Part 2 – The materials.
OK, to work.
The conductors for the interconnect come from CAT 5e Plenum cable. You will need somewhat longer CAT 5e cable than twice the length of your desired interconnects. Why CAT 5e plenum? CAT 5 cable uses OFC. Of course it likely is only 4N vs. 5N or 6N that most audiophile cables use but…..at what cost? It is important to use the plenum version of CAT 5e to get the required Teflon (FEP) insulation. Even so, check the supplier’s specification for the cable via the internet. Not every CAT 5e uses FEP. In my case I got my cable from the local Home Depot and it had 3 pairs using FEP and the other pair was Polyolefin. The wire is 24 AWG solid copper, so this is keeping with my desire to minimize the conduction path material. I also find that the solid conductor does very well for higher frequencies.
The core for the interconnect uses ¼ inch diameter cotton cord. (Make sure it is 100% cotton.) Why cotton? Look it up on a dielectric constant chart http://www.asiinstr.com/technical/Dielectric%20Constants.htm#Section%20C and you will see that cotton has a value of 1.3-1.4. This is even lower than Teflon at 2.0. Get more of this cord than you think you need, this will allow you to use the extra to help in the building of the cable. Note, do not cut the cord to length yet, leave it full length for now.
You will need some Teflon tape to wrap the cable. You can use the standard plumbers tape available at your hardware store. I could only get ½ inch width and that was fine. If you can get ¾ or 1 inch wide even better as it makes the wrapping process quicker.
You will need an outside jacket for the finished cable. I used what I had on hand. If you can get cotton shoe laces with the wider, tubular, lacing you could use that. Again, cotton should give excellent results due to the low dielectric constant. Since there is a coating of Teflon tape over the cable before the jacket goes on the jacket material is not so critical. Of course if you have a low dielectric constant materials available then use them!
You will need some short pieces of heat shrink to fix the jacket in place on the cable. You also need a couple of short pieces of heat shrink to lock the wires to the core at the start of the wire wrapping process (this will become clearer during the building instructions).
In keeping with the goal of using the minimal amount of material in the conduction path I used Eichmann bullet plugs. I do recommend them as they work well for me, but you can use whatever your favorite RCAs are. Although the bullet plugs worked well for me I did use some cheap “Source (Circuit City)” RCAs in an earlier proto-type. This proto-type required some extra burn in to get good results and I’m sure the cheaper plugs did degrade the results a little. The Eichmann plugs were the only item that wasn’t easily available and had to be ordered. This was also the only really expensive parts used, but from what I heard they were worth it.
Solder…I happened to have some silver solder so I used it. I would recommend silver solder but I don’t think this will make or break the project.
Packing tape….I use tiny strips of packing tape to hold the wires in place before getting the heat shrink in place. Why packing tape? Because the standard packing tape has a plastic base that is also a low dielectric constant material.
That’s it; nothing more exotic.
Except for bullet plugs you should be able to pick up the materials just about anywhere.
Wire preparation:
To make this interconnect you will need to separate the CAT 5e wires into individual strands.
First, strip the outer jacket off of one end. A short length of 3 – 4 inches is all that is required. You need to be able to get to the rip core (string in between the wires). Make a small slit in the jacket insulation on the end of the cable you just stripped. (This gives the rip cord a starting point to cut through the jacket.) Firmly grasp the rip cord in one hand a rip it down through the jacket of CAT 5e cable from one end to the other.
Now you can remove the jacket from the CAT 5e cable. You will now have four pairs of wires. Each pair will be twisted together. Identify which pairs have the appropriate insulation (FEP), these are the wires we will be using.
The easiest way to identify the FEP coated wires is to look up the manufacturer’s information on their web site. If that doesn’t work, or isn’t available, then here is a trick you can use.
Teflon insulation has a higher melting temperature than the Polyolefin so just touch a soldering iron briefly to the insulation. With Teflon a brief touch does not really melt the insulation and the soldering tip can easily slide up and down the insulation (provided you don't use too high a temperature or leave it in one place too long). With the Polyolefin when the tip touched the insulation it melts the insulation and sinks into the insulation.
Now you have to untwist the wires (we need individual strands). I suppose there must be some quick way of doing this but…I didn’t use it. I just clamped one end of a pair of wires in a vice, stretched out the wire and then began untwisting. It takes a bit of time but it’s not too bad.
Now you need to straighten the waves out of the strands. The easiest way to do this is to clamp one end of the wire in a vise. Take the other end in your hand and walk out until the wire is straight and suspended in the air between you and the vice. First, firmly but gently apply pressure to the wire (pull); not too hard but you should feel the wire stretch just a little bit. Now quickly ease the pressure off the wire (let it slacken a little) and then snap it tight again. Do this two or three times and you should have a straight wire. To ensure it was straight I went back to the end clamped in the vice and grabbed with wire with a cloth rag. I then walked back to the other end of the wire dragging the wire through the cloth in my hand. This pressure helps straighten any last waves in the insulation. You can now roll up the wire on reels or what ever you have to wrap it on until you can use it,
You are now ready to start making your interconnects.
ROVA
OK, to work.
The conductors for the interconnect come from CAT 5e Plenum cable. You will need somewhat longer CAT 5e cable than twice the length of your desired interconnects. Why CAT 5e plenum? CAT 5 cable uses OFC. Of course it likely is only 4N vs. 5N or 6N that most audiophile cables use but…..at what cost? It is important to use the plenum version of CAT 5e to get the required Teflon (FEP) insulation. Even so, check the supplier’s specification for the cable via the internet. Not every CAT 5e uses FEP. In my case I got my cable from the local Home Depot and it had 3 pairs using FEP and the other pair was Polyolefin. The wire is 24 AWG solid copper, so this is keeping with my desire to minimize the conduction path material. I also find that the solid conductor does very well for higher frequencies.
The core for the interconnect uses ¼ inch diameter cotton cord. (Make sure it is 100% cotton.) Why cotton? Look it up on a dielectric constant chart http://www.asiinstr.com/technical/Dielectric%20Constants.htm#Section%20C and you will see that cotton has a value of 1.3-1.4. This is even lower than Teflon at 2.0. Get more of this cord than you think you need, this will allow you to use the extra to help in the building of the cable. Note, do not cut the cord to length yet, leave it full length for now.
You will need some Teflon tape to wrap the cable. You can use the standard plumbers tape available at your hardware store. I could only get ½ inch width and that was fine. If you can get ¾ or 1 inch wide even better as it makes the wrapping process quicker.
You will need an outside jacket for the finished cable. I used what I had on hand. If you can get cotton shoe laces with the wider, tubular, lacing you could use that. Again, cotton should give excellent results due to the low dielectric constant. Since there is a coating of Teflon tape over the cable before the jacket goes on the jacket material is not so critical. Of course if you have a low dielectric constant materials available then use them!
You will need some short pieces of heat shrink to fix the jacket in place on the cable. You also need a couple of short pieces of heat shrink to lock the wires to the core at the start of the wire wrapping process (this will become clearer during the building instructions).
In keeping with the goal of using the minimal amount of material in the conduction path I used Eichmann bullet plugs. I do recommend them as they work well for me, but you can use whatever your favorite RCAs are. Although the bullet plugs worked well for me I did use some cheap “Source (Circuit City)” RCAs in an earlier proto-type. This proto-type required some extra burn in to get good results and I’m sure the cheaper plugs did degrade the results a little. The Eichmann plugs were the only item that wasn’t easily available and had to be ordered. This was also the only really expensive parts used, but from what I heard they were worth it.
Solder…I happened to have some silver solder so I used it. I would recommend silver solder but I don’t think this will make or break the project.
Packing tape….I use tiny strips of packing tape to hold the wires in place before getting the heat shrink in place. Why packing tape? Because the standard packing tape has a plastic base that is also a low dielectric constant material.
That’s it; nothing more exotic.
Except for bullet plugs you should be able to pick up the materials just about anywhere.
Wire preparation:
To make this interconnect you will need to separate the CAT 5e wires into individual strands.
First, strip the outer jacket off of one end. A short length of 3 – 4 inches is all that is required. You need to be able to get to the rip core (string in between the wires). Make a small slit in the jacket insulation on the end of the cable you just stripped. (This gives the rip cord a starting point to cut through the jacket.) Firmly grasp the rip cord in one hand a rip it down through the jacket of CAT 5e cable from one end to the other.
Now you can remove the jacket from the CAT 5e cable. You will now have four pairs of wires. Each pair will be twisted together. Identify which pairs have the appropriate insulation (FEP), these are the wires we will be using.
The easiest way to identify the FEP coated wires is to look up the manufacturer’s information on their web site. If that doesn’t work, or isn’t available, then here is a trick you can use.
Teflon insulation has a higher melting temperature than the Polyolefin so just touch a soldering iron briefly to the insulation. With Teflon a brief touch does not really melt the insulation and the soldering tip can easily slide up and down the insulation (provided you don't use too high a temperature or leave it in one place too long). With the Polyolefin when the tip touched the insulation it melts the insulation and sinks into the insulation.
Now you have to untwist the wires (we need individual strands). I suppose there must be some quick way of doing this but…I didn’t use it. I just clamped one end of a pair of wires in a vice, stretched out the wire and then began untwisting. It takes a bit of time but it’s not too bad.
Now you need to straighten the waves out of the strands. The easiest way to do this is to clamp one end of the wire in a vise. Take the other end in your hand and walk out until the wire is straight and suspended in the air between you and the vice. First, firmly but gently apply pressure to the wire (pull); not too hard but you should feel the wire stretch just a little bit. Now quickly ease the pressure off the wire (let it slacken a little) and then snap it tight again. Do this two or three times and you should have a straight wire. To ensure it was straight I went back to the end clamped in the vice and grabbed with wire with a cloth rag. I then walked back to the other end of the wire dragging the wire through the cloth in my hand. This pressure helps straighten any last waves in the insulation. You can now roll up the wire on reels or what ever you have to wrap it on until you can use it,
You are now ready to start making your interconnects.
ROVA