Cable Building

Discussion in 'DIY' started by Skyline, Sep 30, 2015.

Tags:
  1. Armaegis

    Armaegis Friend

    Pyrate BWC
    Joined:
    Sep 27, 2015
    Likes Received:
    7,463
    Trophy Points:
    113
    Location:
    Winnipeg
    Not quite. You want low values of everything. Those 50/75/110ohm specs are all "characteristic impedance" which is not the same as resistance or even regular impedance.
     
  2. aufmerksam

    aufmerksam Friend

    Pyrate
    Joined:
    Sep 28, 2015
    Likes Received:
    1,337
    Trophy Points:
    93
    Location:
    E. Lansing, MI
    @Armaegis is correct.

    A little more detail: When coax specifies a characteristic impedence of 50 or 75 ohm or whatever, that is crucial for digital applications, where the sending and receiving devices are expecting the signal to go through such a cable. (For example 75 is used for digital coax because it offers the best compromise of low attenuation and low capacitance for the cost). Success for digital coax relies on the signal fitting the expected parameters so it can be correctly read and converted by the DAC end of the chain.

    With standard RCA that isn't typically the case since you are sending an analog signal, and typically over very short distances You just want the signal to get there unmolested. It isn't carrying high power, and it doesn't need to be converted. Also, the is often a huge mismatch in the output impedance in the DAC (low) and the input impedence on the amp(high), so the impedence in the cable doesn't matter nearly as much as it does in the digital coax scenario. Low impedence is usually fine/good with RCA's.
     
    Last edited: Feb 5, 2017
  3. Decomo

    Decomo Almost "Made"

    Contributor
    Joined:
    Jul 1, 2016
    Likes Received:
    163
    Trophy Points:
    50
    Location:
    Australia
    Hello.. Not sure if this is right thread and if not, please discard it.

    I have Aurisonic rocket and it has one side channel issue (left side works but right side playing on and off). Hence, I took the original 3.5mm jack off and put new jack and solder it. It worked for 20 seconds and now right channel is completely dead... I thought that I did terrible job on soldering so took another brand new jack and did it again then same thing happened again. So tried another (3rd time) then same thing happen again (I am now feel depressed :(). I know that I am terrible on soldering but not sure if it is soldering issue or driver issue.

    If anyone can provide a tip or suggestion, it would be hugely appreciated.

    [​IMG]
     
  4. Grahad2

    Grahad2 Red eyes from too much anime

    Pyrate
    Joined:
    Jan 26, 2017
    Likes Received:
    1,162
    Trophy Points:
    113
    Location:
    Singapore
    You have what's called cold joints. Try to heat the jack more before you apply solder (it should flow by itself when you touch it against the jack and cable, not the iron), a good joint is shiny and not matte and bulbous.
     
  5. Decomo

    Decomo Almost "Made"

    Contributor
    Joined:
    Jul 1, 2016
    Likes Received:
    163
    Trophy Points:
    50
    Location:
    Australia
    Thank you very much for the suggestion. I will definitely try heating the jack before soldering. Hope it solves the issue. :)
     
  6. Grahad2

    Grahad2 Red eyes from too much anime

    Pyrate
    Joined:
    Jan 26, 2017
    Likes Received:
    1,162
    Trophy Points:
    113
    Location:
    Singapore
    Of course, don't heat it so much you melt the plastic. Just jab at the metal jack with the solder now and then to test the temperature.

    I.E., hold the wire and jack point together, heat the point where they meet, and dab at it with a solder strand, but NOT at the iron tip now and then. I can't really put it in words... One of those third hand things help a lot (and not human hands, you'd burn if you held the 3.5mm.)

    (It's a fine line - I've melted enough SMA connectors trying to solder to massive ground planes with a Hakko with a damaged tip... [bad day to run out of spares])
     
  7. Armaegis

    Armaegis Friend

    Pyrate BWC
    Joined:
    Sep 27, 2015
    Likes Received:
    7,463
    Trophy Points:
    113
    Location:
    Winnipeg
    If you leave the barrel off, is there sound when you press the wires directly into their proper spots with your hand/tweezers? Even if it's a bad joint, you should be able to get intermittent sound with simple physical connection. If you don't have sound with that, then there's likely a break in the wire somewhere.
     
  8. yotacowboy

    yotacowboy McRibs Kind of Guy

    Pyrate Contributor
    Joined:
    Feb 23, 2016
    Likes Received:
    10,688
    Trophy Points:
    113
    Location:
    NOVA
    Home Page:
    mildly switching topics ITT. Here's a list of cables I've got on hand for anyone wishing to add these to a lending list:
    I won't give any impressions of any of these here, so please feel free to tell me they sound like shit and are a complete waste of money. Everything's been broken in - at least 150-200+ hours on each cable. The Beldens, VHAudios and Furu receptacle have many hundreds+ hours on them. Anyhow, I'm not a Friend, so not sure how to get this going. I'm in the northern of the Virginia if there's any Friends local that want to get this potty stot-ted. G's up Hoes down, yada yada.
     
  9. Daveheart

    Daveheart Friend

    Pyrate
    Joined:
    Jan 10, 2017
    Likes Received:
    566
    Trophy Points:
    93
    Location:
    Dallas, TX
    @Torq I might be starting a couple of new cable projects soon, and I remembered you posted a picture of a sheathing tool earlier in the thread. I may end up doing something with paracord, but so far my google skills have failed to locate such a sheathing tool. Do you happen to know where to buy one or perhaps a different search I should run to find it?
     
  10. Torq

    Torq MOT: Headphone.com

    Pyrate
    Joined:
    Jan 15, 2016
    Likes Received:
    8,193
    Trophy Points:
    113
    Location:
    Seattle, WA
    I bought mine from here. It shipped the same day and arrive within two days.

    They may have them on Amazon as well. They did at the time ... but they all involved week-long shipping times AND a shipping fee that was more than the item!
     
  11. wormcycle

    wormcycle Friend

    Pyrate
    Joined:
    Aug 13, 2016
    Likes Received:
    1,506
    Trophy Points:
    113
    Location:
    Toronto, ON, Canada
    Probably too late to respond but I would try Mogami 2534 again, and I would check how the one you have was built, you may be right to be suspicious.
    I recently got free 2543 DiY cables with the amplifier that I bought and someone just cut one wire and the shield to make it 3 pin XLR. Of course the whole point is to join the pair of whites and the pair of blues, and connect the shield to ground. Properly build Mogami 2534 is superb for eliminating RFI (that from experience) and I read a post here recently that it should deliver a touch less above 10khz.
     
  12. Xen

    Xen Friend

    Pyrate
    Joined:
    Sep 30, 2015
    Likes Received:
    207
    Trophy Points:
    43
    Location:
    Houston, TX
    I would also add that when you attach the shield to the ground of the connector that you only connect it to the upstream connector. You want the interference energy to be dissipated upstream and not be sent downstream for amplification. I noticed interference in my analog chain (Gungnir Multibit RCA into BW2) and found that the interconnects had their shields soldered to the connectors at both ends. This can cause any EFI/RFI to be transmitted to the BW2 and induce a ground loop.
     
  13. wormcycle

    wormcycle Friend

    Pyrate
    Joined:
    Aug 13, 2016
    Likes Received:
    1,506
    Trophy Points:
    113
    Location:
    Toronto, ON, Canada
    I think you are right about RCA connectors. But all 3 pin XLR wiring diagrams are pretty clear what goes where. The point is to use quad cable to create two pairs of wires, and using shield as a drain.
    here is one of those XLR wiring diagrams http://www.clarkwire.com/pinoutxlrbalanced.htm
     
  14. Xen

    Xen Friend

    Pyrate
    Joined:
    Sep 30, 2015
    Likes Received:
    207
    Trophy Points:
    43
    Location:
    Houston, TX
    True, but still depends on your cable and how many signal/drain wires you have in addition to the shielding. And of the course, the biggest determinant for noise issues and the hardest to tell is whether the components (amplifier, preamp, DAC, etc) are properly grounded with regards to reference ground and chassis ground. This is a good (but kind of technical) article on the pin 1 issue: http://www.rane.com/note151.html
    A 155 slide presentation by Bill Whitlock, past President of Jensen Transformers on interference. Good practical troubleshooting advice starts around page 70-something. http://www.bennettprescott.com/downloads/grounding_tutorial.pdf

    Rane's TLDR version complete with wiring diagrams for interconnects for even the most gender "fluid" cabling (3 pin, 4 pin, 1 pin, male, female, combinations of any 2): http://www.rane.com/note110.html
     
  15. Grahad2

    Grahad2 Red eyes from too much anime

    Pyrate
    Joined:
    Jan 26, 2017
    Likes Received:
    1,162
    Trophy Points:
    113
    Location:
    Singapore
    Those FellowKids images should be a war crime via Geneva.
     
  16. wormcycle

    wormcycle Friend

    Pyrate
    Joined:
    Aug 13, 2016
    Likes Received:
    1,506
    Trophy Points:
    113
    Location:
    Toronto, ON, Canada
    Great info in the last link. But your post goes way beyond the subject of wiring and polarity of 3 pin XLR with Mogami 2534. The point is that even if you never heard about this 155 slide presentation and you manage to wire it properly you still, in most cases, get significant reduction of RFI over the 2 wire plus the shield balanced cable. I did it in two different locations and two different systems and it worked.
     
  17. AllanMarcus

    AllanMarcus Friend

    Pyrate
    Joined:
    Oct 23, 2015
    Likes Received:
    2,969
    Trophy Points:
    113
    Location:
    Los Alamos, NM
    Home Page:
    Hello folks.

    I've made a number of cables, up to 8 strand, some with each strand sleeved in 95lb paracord and some braided without sleeving. I too got the "want something more challenging" and discover kumihimo. Here's a prototype 16 strand cable I put together. Now i'm trying to decide which wire to use. The one below is striped Mogami W2799.

    I think I could go as large as 24AWG for each strand, but I really don't want to spend too much money.
    Gepco MP1201 looks interesting.
    Gotham GAC-4/1 looks good too, but the colors of the inner conductors are horrible.
    SommerCable SC-Octave also looks interesting.

    Anyone use Redco TGS-QD quad cable? Seems like good cable, and its inexpensive.



    [​IMG]
    [​IMG]
     
  18. Xen

    Xen Friend

    Pyrate
    Joined:
    Sep 30, 2015
    Likes Received:
    207
    Trophy Points:
    43
    Location:
    Houston, TX
    Puuurty! I would get lost in the pattern and have to start over... never finishing. Do you have a jig for that?
     
  19. AllanMarcus

    AllanMarcus Friend

    Pyrate
    Joined:
    Oct 23, 2015
    Likes Received:
    2,969
    Trophy Points:
    113
    Location:
    Los Alamos, NM
    Home Page:
    When I tried 16 strands by hand, I got lost. Google kumihimo; that's how I did it.
     
  20. Roarke

    Roarke New

    Joined:
    Nov 10, 2016
    Likes Received:
    2
    Trophy Points:
    3
    Location:
    Orange County
    I'd like to start making my own cables, I just finished modding my th-x00's to have mmcx connectors. I'm having trouble finding real info on making cables as opposed to snake oil wire types and "bling".

    A few questions...

    Does "braiding" have any benefits other than looks? Whether it be "microphonics" or how the cable lays? I'll be using paracord if that matters. It seems much easier to just have a single sleeve of paracord with all the wires inside.

    Realistically, why should I choose wire x over y? I'm doing these DIY to save money, so that's my number 1 factor. Any reputable starting points for wires?

    Sorry if these q's have been asked a bunch. All the diy cable info are in giant threads.
     

Share This Page