for DC applications takes ages to burn-in, so it will be a while before I can post a proper report. However, I can say at this early stage there are sonic aspects that are definitely more impressive than what the stock 18 AWG PVC DC umbilical provides. This is no real surprise, since I've built seven DIY mil-spec DC umbilicals over the years, and none of them were disappointing after ample burn-in time. I had as much fun as ever building this one as I had with any other one I've built. I'll post information with special tips about the DIY mil-spec DC umbilical project sometime down the road.
        
        The CCTV DC plug is an excellent professional installation connector. Good build quality, and the tiny termination slots with set-screws are similar to AC plug termination slots. The small clamping mechanism actually provides a very solid grip if you use a good quality small screw driver for the task. The 16 AWG mil-spec wires fit perfectly into the slots. It's about as good as it gets if you seek a solderless DC connector, and I would definitely choose it again over a typical narrow barrel DC plug. That said, I'd still like to know how much better the premium Oyaide DC plug might perform.
        
        RE: It depends on the device you're powering - ipdtt 12:38:23 04/28/15 (2)
        
        In Reply to: RE: It depends on the device you're powering posted by Duster on April 27, 2015 at 20:37:49
        
        The "XT60 Bullet Connectors Plugs" were designed for R/C = radio controlled cars, boats, planes, ect. to connect lipo battery packs to the Speed Controllers, they are not audio quality connectors. The gold plating will flake off the connectors quickly. I know this because (i have used the XT60 plugs) i am into R/C big time and there are better plugs for R/C then the XT60 connectors.
        ~D
        
        Wherever you go there you are.
        
        Edits: 04/28/15
        
        Thanks for the heads-up (nt) - Duster 14:38:25 04/28/15 (0)
        
        In Reply to: RE: It depends on the device you're powering posted by ipdtt on April 28, 2015 at 12:38:23
        
        nt
        
        RE: It depends on the device you're powering - ipdtt 13:03:56 04/28/15 (0)
        
        In Reply to: RE: It depends on the device you're powering posted by ipdtt on April 28, 2015 at 12:38:23
        
        +1 "I'd still like to know how much better the premium Oyaide DC plug might perform"
        
        ~D
        Wherever you go there you are.
        
        RE: Oops - beppe61 14:15:00 04/25/15 (0)
        
        In Reply to: RE: Oops posted by 1973shovel on April 25, 2015 at 09:33:51
        
        Hi and you are welcome !
        They are recommended for low voltage high current applications, but i guess they should be ok also for lower currents. The execution of contacts looks pretty good and much better than common dc plugs.
        And they are quite affordable also.
        Kind regards,
        bg
    - RE: "nothing audiophile about it, per se" - Duster 09:23:50 04/22/15 (2)
      The Oyaide DC-2.1G and Oyaide DC-2.5G are the nicest DC plugs I've come across, but the design has the same issue of being a narrow barrel type connector. It's unknown whether or not the premium Oyaide connector would be worth its price point for my particular application.
      - RE: "nothing audiophile about it, per se" - ipdtt 16:14:31 04/22/15 (1)
        
        In Reply to: RE: "nothing audiophile about it, per se" posted by Duster on April 22, 2015 at 09:23:50
        
        The Oyaide DC-2.1G
        See link:
        Wherever you go there you are.
        http://www.ebay.com/itm/Oyaide-DC-2-1G-24K-Gold-Plated-DC-Po (Open in New Window)
        
        RE: "nothing audiophile about it, per se" - ipdtt 16:17:40 04/22/15 (0)
        
        In Reply to: RE: "nothing audiophile about it, per se" posted by ipdtt on April 22, 2015 at 16:14:31
        
        The Oyaide DC-2.5G
        See link:
        Wherever you go there you are.
        http://www.ebay.com/itm/Oyaide-DC-2-5G-24K-Gold-Plated-DC-Po (Open in New Window)

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