It's trivially easy to make low-C cables, but other more balanced approaches work much better ime.
With no insulation on the wires?? With low susceptibility? With low dielectric absorption?
Not so trivial.
Steve N.
It's trivially easy to make low-C cables, but other more balanced approaches work much better ime.
What kid of a metric is cutoff? I can hear 1dB of roll-off. See my updated calculation above.
With no insulation on the wires?? With low susceptibility? With low dielectric absorption?
Not so trivial.
Steve N.
What is your numerical threshold in pf/m for "low-C cables"? Probably you and DaveC are referring to different numbers.
You are now multiplying your previously suggested typical output impedance by 20 - an extreme case that seldom happens and using a 2m cable. IMHO it only proves that in extreme situations capacity matters, but not to 99% of people using typical cables.
I have checked many cables and excepting Kubala Sosna, all were bellow 100 pF/meter. Surely I agree with you that manufacturers could supply cable capacitance. They probably choose not to do it because 99% of users would make an erroneous use of it. Evidently professional cable manufacturers supply it - it is almost mandatory for long cables and professionals need it.
That may be the case. Does the OP have electrostatics?
Steve N.
Empirical Audio
I would say 5pF/foot or lower is low enough to perform well in all systems, both RCA and XLR terminated cables.
Steve N.
I don't believe they avoid publishing for that reason. They either don't know how, don't care or don't have the equipment to do it reliably. Very few cable manufacturers include engineers I have found. They run the gamut from race car drivers to insurance salesmen to hobbyists.
I have literally never seen anyone do a computer simulation of different cables and then do the measurements to correlate and then publish it, except me. Show me one.
Steve N.
Thanks, but I do not see any reason why a 5pF/foot cable should perform better than a 30 pF/foot (100 pF/m) in the audio band.
A few years ago we had a thread on cable simulation at WBF, including examples, simulations and measurements. It was inconclusive, no measurement or simulation could show correlation with sound quality, except for clear cases of misuse of cables, or excessive equipment susceptibility.
Where can we find your papers?
Thanks, but I do not see any reason why a 5pF/foot cable should perform better than a 30 pF/foot (100 pF/m) in the audio band.
What amp + speakers?
I am using a LAvardin IT amp - it has, I am told, an unstable output stage that prefers low-capacitance cables. I know LAvardin make cables, but they are in only 3 lengths, and I would prefer cables that are not so obviously system specific - i.e., there may come a stage when I go and get another amplifier (none decided upon as yet - but certainly more powerful).
My speakers are Yamaha NS 1000m's
thanks
Lohan
What threshold is generally regarded as "low" capacitance?
Are Cardas Clear Beyond interconnects low capacitance?
Are MasterBuilt Ultra interconnects low capacitance?
Clear Beyond appear to have the conductors spaced too closely, and maybe even duplicated conductors doubling the capacitance. This is by observation only.
Masterbuilt seems better, just by its size and dielectrics, but it evidently uses 2 twisted pairs.
Again, even well-known manufacturers are not publishing or measuring the capacitance of their cables. Why not? If they understand the physics, they would understand the importance of this.
Steve N.
Steve... Everyone here thinks their system is special and what they've done with it is special and if they're in the industry what they do is also special. Making statements that their system is EXTRA special and denigrating others by attacking their qualifications and whether or not they choose to share measurements is not cool. Evaluating competitors' designs without hands-on comparisons is questionable and even then... it's just plain questionable to do this at all.
I choose not to show measurements because, like many others in the industry (and not just cables), I don't believe they will be interpreted correctly and incorrect assumptions will be made about the way my product sounds. I've tried all sorts of designs and measured them and I don't agree with you about the importance of super-low capacitance.
I'd much rather people actually try out my product at home, in their own system, and compare it to other products they are interested in at their leisure.
With that said I appreciate anyone with deep technical knowledge posting here including yourself.
One potential reason is loading - say you have 5m of the high capacitance cable. That's going to be 500pF, an impedance of j16k @ 20kHz. If you happen to have an opamp driving this with a 2VRMS signal that's a peak current of almost 200uA. Enough to go beyond that opamp's classA region, depending of course on the particular opamp.
Having said that though its not uncommon for a poweramp to have at least 500pF of input capacitance for RF filtration purposes.
It's a lot like the Nyquist criteria. Makes perfect sense, but we all know that brick-wall filters at 30KHz don't sound right. I have some theories on a lot of these things, but nothing proved yet.
Steve N.
What threshold is generally regarded as "low" capacitance?
Are Cardas Clear Beyond interconnects low capacitance?
Are MasterBuilt Ultra interconnects low capacitance?
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