I hit a homerun with my homemade balanced IC's

Tweakers' Asylum

Tweaks for systems, rooms and Do It Yourself (DIY) help. FAQ.

Just completed a pair of balanced IC's last night, and I can already say, after only a few hours of break-in, that they surpass anything I've heard in my system so far, and that includes copper and silver cables, with real purdy jackets and logos, that sell for around a grand per meter. This pair costs less than a hundred dollars and took about 8 hours to build, even with multiple screw-ups. Am I delusional? Is my objectivity skewed by "built it mah self" pride? Probably no more than your objectivity was skewed after plunking down hundreds of bucks for that pair of fancy bungee cords that hold your components together.
I spent dozens of hours researching various construction techniques. Although I'm not an engineer, I have a layman's grasp of electrical principles as they relate to signal transmission. There are not many postings or articles regarding balanced IC's, but I stole ideas from the single-ended stuff and applied it to the balanced configuration. I am very happy to say that my choice of architecture and materials resulted in a cable that is detailed without being bright, is very 3D and very quiet (even with no shielding), has solid bass, lifelike midrange, and amazing dynamics. I am not especially skilled at soldering, but even my horrid attempts were adequate for the success of this design. Someone who is really good at fine work like this might get even better results. I urge you to at least attempt making a pair. The worst thing that can happen is you'll need to enlist the assistance of aomeone who can handle the soldering, or you'll have a few dollars worth of junk laying around. How much have you spent (or wasted) on cables so far?
These 24" cables connect my Marantz SA-11S1 SACD player to a Sonic Euphoria preamp with, of course, balanced inputs. These are not at all delicate like so many homemade versions, but the drawback is their stiffness, with about a 4" to 5" bend radius (that means a 8" to 10" wide U). Do NOT try to turn a sharp corner with these babies. Actually, please do try and let me know what happens.
The cable consists of a pair of 18ga OCC copper/teflon hookup wires spiraled in parallel around 1/8" diameter teflon tubing. It's not cheap, but I'm almost certain that this particular wire, available from VH Audio, contributes significantly to the smoothness and rich detail of the cable. The spacing of the twists is probably not critical: mine are about two inches per complete revolution around the teflon core. What is probably more important, and difficult to achieve, is the evenness of the spacing between the two signal wires: they should be on opposite sides of the teflon core along its entire length. I used heatshrink to hold them in place, but even that didn't keep them perfectly aligned. You'll need to fuss with it some in order to get a smooth spiral. Take your time. The last couple inches on each end should be straight instead of spiral twisted, but the two wires should still be parallel and on opposite sides of the teflon tube core.
This subassembly is then slipped into a 3/8" OD x 5/16" ID FEP teflon tube, available from McMaster-Carr. The wall thickness can be only 1/32" or the tube won't bend at all. It's not a tight fit, but the tubing will not be straight, so the innards will probably bind against the walls of the larger tube. I rubbed a very little dish soap on the inner pair, and it all slipped right into place.
So you've got a plastic tube with two twisted wires that look like a barber pole inside it. Now comes the ground wire, which can be a lower quality material because it does not carry the signal. It should, however, be heavier gauge than either signal wire. I used some stranded silver wire I had laying around, probably about 16 or 14ga. This wire is spiraled around the outside of the plastic tubing, in the opposite direction of the spiral of the wires inside the tubing. This can also be fixed in place with heatshrink.
Now you have a decorative piece of tubing with three loose wires hanging on each end which need connectors. I used Vampire XLR plugs because they can almost accept 3/8" tubing. Yes, almost. Time to get out the Dremel and enlarge the opening of both male and female plugs. First, remove the guts, of course, and then grind the ID of the throat of each plug until you get about 5/16" diameter. Do not grind on the sides of the holes, or you'll wreck the tapped holes that hold the strain relief clamp. You might need to make final adjustments by hand with a small round file. When you put a piece of scrap tubing in the opening, the strain relief clamp should be about 1/16" away from its tight position on both sides of the clamp. This clamping pressure is what holds the cable together and gives it plenty of strength. The plug material is very soft, and grinds quite easily. Takes about ten minutes to do male and female. Hope you bought an extra plug in case you wreck one!
How to get the ground wire, on the outside of the tube, into the plug through the opening, which is even smaller than just the tube by itself? Simply drill a small hole through one wall of the tubing and thread the ground wire into the inside of the tube for the last inch or two. I found that putting the hole an inch from one end, and two inches from the other end, of the large tube allowed enough space to slip the plug body back while soldering leads.
Now the large tube has two wires inside it, spiraled around a smaller tube, with a larger ground wire wrapped around the outside of the large tube in an opposing spiral, and, on each end, an inch or two of ground wire inside. So, three wires sticking out each end. You can push the entire inner assembly through the tube so that enough wire sticks out on the end with the hole spaced one inch from the end to enable assembling the plug. I slipped a loose piece of heatshrink onto the large tube, then the plug body, then soldered the leads. Carefully pull the extra inner wires back toward the other end, aligning the plug parts so they'll slip together. When everything is snug, tighten the strain relief clamp around the large tube. There should be just a little resistance on the screws as the clamp tightens onto the large tube OD. Tighten it all the way, and the tube should be held fast. Then finish the other end by trimming and soldering the leads. The second end will be a lot tighter quarters for soldering because you don't have the luxury of pulling extra wire through to allow room to work. Hope you have an extra plug to replace the one you'll wreck! The nice thing about XLR plugs is that they're much more robust and easier to solder than RCA plugs. However, once you get solder on the connecting pins, it is almost impossible to reuse them. You're better off throwing it away and starting over with the pins from another plug. They cost only a few bucks each. You can still use the ground-out body.
Shrink the heatshrink tubing on each end so it covers the hole where the ground wire passes through the tube wall. CRUCIAL disclaimer: unless you are VERY careful about connecting both ends of each wire to the correct pins, you better do a polarity/continuity check. If you cross the wires somehow, you might destroy equipment, or at least get crappy sound. If everything checks okay, hook 'em up already! You will be amazed that your expensive purchased wire is so easily and thoroughly bested by this humble homebrew. This design is a bit eccentric, but the small cost and minimal effort invested for such a significant reward validate it completely. I urge you to give this a try, and then please report back here with your results, good or bad.
Peace,
Tom E

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Topic - I hit a homerun with my homemade balanced IC's - madisonears 20:52:20 03/20/07 (6)

Interesting - Jon Risch 13:39:04 03/24/07 (2)

Jon: I'm happy you saw and responded to my post - madisonears 20:09:14 03/28/07 (1)

Good - Jon Risch 20:38:32 03/29/07 (0)

Re: I hit a homerun with my homemade balanced IC's - DaveT 06:52:00 03/21/07 (0)

Congrats! - Bixby 06:40:06 03/21/07 (1)

Re: Congrats! - madisonears 12:51:47 03/21/07 (0)

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