That definitely makes sense, just never really thought about the possibility of the amplifier actually amplifying RF leaking in from the output.
Thanks once again - always something new to think about here
Thanks for the info fellas! This cable is going to an 8-wire going to banana plugs :)
You'll undoubtedly find it a lot easier to ignore the shield and use the 2 wire ground approach.
I've heard someone here mention once about connecting the shield to ground at the source as well, but I've never done this, and am not sure exactly what benefit that would provide.
Grounding the shield at the source end provides some RF blocking, at the expense of increased cable capacitance.
It is somewhat hit or miss, although I am biased towards doing it.
The "hit" is: Why bother with RF when "all" we care about is the audio-band? Simple - your amp may care about RF. If your amp is using all of its energy to amplify RF, what does it have left for audio?
The "miss" is: the increased parallel capacitance may muck up the stability of some amps.
Interesting. I knew RF factored in here, but didn't really know the 'plus / minus' side of things, nor that the amp itself made a difference in terms of deciding to terminate the shielding at the source.
I'm not quite sure what you mean by the statement " If your amp is using all of its energy to amplify RF, what does it have left for audio? "
Thanks for the info, I'll have to look into all of this further!
RF can get into the amp through the outputs.
When you look at the feedback loop, with a nice cap across the feedback resistor, there is a path from the output of the amp straight to the input - at RF anyways. At that point the RF gets amplified by the open loop gain of the amp.
Without this cap the amp may not run stable at all! So your kind of in a bind.
Alternate solutions are to put a ferrite bead on the cable, or add some output resistance outside of the feedback loop, but people freak out like what when you do that.
Thanks for all the replies. Very informative. I wasn't quite sure as to how to handle the shielding wire as I had only been making cables for my iems using individual wires so far, and only just started working with premade mogami. Had no idea how the shield was going to affect things, but now I have a clearer picture.
Quick question for anyone who knows heir audio's UIEMs:
I just made a cable for myself for my set of 4.Ais, and was just wondering about polarity - Which hole is signal, and which is ground?
Not entirely understanding phase, I guess it's just good that I just treat both the left and right channels the same?
Basically I could use any of your suggestions here.