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[ I'm not really certain if you advocate a shield or not - I understand the concept of spacing it adequately from the two center conductors using sheet foam, or teflon tubing/cut up inner core dialectric. ] Most people need a shield, and I recommend this over getting zapped by a CB or RFI. The shield introduces compromises in the sound, a slight dulling of transients, a loss of some air and space (no readily measurable effects on large signal amplitude response either) IF it is right next to the cable cores used for the twisted pairs. Spacing the shield away will reduce the worst of these effects to a point where it would be silly not to use the shield. See my post about McMaster-Carr DIY items over in the Tweaks section: /audio/tweaks/messages/2708.html for materials that can be used to space the shield away, and for copper braid to use for such larger shields (you can't re-use the oprioginal coax shield, as it will be too small). [ It has been written in a reply that we would already know if RFI/ EMI is a concern in our area but I'm not really sure what to listen for/ what it sounds like. I currently live in an apartment and am moving in 3 weeks to a townhouse. ] The fact that you can't always tell, and that you are moving too, augers for incoprporating a spaced shield up front. Yes, you could try them without a shield, but they might sound terribly dissapointing, and you might never know how good they could sound. [ if no shield is used....does that mean that there is only a positive connection? I am referring to the twisted pair combo 89259/89248 ] If you just make a twisted pair without shield, then you use one wire for the hot, and the other wire for the ground. Even on unbalanced/single-ended interconnects (coaxial using RCA's), the ground connection carries the signal just as much as the center wire does, there must be a 'ground return path', or no current will flow, and since none of our audio cables work on pure electrostatic principles, there must be some current flow, however minute, in order for the signal to be transfered. One question I get asked is: which center core do I use for the hot connection, and which for the ground? Theoretically, it should not matter, but with real world systems, and the possibility of differences in the ground potentials of different components, it makes sense to use the heavier gauge for the ground connect, in this case, the 89248 is the heavier of the two, so use it for the ground connection. It should not make a huge difference, but can't hurt. [ I ordered 12 pairs of the sonic frontiers rca's. I specified solder type - I realized after I received my order that someone else had posted and recommended the "tiffany" style. These are actually modeled after the WBT locking rca's. They look really nice and were only $10 a pair. Here's the question - on the positive "nubbin" it has a set screw. I called them and they told me that I did get the right one - there is no difference between the two except that the solder type didnt have the set screw in it....just a hole where I guess you would apply the solder. Will I get a better connection from using the set screws (all 12 pairs I received have them) or is solder really necessary in this case? If solder is not a need now, it certainly would reduce the assembly time, and would be easier as well add a shield later if needed. ] You can use the set screw IF you have the means to tighten it very firmly, and then I would use it only on the soilid wire, which means reversing what I said just above here. Remember, using the 18 gauge 89248 as the ground side is not that important, and in your case, using it for the set screw is the better way. NEVER tin a stranded wire and then try to crimp or use a set screw with it, the tinning will not allow the crimp or the set-screw to funtion properly. You should consider getting the proper screwdriver or tool to tighten the set screws firmly, or the connection will compromise the sound. [ am I right that ersin multicore solder is better? I have paid close attention to posts pertaining to this as well as manufacturer's recs.... ] Yes, Ersin is good stuff. I have used and recommended the Kester 63/37 tin/lead eutectic for years, with the "44" flux, and this is readily available, but the Ersin is also a really good solder, much better than any RS solder, or no-name 'electrical solder' found at the hardware store. Is it the very best? Who can say for sure? Half the time, the flux makes as much difference to the sound as the solder alloy and purity does. [ however - what core size? what is the best place to get it? (it seems that a lot of companies carry the more common ones, but obscure ratios are more difficult) what exact ratio? ] 0.031 to .040 is fine, anything larger gets unwieldy, anything smaller , and you must feed alot of it into the joint, which can be difficult when soldering plugs. Various nationwide electronics distributors carry the major name brand solders, including Newark, etc. [ I dont own a soldering iron....any recommendations for a multipurpose iron that won't set me back too much? I would say that the majority of my use of it will be fiddling with electronics. ] RS # 64-2055 for $10 is dual heat hand held pencil style iron, 15W for Integrated Circuits, and 30W for everything else. You need at least 30-40W for everyday electronics use, and should not use more than about 15W for Integrated Circuit soldering. I would not get a gun style iron, too heavy. [ I have seen co-ax cable rotary strippers....is this something that is necessary? Or is an exacto knife just as good? Most of the strippers are $14-$18...kind of expensive for the limited application I would use it for. ] This ties in with the above question on soldering too: you need to practice on cheapo cable and RCA plugs first, if you have never soldered. I would recommend at least a pair of needle nose pliers, and a pair of medium size cutting diagonals or dykes, and get some el-cheapo coaxial cable and some el cheapo RCS plugs from RS to practice on. Get a small quantity of regular 60/40 electrical solder, and practice making joints with that. You can also practice taking apart the cheap coax with an xacto knife, and get the hang of it, be sure to practice over a surface that you do not mind marring or cutting, burning or scorching! You will be stripping the center core completely out of the cable jacket and shield braid, so you could cut through the jacket, and then slip the braid off, and cut the foil loose, or just cut everything, as a small penetration of the center core is not a big deal. It is very difficult to cut through everything, a good sharp box knife actually works better than an xacto knife will. Once you get the hang of it, instead of ruining the first set of cable,s and having cold solder joints, and ruined RCA plugs, you have half a chance to do OK. If you learn how to solder with the 60/40, then switch to Ersin 62, you should have no problems when it comes time to do the actual good stuff. I realize that you may use the set screws on the RCA, but this is only for the center pin, you will still have to solder the ground connections. See the Tweaks section for comments on solder, and soldering, or use the AA search engine to seek posts about how to solder, I posted specific instructions somewhere here. Jon Risch
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