@jea48
Not to speak for George, but speaking for myself, yes, in some cases your ears will detect a difference, such as loss of dynamics or non-repeatable distortion. When you investigate with a 'scope, you will find high frequency trash being amplified along with the signal, which will compete for power allocation within the amp (causing loss of dynamics), or it may beat against the signal (causing distortion). Thus we have an aural effect which can be easily measured.
This method of connection (shield to the insensitive end) has been used in pro audio since Cain first cryo'd Able's tubes. |
That's in addition to the obvious - if it hums, it's a ground loop. Also measurable. |
@jea48
Hello Jea.
To answer your question: I was having a lot of trouble with my system about 20 years ago, when I moved into a new neighbourhood, perfect in every way but RF. I tried a shotgun approach, which worked, but I don't remember isolating this particular variable and testing it by itself. But the theory is sound, which is why it was one of the things in that shotgun.
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I should add that a shotgun approach is also useful in that a number of measures, individually inaudible, can sum to a clear improvement. |
@cleeds
If by "insensitive end" you mean the amplifier end - as George stated - then you are completely confused.
I don’t think that I’m confused at all.
First, we’re talking here about single-ended connections. Pro-audio uses balanced connections.
Quite true - unless they have to connect godless consumer gear. In which case they use balanced cabling differently connected: positive wire, negative wire, shield, instead of positive wire and shield. The negative wire of the balanced cable does the the duty of the unbalanced coax shield. Which leaves the balanced shield. If it’s connected at both ends, you have a ground loop and a potential problem. So it’s connected at one end.
Second, the purpose of the extra shield is to minimize noise. One way to do that is to have all grounds at the same potential.
But that is already achieved with the negative wire of the balanced line.
To best achieve that, you need to tie all the shields together at one common point.
Not so. The shields can get in the way in a careless installation. You need to avoid ground loops.
What common point do all components in a system share? The source, of course.
Not from where I sit. Cartridge pins being the common point? Don’t think so.
My system is a bit unusual, I’ll admit, but here’s how I did it. I built a power supply for all 6 of the amps, with a central ground. The phono/pre is powered by batteries, and it floats. Everything else is on isolation transformers. There is exactly one ground point in the system: in the power supply. Interconnects consist of balanced cabling connected single ended, as I have indicated. My system is BLACK.
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I think that I could have said that more clearly. Instead of
"But that is already achieved by the negative wire of the balanced line"
perhaps I should have said,
"But that is already achieved by the negative wire of the 2 wire / 1 shield line."
Does that make sense to you now?
As to my remark about the pins of a phono cartridge, it was you who brought up the notion of source. If you now wish to recant, that's fine with me.
As for my knowing something that no one else understands, why so aggressive Cleeds? Why not discuss things on their merits?
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@nonoise
Yes, I am versed in statistics. The chances of many people believing something cannot be estimated without reference to either a lot more data (such as how many don't believe it), or simplifying assumptions.
I would point out that lots of people believe things without foundation. See especially the Nazi's strategy of The Big Lie, and note how it has been broadly applied in the modern world.
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@nonoise
My response was to your direct question about statistics.
As for your point about first hand observation, statistics has something to say about that too. It is very tempting to think that one is experimenting when one is just fiddling. Unfortunately, experimenting can be quite hard, especially when dealing with psychological phenomena, such as sensory perception. To do that right, one needs a lot of sophistication: mathematical, statistical, and psychological.
And then, after all that sophistication, one can still get it wrong, which is why professionals use peer review.
By all means, trust your ears. It's your system and your money. |
@ivan_nosnibor
Ivan, I was simply pointing out the difficulty of conducting a valid experiment. There are too many ways for the mind to trick a putative experimenter. The scientific method is capable of controlling these to a large extent.
Should one choose to ignore the scientific method, alternative explanations of any 'result' are obvious. As I tried to point out, I don't care if people wrap their cables in thousand dollar bills, it's their money. But I put no credence in any 'result' which offers neither theoretical justification nor valid experiment.
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@ivan_nosnibor
No problem, Ivan. No offence taken. We all rant from time to time.
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@herman
Thanks for your input, with which I completely agree, except for "the movement of electrons is the cause when it is the effect". In my view, the two are dual, in the mathematical sense.
I guess that comment is intended for you and Al and Ralph. |
@herman
Thank you for your considered response. |
@jea48
"Just a guess no one has experiment using bare uninsulated wires for ICs or speaker cables."
I have. My ESL's are each powered by a mono block. Each ESL has a step up transformer, which must be resistor tuned. I put the resistor externally; more precisely, I connected mono block to speaker with nichrome wire, uninsulated so that it can dissipate heat. Thus the surrounding air is the dielectric.
For safety, I now cover half of each speaker wire with a loose covering of teflon, so that they cannot arc. Virtually no contact between conductor and dielectric, so no difference in sound. |
@jea48
Yes also to IC's.
Further to the above, I forgot that about 20 years ago, when I saw IC costs going stratospheric, I decided to do an experiment.
I built a cabinet for ARC SP10 pre-amp and Nakamichi CR7, which was a Faraday cage. I then noted that, at line levels, capacitance was the enemy, not inductance, so I found some very pure 4 nines silver 24 AWG and had it gold plated.
I drilled holes in the bulkhead between the ARC and the Nak which were 2" apart and threaded bare wires through them, and then protected the wires with 0.375 teflon tubing, which touched the wires scarcely at all. Thus, compared to conventional co-ax of whatever manufacture, dielectric absorption was near zero, as was capacitance. Cables were 26 inches and terminated with ETI RCA's.
I was then in a position to conduct a single-blind experiment of theoretically optimal cables compared to Canare Starquad. An expert test subject (my long suffering wife) was unable to detect the difference reliably. Of less interest, because I was not a blind subject, I was also unable to hear the difference.
This is NOT definitive because the subject was not required to make many, many repeated observations for statistical analysis. But the point was clear: there ARE things that yield readily detectable differences, like turntables, tonearms, cartridges, SUT's, tubes, pre-amp topology, power supplies, capacitors, resistors, amplifier topology, and speakers.
So the latter is where I spend my money.
So, Jea, just for the record, the test has been done. |
@jea48
No, Jea, I didn’t read it - I skimmed a bit, and what little I did read seems to be perfectly covered by Al.
Thanks Al. Somebody's got to speak up for science. |
@jea48
Solid. They came off the spool and went to the plating company. No, I did not reverse them. I did not then, nor do I now, expect there to be a perceptible difference.
I no longer spend much time on interconnects, for the reasons stated. |
