Measurements aside the 1980's Pooge ( Progressive Optimization Of Generic Equipmentt) articles in Audio Amateur by Walt Jung and Dick Marsh were some of the most influential of the time. They changed electrolytic and ceramic capacitors for film ones (and DC servos later on), metal film resistors, and better wire and connectors (non -ferrous being a later recommendation).
and better power supplies - soft recovery diodes, bigger filter caps, lower noise regulators, RC or CLC pre filtering etc.
The improvement in almost any brand's pre-amps, power amps, dacs, and speakers - basically the entire system that were upgraded following the POOGE guidelines was nothing sort of spectacular and set the standard for passive component selection going forward. Passive components, despite their distortion being below the distortion levels of the active components, are audible - so what other mechanism besides distortion is audible ?
and better power supplies - soft recovery diodes, bigger filter caps, lower noise regulators, RC or CLC pre filtering etc.
The improvement in almost any brand's pre-amps, power amps, dacs, and speakers - basically the entire system that were upgraded following the POOGE guidelines was nothing sort of spectacular and set the standard for passive component selection going forward. Passive components, despite their distortion being below the distortion levels of the active components, are audible - so what other mechanism besides distortion is audible ?
Capacitors work by moving charge in/out of the plates. In addition, charge moves within the dielectric - but this is not bulk movement of charge but local displacement of charge; if you like, a molecule gets a positive charge at one end and a negative charge at the other, with no charge hopping between molecules. This causes the relative permittivity to increase above one. In many dielectrics this is approximately linear, especially low permittivity ones. High permittivity dielectrics are often non-linear. The explanation for this comes from solid state physics which I forgot many years ago.jan.didden said:
If the charge responds immediately to the applied field then no DA occurs. If the charge takes a while to respond and does it like a decaying exponential then DA occurs. So there are two effects:
1. how much does the dielectric charge move - this can be little or much, and can be linear or not.
2. how fast does it move - this can be fast or slow.
Ultimately both depend on the dielectric substance but the fact that DA seems poorly correlated with nonlinearity suggests that DA does not cause nonlinearity.
My understanding is that DA is essentially a slow phenomenon, so can't affect audio. A faster version of it might show as dielectric loss, but that would merely insert or affect filters.
Oh, charge can move into the dielectric. I was just clarifying that that's not how a capacitor works ideally. Your original statement seemed to be saying that a capacitor and DA worked by the same mechanism.
se
That's why the Kundert piece is so informative.
An externally hosted image should be here but it was not working when we last tested it.
se
I wasn't saying capacitors needed dipoles to work. Where's this coming from? SY said dipoles can give the impression of charge moving, and Jan was wondering about what he meant.
se
I didn't find that to be true, in fact in the end I figured upping the bias to 50W class A and doing a proper grounding scheme, on each channel accounted for 99% of the improvement. I did start with amps that had (I forgot what type) a film cap on the input but replacing it with PP and adding 10uF film across the 10000uF PS caps was not audible to me. I did rewire them with handmade litz wire but did not try w/wo a star ground so nothing can be concluded from that.
I guess Victor Campos was right.
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Sorry, I thought there was lingering confusion in some parts on displacement current.
That's important to know,I guess that makes it clear to me that the 'normal' workings of a cap and DA can have different, not necessarily related, effects.
About re-alignment, sort of, this is what Bateman says, is that what you mean:
"What’s a non-polar dielectric? I should clarify my use of polar and non-polar dielectric, which should not be confused with Aluminium Electrolytic, often also called polar and non-polar. With the electrolytic capacitors
we are simply describing whether they need a unipolar bias voltage or can be used with either polarity of bias. With plastic film capacitors these terms describe a quite different, molecular level, dielectric behaviour. A non-polar dielectric has a simple, short, molecular structure in which the nucleus is surrounded by its electron cloud. A polar dielectric is a long and unbalanced molecule so has a polar vector caused by an excess of unbalanced electrons. Perhaps the most common, simple example, is water, or H2O. Common plastic film capacitor dielectrics have an exceptionally long molecular chain, especially so for metallised PET. The polar moment caused by this unbalanced molecular structure results in the dielectric absorption, as well as the level of second harmonic distortion I measured."
(Bold mine)
Jan
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My 'theory' (in other words, IMO) about some parts replaced which had low 'distortion'.... ... there seems to be some forgetfulness that we dont replace one single component part in a system. Going from all cc (like I showed of a Dynaco tube preamp) to all mf resistors is what we typically would do and dozens changed thru out the entire system on both channels..... THAT is when even small amounts begin to make a larger difference.
Same might apply to one single cap or one opamp somewhere. The differences show more easily when a lot of them are changed. And, generally, that is what we have done over time..... all are upgraded. Does it measure or sound different? The total affect is always greater.
Typically, without servo in audio circuits, we have 8 polar caps per channel (LP). Still that way in many low-mid priced receivers and amps and add in Cd players.... one on each in/out/and gain.
There is a necessary place for individual component testing, of course, and there is also a place to see what accumulated affect using several (dozens?) gizmo's will have as well. What would be the best dut topology for testing several cap at same time to reasonably represent the total circuit behavior of all the cap??
THx-RNMarsh
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IMO:
Easiest to hear: frequency response changes (or "linear distortions" if you like). Low-Q resonances are especially audible, high-Q ones require signal energy close in frequency to the peak or dip, with the peak usually more audible.
Fairly easy to hear with low-level program material: crossover distortion near the origin, amounting to a severe loss of gain at those low levels. Hard to hear with normal level program material.
Fairly easy to hear if there is a lot of it: clipping distortion.
More difficult: IM distortion, unless it is terrible, or resulting from a pathological pair of adjacent tones and absence of masking (example, the 1kHz difference from 19kHz and 20kHz).
Much more difficult: single-frequency-signal harmonic distortions from smooth nonlinearities. They sound like timbral shifts and small level differences.
The other thing: when B follows A, all other things equal, B is preferred---unless B is just awful. If B is louder than A, B is preferred---as SY described a while back, from his experience, even when the small difference is not perceived as a level difference.
POOGE may have been a noble effort, and undoubtedly lots of fun, but I think suffered significantly from the creator effect. How can one not like one's progeny---unless they are just awful?
Yeah, this is the subject of my upcoming LTE. It's wrong. Bateman really should have consulted a materials scientist before writing this.
I'm sure it will be appreciated. My menu French is pretty adequate and I still remember enough to ask directions. My last time there, I was with Jan, who is quite fluent. It was amusing because when we visited a winemaker, Jan stumbled on agricultural and winemaking terms. Since I knew them (but not the sort of normal conversation at which Jan excels), it made me look smarter than I actually am.
I recommend Jan to anyone who needs a straight man.
Sorry, but I think something is wrong there: for a small molecule, like H2O, a single unbalanced electron orbital will have a heavy impact on polarity, but for a long polymer chain, imbalances will not simply accumulate: at the very worst, they might stay the same proportionally, but normally they will either tend asymptotically to some (lower) value, or vanish almost completely.
High molecular weight PS is among the best dielectrics, yet its chain length is very high compared to water (a poor dielectric, even when perfectly pure).
Another problem is the alleged presence of H2: if the material is anisotropic and in the absence of external bias, imposed or intrinsic, there is no reason for such a distortion: non-linearities will always be of odd order, because of the inherent symmetry.
Not true. It depends on the RC time constant of the external circuit on how much DA recovery voltage occures and the period of its discharge. The charge and discharge times or period if you prefer develop higher DA recovery voltage if the external Z is high. The longer period of the signal will allow more 'soakage' to occure.... so in that regard the longer signal periods will show the higher Vda. But if the rep rate is increased the time to charge and discharge becomes smaller and the corresponding DA recovery voltage will become lower in the external circuit. Periods well within audio freq periods/cycles show it.
THx-RNMarsh
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Are you sure this is DA, how did you reach this conclusion? Except for some extreme source impedances in the MOhm range, DA should not depend on the external circuit.
http://patriotgaming.com/manuals/gaming_monitors/sencore_instruments/LC103/TT105-3759.pdf
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