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Paging Mr. Cowen....

68.227.247.96

Posted on December 29, 2016 at 17:13:12
alan m. kafton
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Joined: April 7, 2000
Contributor
  Since:
March 24, 2012
How is your new hand-built linear power supply doing?

 

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RE: Paging Mr. Cowen...., posted on December 30, 2016 at 12:53:47
bcowen
Audiophile

Posts: 544
Location: North Carolina
Joined: December 19, 2015
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  Since:
January 1, 2017
Howdy Alan!

So far so good. I used the larger heat sinks on it so even with it left on all the time, the sinks are barely warm and the outer case stays at room temp. Can't say that it's a night and day difference over the iPower wall wart though. There's a bit more ease in the treble and a bit more snap on transients, so the changes I do hear are all positive. Just not monumental. Perhaps the iPower supply is better than I gave it credit for, or perhaps the Remedy re-clocker isn't terribly sensitive to the power feeding it. Either way, I enjoyed building it and didn't spend a bunch of money in the process, so all very worthwhile to me.

 

RE: Paging Mr. Cowen...., posted on December 31, 2016 at 13:40:35
Duster
Audiophile

Posts: 12361
Location: Pacific Northwest
Joined: August 25, 2002
Hi bcowen,

Do you have a link to the details of your project, or could you post them in this thread? What DC umbilical are you using for the PSU?

Cheers, Duster

 

RE: Paging Mr. Cowen...., posted on December 31, 2016 at 14:50:10
bcowen
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Posts: 544
Location: North Carolina
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Hey Duster,

Link below to the (nearly) finished unit. The basis of the kit is the AMB Sigma 11 ( http://www.amb.org/audio/sigma11/ ). For the umbilical, I'm using an Oyaide DC2.1G plug on the load end with Canare star-quad cable -- four 24 gauge copper conductors and a braided tinned copper shield (connected at the source end only). Source end of the cable is connected directly to the terminal blocks in the unit, no plug. Got most of the parts that weren't supplied by AMB from Mouser, and got the case on Ebay.

 

RE: Paging Mr. Cowen...., posted on December 31, 2016 at 16:11:58
Duster
Audiophile

Posts: 12361
Location: Pacific Northwest
Joined: August 25, 2002
Nice project, bcowen!

Just a note about the DC umbilical that might be a factor in the performance of your DIY PSU. The 4-conductor Canare cable features a solid PE (polyethylene) dielectric, which tends to store energy more (higher dielectric constant) than a foamed/cellular PE dielectric. Since the Canare cable is wired cross-connected (star quad), capacitance is increased vs. a twisted pair, of which when combined with the higher dielectric constant solid PE, the higher capacitance tends to impart even greater coloration due to slower release of stored energy within the dielectric. Additionally, a braided shield slipped over the DC umbilical also increases capacitance, so this issue might be a factor in how the performance of the PSU is evaluated. You might consider removing the braided shield, since a star quad geometry is self-shielding and does not require additional shielding (perhaps too much of a good thing) for low-noise performance. I hope this matter is considered a helpful effort rather than any form of criticism on my part, bcowen :-)

You might be interested in an inexpensive DIY DC umbilical project built from scratch that I've enjoyed making this year. It's an easy thing to do if patience is a virtue, especially if a 0.5 meter DC umbilical is long enough for your low-current application:

All it requires is a two foot length of red 21 AWG VH Audio UniCrystal OCC Copper Hookup Wire with AirLok Insulation, a two foot length of the white version hookup wire, and a roll of PTFE Teflon plumber's tape. Total cost is under $15 (not including the cost of connectors) and some careful effort. The key benefits of the DIY OCC Airlock build is the implementation of 21 AWG single-crystal solid core copper wire with foamed/cellular FEP Teflon dielectric for ultra-low dielectric involvement and capacitance (much better than even a foamed/cellular PE dielectric), the benefit of a solid core OCC copper conductor, and the ability to form a very tight twist ratio for optimized noise cancellation without need of additional shielding. The low-mass foamed/cellular FEP Teflon dielectric allows the best formed tightly-twisted DIY cable ever in my experience, and I've enjoyed building several DIY cables with it that outperform a number of commercially built twisted pair cables. I'll be glad to post instructions if you wish.

Cheers, Duster

See link:

 

RE: Paging Mr. Cowen...., posted on January 1, 2017 at 04:44:40
bcowen
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Posts: 544
Location: North Carolina
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January 1, 2017
Hi Duster,

I'm always interested in your ideas and shared experiences, so please do post the instructions. One nice thing with a DIY box like this is since I know how it goes together I can rip into it with ease. :)

I have some Neotech 20 gauge UPOCC/teflon wire on hand, although the teflon is solid rather than foamed. Do you think the foamed versus un-foamed is a huge factor, or is it more in the quality of the wire and the construction details? Very easy for me to try your technique without having to buy anything, unless you think the foamed dieletric will be a significant factor.

Thanks!





 

RE: Paging Mr. Cowen...., posted on January 2, 2017 at 15:06:59
Duster
Audiophile

Posts: 12361
Location: Pacific Northwest
Joined: August 25, 2002
You could use the 20 AWG Neotech solid core OCC copper with *solid* FEP Teflon wire for a DIY DC umbilical project, but I'm very pleased with VH Audio's UniCrystal OCC Copper Hookup Wire with *foamed/cellular* AirLok Insulation. I've built a number of short 0.5 meter AES/EBU digital cables and DC umbilicals with 21 AWG VH Audio UniCrystal OCC Copper Hookup Wire with *foamed/cellular* AirLok Insulation, 22 AWG Neotech solid core OCC copper with *solid* FEP Teflon wire, and 22 AWG Neotech solid core pure silver with *solid* FEP Teflon and find that the *solid* FEP dielectric vs. the superior *foamed/cellular* FEP Teflon AirLok dielectric involves two issues:

The VH Audio Airlock dielectric is comparatively thin walled and the low-mass insulation adds very little material to "get in the way" of the solid core wire twist ratio, while the solid insulation does not allow as tight of a twist ratio for optimized noise cancellation, and IME the solid insulation imparts a subtle "Teflon sonic signature" that the Airlock dielectric does not, so the Airlock insulation is quite transparent sounding, to my ear. It's also rather easy to achieve a somewhat precision twist ratio that is considerably consistent (but not perfect) from end to end, along the entire length of the cable, with only a couple of inches at each end that need to be snipped-off as waste caused by the twisting process and the securing of the ends during the wire twisting process.

The wire twisting process is simple but effective in order to build a short-length cable, with only two factors to consider:

1. An unmovable object like a table vice or a chair back to tie one end of the wires to.

2. A simple stick, pen/pencil, or other handy device to use as a twisting rod secured at the other end of the wires.

Twisting:

Starting out with the two wires pulled straight in parallel, begin turning the twisting rod in a clockwise direction while observing how the wire behaves when the two wires begin to twist together, since the twists may form at arbitrary places along the length of the wires. With one hand turning the rod, use the other hand to run fingers along the length of the wires to help spread-out the twists so the wires don't bunch too much together in one spot. You may notice that the more you twist, the more the wires will start to follow a pattern that needs to be guided by the fingers so the twists are evenly spread-out along the entire length of the wires. The more the wires are twisted together, the more you will need to stop the twisting process from time to time and be more assertive to help spread the twists more evenly rather than allowing the wires to severely bunch together. As the wires begin to form a consistently tight twist ratio, you may notice a point where the wires seem as tightly twisted as they can be, but after the wires are allowed to rest awhile, you may find they can be twisted even tighter, but don't be too severe. As the wires are twisted to a nominal maximum ratio, you may notice that at each end of the wires, the twists will be come very severe which is a sign that the wire twisting process is completed. The severely twisted ends should be snipped-off before the next step begins.

PTFE Teflon tape wrap:

Once the wires are twisted and removed from the table vice or other object, and the twisting rod removed, a layer of PTFE Teflon plumber's tape wrap should be used to build a cable jacket to help keep the wires twisted tightly together, and provide a level of of cable resonance control. I recommend heavy duty gray colored PTFE tape, since only one layer is required vs. the very thin white PTFE Tape that is very inefficient to work with. Simply wrap the wires like you would a baseball bat or golf club grip, keeping the tape snug while wrapping the wires. This wrapping process is the most tedious aspect even for a short 0.5 meter DIY cable build, and can result in tired fingers due to keeping the tape consistently snug along the entire length of the cable during the wrapping process.

Cheers, Duster

 

RE: Paging Mr. Cowen...., posted on January 2, 2017 at 16:33:32
bcowen
Audiophile

Posts: 544
Location: North Carolina
Joined: December 19, 2015
Contributor
  Since:
January 1, 2017
Duster,

Thanks for the detailed info and instructions. I'll order some of the VH wire and put a new umbilical together, and post back with how it turns out.

Thanks again!

 

RE: Paging Mr. Cowen...., posted on January 2, 2017 at 16:55:09
Duster
Audiophile

Posts: 12361
Location: Pacific Northwest
Joined: August 25, 2002

Another handy tool for a DIY cable project is 3M Nexcare Transpore perforated PE medical tape that works very well as a cable outer diameter build-up material at the ends of a cable when terminating thin cables rather than use layers of heat shrink for the task. The Nexcare tape available at any drug store can be layered to the exact thickness required for securing an otherwise too small cable to fit snugly into various connector entry points, for set-screw or crimp-type strain relief mechanisms.

Another important issue I forgot to mention is that the finished cable should be covered with Techflex sleeving, since the PTFE Teflon tape wrap jacket can be easily damaged if not protected by sleeving vs. what more durable cable jackets can provide.

 

RE: Paging Mr. Cowen...., posted on January 2, 2017 at 17:36:34
bcowen
Audiophile

Posts: 544
Location: North Carolina
Joined: December 19, 2015
Contributor
  Since:
January 1, 2017

Good to know, thanks.

Just sent an order in to Chris, but he's off to CES so it'll be another week before he can ship. But that will give me the time to listen to the Christmas present I bought myself (I couldn't put it on my Santa list for fear of guys in white uniforms appearing at the front door). :)






 

RE: Paging Mr. Cowen...., posted on January 2, 2017 at 17:43:46
Duster
Audiophile

Posts: 12361
Location: Pacific Northwest
Joined: August 25, 2002
BTW, note the edited text about covering the DIY cable with Techflex sleeving in order to protect the PTFE Teflon tape wrap jacket.

 

Twist Ratio, posted on January 2, 2017 at 18:04:08
Duster
Audiophile

Posts: 12361
Location: Pacific Northwest
Joined: August 25, 2002



The twist ratio a.k.a twist pitch or twist rate should appear at least as tight as the tightest twisted pair shown in the image of this Cat6a cable.

 

RE: Twist Ratio, posted on January 15, 2017 at 07:22:26
bcowen
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Posts: 544
Location: North Carolina
Joined: December 19, 2015
Contributor
  Since:
January 1, 2017

Received the wire from Chris. Hope to get time this afternoon to put it together. Question for 'ya: I have some 3/8" PTFE thin-wall heat shrink tube that looks to be just the right size (once shrunk) to fit tightly around the twisted pair. Thoughts on using it versus the teflon tape? Would be much easier, and if the main purpose of the teflon tape is to hold the wire twist together tightly, it would do an even better job at that. But not sure if there would be any sonic penalty....

Thanks!




Duster,

 

RE: Twist Ratio, posted on January 16, 2017 at 14:27:02
Duster
Audiophile

Posts: 12361
Location: Pacific Northwest
Joined: August 25, 2002
If the PTFE heat shrink tube is truly thin-wall and allows the cable to be fairly flexible, I think it could indeed be a good thing.

I'll be interested in how well it holds the wires firmly together, and if the tautness remains stable over the test of time.

Thin-wall polyolefin stretches too easily, but PTFE Teflon is a different animal.

 

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