I’ve been struggling for some time to find an affordable interconnect cable choice without falling into the trap of the ultra-expensive hi-fi commercial cables. In the end, an interconnect cable has to provide low capacitance, low resistance and proper shielding to protect our desired signal from external noise. We don’t need exotic cables or connectors to achieve this. Ideal dielectric is air, but is not practical build cable using air as dielectric 🙂

I’ve some great interconnects made by my friend Vyacheslav using high-quality PTFE coaxial cable but they are very rigid so for short cables are not ideal. After exchanging some e-mails with Rod Coleman about this topic, Rod recommended me to explore the enamelled copper twisted pair option.

I looked at the great product catalogue offered by wires.co.uk and found that the TT-0190-050 red/green twisted pair enamelled 0.19mm copper cable was ideal for this purpose.  You want the cable not to be thick to avoid increasing capacitance, however it has to be thick enough to be manageable. 0.2mm is good enough for me. The twisted pair is covered by a tinned copper braid and I’m also using a PTFE transparent sleeve at the end of the cable to provide some structure and resistance to the normal use and stress which the cable must endure.

Construction process

To start we need to cut the braid to the length of the cable we want to build. Secondly we need to ensure that we provide a braid connection point to ground/earth (only at one end). It’s key you only connect the braid at one end, otherwise you are creating an unwanted earth loop. I use a 5mm copper tape to do this:

Then, the next step is to solder the tape also to the braid to provide not just a better electrical bond, but also a mechanical bond to increase the strength of the cable:

 

Once the braid sleeve is ready, we will proceed to weave the twisted pair inside the braid and add the PTFE sleeve at the ends. Also you want to add some heat shrink tubing as shown in the picture below:

The next step is to solder the connectors at each cable end. I use the metal DELTRON RCA black phono plugs from Farnell which are great value for money:

 

You also want to add some heat-shrink tubing to add resistance to the cable. We will shrink the cable tubing once we have tested the cable electrically and it works fine!

You will need a heat-gun for this though.

You don’t need to forget to solder an extra single solid core cable (mine has a PTFE sleeve) to one end and solder it to the ground of one RCA plug end to provide the necessary ground connection to the tinned-copper braid.

 

Once we tested all connections we can proceed to heat-shrink the cable tubing to finalise the interconnect cable:

The cable is solid and resistance to natural normal abuse 🙂 I’ve measured the capacitance and found that is about 140pF/m and crosstalk capacitance is just 50pF/m.

Listening to my system today with this interconnect was a great satisfaction. Expensive interconnects are a commercial myth, and here is the proven case that you can build excellent interconnects with the length you need at a very low cost.

Hope this is useful information for you to go and build your own interconnects! Please share your own experience.

Ale