Thanks a lot, all of you. I got enough inputs and food for thought to last me the next few chapters of my DIY journey.
For now, I've decided to use the Belden 8451 shielded cable. I would have liked to use the 8450 a bit more (solid core), but Parts Express was selling the 8451 so I just went for it. Thanks again.
For now, I've decided to use the Belden 8451 shielded cable. I would have liked to use the 8450 a bit more (solid core), but Parts Express was selling the 8451 so I just went for it. Thanks again.
Old scart cables can yield excellent shielded cable. I've just ripped one down and got 6 different coloured copper core, nice copper shield individual cable.
Andy.
Andy.
Wow, great idea. Never thought of that. Will keep it in mind whenever I need multi-conductor shielded cable.
Sorry that I will speak not about shielded cables, but I want to add my humble experience: I started to use twisted pair instead of shielded cables, and a problem with "witch cable to choose" has gone.
I just take usual 0.22-0.25-0.35 mm2 wire, and twist it by myself. It is very flexible, and good enough for my measurement instruments (including low-distortion oscillators, amplifiers, etc).
Here is an example:
I just take usual 0.22-0.25-0.35 mm2 wire, and twist it by myself. It is very flexible, and good enough for my measurement instruments (including low-distortion oscillators, amplifiers, etc).
Here is an example:
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But the shielded cables we've been mentioning here are twisted too. Is your twists per inch more than the normal shielded cable figures?
I don't know, it's hard to find good enough for me twisted shielded flexible cable (somewere in my area). It's very rare, I started to see something like I need only last years. I have one or two examples, but I haven't taked it apart intentionally, and that twists I see in them - they are less twisted than I do, and they have less square milimeters wires (so they are not durable - 0.10-0.20 mm2). If wires are thick (tought) enough for me ( >0.25 mm2) then cable (with shield and outer isolation) becomes too thick and less flexible for inner wiring - not suitable.
The price for that cables (which are almost ok, but not 100% ok for me) is an order larger then just hand-made 0.25-0.35 mm2 twisted wire.
So, from all points of view I have chosen to twist wires by myself. Shield doesn't help much if wires are twisted good (6 dB max in theory).
The price for that cables (which are almost ok, but not 100% ok for me) is an order larger then just hand-made 0.25-0.35 mm2 twisted wire.
So, from all points of view I have chosen to twist wires by myself. Shield doesn't help much if wires are twisted good (6 dB max in theory).
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Understood.
Yes, I can agree with one point: I too have seen shielded twisted 2-conductor cables which are twisted sparsely.
UTP cables (for Ethernet) have very tight twists, but it's hard to find shielded Ethernet cables where I live. Since you seem to like unshielded cable, maybe you can check out UTP cables?
Yes, I can agree with one point: I too have seen shielded twisted 2-conductor cables which are twisted sparsely.
UTP cables (for Ethernet) have very tight twists, but it's hard to find shielded Ethernet cables where I live. Since you seem to like unshielded cable, maybe you can check out UTP cables?
It isn't suitable for me to use UTP/FTP. Cheap UTP - is bad, good UTP - is expensive - I can twist two wires much cheaper. I just don't like to buy expensive cable, and take it apart, and it takes time too.
Sorry about the naive question, newbie here. I don't seem to understand if y'all are talking per channel or per channel pair.
For an unbalanced stereo connection from pot to jack, should I use a shielded twisted pair connecting the two wires to L and R signals, and the shield to common?
Or: two shielded twisted pairs, connecting one wire to each signal and ground, and the shield to the chassis, as shown in https://www.nutwooduk.co.uk/archive/keitharmstrong/design_techniques2.html#_Cable_segregation_and ?
Or, alternatively, a 3-wire + shield, connecting 2 wires to L and R signals, the third to common, and the shield to the chassis?
For an unbalanced stereo connection from pot to jack, should I use a shielded twisted pair connecting the two wires to L and R signals, and the shield to common?
Or: two shielded twisted pairs, connecting one wire to each signal and ground, and the shield to the chassis, as shown in https://www.nutwooduk.co.uk/archive/keitharmstrong/design_techniques2.html#_Cable_segregation_and ?
Or, alternatively, a 3-wire + shield, connecting 2 wires to L and R signals, the third to common, and the shield to the chassis?
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Should the end of the coax shield farthest from the jack be connected to the signal reference? If it is, would interference on the external cable contaminate the signal reference? I thought this was the pin 1 problem, isn't it? Or should it be left unconnected? (is this what other posts meant by floating shield?)
Credit Belden, they did the experiment. They supplied some high end audio DIY hobbyist with different samples of their cables and wire. These hobbyist were of the stripe that says cables have (for the lack of a better term) polarity. Example: Say you have a wire marked "A" at one end and the other end marked "B". You make connection with "A" at a source end and the "B" at the destination end. If you were to reverse the "polarity", "B" is at the source end and "A" is at the destination end. The directional wire hypothesis says these two "different" directions will alter the sound of your audio device.
Belden marked and recorded the cables with the "direction" of the cable and wire. The cables were marked such that the DIY builder could not discern a given wire or cable "direction." The users reported back with the direction they ended up using for a given wire sample.
Bottom line, the directional cable users failed. There was no evidence that they installed the wires and cables in a consistent orientation. IOW they got the cable polarity thing right about half the time.
If the chassis RCA connector has metal-to-metal contact with the chassis, then the shield should be attached there.
If there is a plastic insulator ring, then the shield should be attached to the audio circuit common.