I think DF96 has a point. Shield (screen) does get connected to return path at receiving end in both cases, either twisted or coaxial. In twisted pair case, if the shield is only connected to return conductor at transmitting end, it still indirectly gets connected via return path at receiving end.
I suspect this practice of connecting shield only at one end came from ground loop problems that themselves came from confusion of signal ground (return) and chassis ground.
yes indeed , that is a big problem with single ended connections between boxes on different AC circuits, SMPS, class D, and/or digital noise. There is no common mode rejection, so any electrical potential difference in "grounds" can be impinged on a low level signal. ( ie hum or low signal to noise ratio S/N,). In audio and instrumentation, the Pro's go with differential signals, In audio choice goes to XLR plugs and jacks.
I need a new interconnect for my TT.
The best I have used so far was VDH coax but now, short of money, I am planning to build a new set of cables.
After readind about the pros and cons of coax and twisted pair, I am wondering if it is a good idea to twist two coax cables, use the inner wires for signal and return and connect both shields only on the input side.
This way, both signal and return wires will have it's shield and they will be twisted.
Please let me know your opinions.
The best I have used so far was VDH coax but now, short of money, I am planning to build a new set of cables.
After readind about the pros and cons of coax and twisted pair, I am wondering if it is a good idea to twist two coax cables, use the inner wires for signal and return and connect both shields only on the input side.
This way, both signal and return wires will have it's shield and they will be twisted.
Please let me know your opinions.
You will lose most of the benefit of twisting, as the two inners will be spaced apart. About the only benefit of your idea is that the capacitance will be half that of a single coax - but that is not normally an issue with a TT interconnect, as sometimes extra capacitance is needed.
Twisted pair within a single shield may be better.
Twisted pair within a single shield may be better.
You might not get much interference rejection; that is what you will lose. Simple coax would be better. Shielded twisted pair better still.
Your idea would work in a situation where low capacitance was the aim, and interference was not an issue. Pickup catridges are not this situation, so you are solving the wrong problem.
Your idea would work in a situation where low capacitance was the aim, and interference was not an issue. Pickup catridges are not this situation, so you are solving the wrong problem.
RC
I have made some Audioquest type DBS style 36 and 72 volt interconnects with and without single ended shields, and overall the shielded single ended for phono was the quietest way on my system.
Not much noticable noise or hum either way between pre and power connections with the same cables.
Regards
David
I have made some Audioquest type DBS style 36 and 72 volt interconnects with and without single ended shields, and overall the shielded single ended for phono was the quietest way on my system.
Not much noticable noise or hum either way between pre and power connections with the same cables.
Regards
David
So what I need is to try to eliminate capacitive coupling of hum using shielded cable..... my build does it very well, already tried it with good results between the TT cart and the riaa amp..... now about it's subjective sound is another story.... it just does not present highs the way the VDH cables do.
Is there many quality difference between Amphenol, Canare, Neutrik or BNC's from other manufactures?
What are the criteria for verifying XLR connector’s quality? Do Amphenol and Neutrik meet the criteria?
Suppose two different arrangements for balanced differential connections: 1 - four BNC 75 connectors with four coaxial cables; or, 2 - two twisted pair shielded cables with two XLR connectors.
Are they equivalent? Is the first arrangement acceptable?
Connectors from reputable manufacturers will be the correct dimensions and will mate with those from other reputable manufacturers. Dodgy ones may not.
I don't know what you mean by a balanced differential connection if it needs so many connectors. One XLR (balanced) or one BNC (unbalanced) per audio channel is all that is needed.
I don't know what you mean by a balanced differential connection if it needs so many connectors. One XLR (balanced) or one BNC (unbalanced) per audio channel is all that is needed.
"balanced" in your context means, balanced impedance connection.
It's the impedances that must be balanced.
The two wire connection is simply that, the wires connect the balanced impedance output to the balanced impedance input.
On it's route the two wire connection must pick up least interference. This is where Marce's
It's the impedances that must be balanced.
The two wire connection is simply that, the wires connect the balanced impedance output to the balanced impedance input.
On it's route the two wire connection must pick up least interference. This is where Marce's
become VERY important.
You can use two coax's as a balanced interconnect.
From Henry W. Ott
Attachments
Just a general note:
Except that the physical paring can never be exact. It is impossible. It's the creation of a serious and audible problem, to deal with a problem that almost never occurs in the world of home audio.
So you end up with transient function issues. An Exacerbation, a false emphasis, an inserted and injected grunge in micro transient function.
Which people, or more tellingly, the human hearing mechanism can and generally does mistake for detail information.
Twisted pair balanced signal transfer, in home audio, or anywhere else, for that matter, is totally off the rails. It has no place.
It was the wrong hammer for an incorrectly conceived problem, in the first place.
It's well past time to see it for what it is, and just drop it ...and walk away.
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