Cable Vibration

[3DSonics]

Hi,

Shouldnt adequate insulation, earthing and construction null that? I would be interested to know the magnitude of the effect if it has ever been measured.

Any number of things should any number of things.

As they say:

IN THEORY practice is the same as theory, IN PRACTICE however theory and practice rarely are the same.

Ciao T

 

[anon_bb]

That statement doesnt mean anything! You are obviously picking the wrong theories . Lets see some experimental data then I will swallow it.

 

[3DSonics]

Hi,

Lets see some experimental data then I will swallow it.

Suit yourself. Take 5m Speaker cable. Place it on a normal concrete floor. Measure the capacitance to earth (not between conductors. Now place the cable on upturned polystyrene drink cups so it is kept well clear of the floor and repeat the measurement.

Static (dis) charge is harder to measure and it's effects both in terms of MDI and actual large discharges less predictable. You might want to read the stuff written by Pierre Johannet on such and related topics that is posted in my Yahoo Group Files section (in French I'm afraid).

Ciao T

 

[anon_bb]

What will the magnitude of the difference be and will it affect the signal propagation? I find it hard to credit intially that these affects could be audible or have measureable effect on the signal. I have never heard the cable tick effect I must admit. What is your yahoo group name?

 

[3DSonics]

Hi,

What will the magnitude of the difference be and will it affect the signal propagation?

Measure it. But take account of the fact that many (solid state - high feedback) amplifiers have outputs that can react funny to certain capacitive loads. No doubt you will cide this as bad design and I agree, but it does not make the issues go away.

In addition, as always my point about cables is that certain effects may or may not be present and may or may not have an audible impact depending on a huge raft of contextual condition.

Much of the problems with audio cables stem directly from inapropriate interfaces (single ended or direct coupled "dual, opposite polarity SE" often mistakenly called balanced), the neccesary compromises to achieve "CE" electrical safety, compliance with EMI and other regulations and so on.

So, in any given system any number of effects and issues may be present, absent, audible, below audibility and so on. Hence the cable which in one system ends up making a "night & day" difference (because the previous choice caused serious problems somewhere and these are fixed) may be indistinguishable from bellwire in another system.

I will argue that a truely competently designed piece of gear shows minimal sensitivity to cable quality, mains cables, mains quality and so on and that sensibly priced cables of aproppriate and competent design and construction should be all that is needed. But I have made neither this universe, this world, the people on it nor the rules and whiles they follow, I just live here and observe.

What is your yahoo group name?

Links here:

http://groups.yahoo.com/group/Thunderstone_technical/

The technical Group is for the heavy duty tekki stuff and has the big library with the more or less serious works.

http://groups.yahoo.com/group/Thunderstone_audiophile/

The audiophile group is for nice and shallow audiophile banter, well, in theory (see above for the relation 'twixt theory & practice) anyway.... ;-)

Ciao T

 

[anon_bb]

Thanks!

Sure badly engineered systems could have all sorts of effects. A very nonlinear power amp could exhibit exponential sensitivity to initial conditions ("chaos") such that an infinitessimal change in cable capacitance could cause it to switch into an entirely different regime of operation - indeed some rf amps are purposefully designed that way. The point would be that if a power amp is sensitive to cable vibration in this way then the best solution is throw away the amp and buy a new one rather than sticking the cables up on supports as its design is likely to be seriously flawed in every respect . Same holds true for the other issues. I agree absolutely about the interfaces being of paramount importance.

 

[3DSonics]

Hi,0

The point would be that if a power amp is sensitive to cable vibration in this way then the best solution is throw away the amp and buy a new one rather than sticking the cables up on supports as its design is likely to be seriously flawed in every respect . Same holds true for the other issues.

I agree that this may be the "best" solution, however, to repeat:

"I have made neither this universe, this world, the people on it nor the rules and whiles they follow, I just live here and observe."

And given how much gear is "badly designed" either because the neccesary cost cutting to hit the price point or because of Electrical Safety and other Regs or because of the sheer incompetence of the designer (if you see the majority of PCB layouts in consumer audio gear you realise that that they are usually autorouted with minimal manual intervention and have huge issues with grounding, crosscoupling etc) buying another amp may send you from meatgrinder into the frying pan.

Adding an output matching/isolation transformer (external) and an input transformer (internal) to the existing Amp may be a much better investment as it gives you floating balanced feeds/inputs not referenced to earth/ground and thus considerably reduced all the relevant issues.

Ciao T

 

[anon_bb]

Indeed. However I think a unit regardless regardless of price can be engineered to avoid thess issues. I just think that "cable pylons" are ridiculous and show the state to which the industry has sunk. As you say its like a den of thieves out there!

 

[dunkyboy]

I would imagine, though it looks ridiculous, a handful of polystyrene cups under your cables would most likely be a much cheaper solution than buying a new amp!

Interesting discussion, btw.

Dunc

 

[anon_bb]

Yes it would but the point is that an amp that necessitated that would not be worth owning as its design would likely be compromised on every level. Far better to sell it and buy an amp that is well engineered .

 

[dunkyboy]

<controversial>We'll, if it sounds good, who cares how well engineered it is? Break out the polystyrene cups I say! </controversial>

Dunc

 

[Tenson]

Glass cups, surely, would be better to reduce static!

 

[3DSonics]

Hi,

Glass cups, surely, would be better to reduce static!

Look better too.

The Styrene cups are suggested for one simple reason for measurements. In your Lab/Workshop at ones dayjob there tends to be a ready supply of said cups from coffee machines and/or watercoolers, so getting an end of twin-wire cable and measuring it on the floor and off is easy.

I do not recommend styrene cups at home except possibly liberated from works kitchen to check if elevating cables makes a difference in ones own system.

I would add that in my system I do not elevate speaker cables, I find little benefit, but I exclusively use low Feedback (or no-feedback) Valve Amp's....

Ciao T

 

[anon_bb]

Just use thorstens patented anti-gravity levitation mantra to isolate the cables from ALL outside influences. It is of course an optical illusion brought on by imbibing mystic rhizomes but illusion is allegedly better than reality anyway! ;-).

Perhaps a bake-off is in order to assess the effect of glass v polystyrene versus mere carpet bound cabling in a blind test?