Parasitic inductance from long leads is reported on many forums, maybe even this one?
e.g. What is Stray Inductance? I would rather 'hedge my bets' with this learning website, than your opinion.
Your derisory comment of me meddling I find insulting at the very least! If you had seen the state of the dry joints and inadequate (or copious) solder applications anyone would feel the need to correct those joints with silver solder applied @ the correct temperature etc.
I once talked about replacing small OEM caps with large boutique caps (e.g. mundorf) that didn't fit the allocated place and would have needed to be raised or sided from the PCB with long leads and there was a barrage of replies stating the parasitic inductance scenario would need effective insulation against the inductance? Can't remember which website/forum that was. So I would say definitely needs insulation of some sort?
True, the inductance remains the same but effective insulation prevents that inductance from reaching other components.
I think it was "the art of sound" forum were they said that under no circumstances should you install large audiophile caps with long leads due to the parasitic inductance; but if you do - (AT LEAST) please ensure you use effective inductance materials on those long leads! Are you saying that they are totally incorrect and they don't know what they are talking about on that forum please? YES/NO?
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My comment about meddling was a poor attempt at humour. Sorry for offending you.
Insulation does not affect inductance. It does not affect how the magnetic field links with nearby circuit loops. Insulation makes no difference at all to magnetic fields, so you can ignore advice from anyone who suggest otherwise. The main benefit of insulating component leads is that it makes probe slips during faultfinding less harmful. It may also slightly (very very slightly) increase stray capacitance, but this is unlikely to be of any consequence in an audio circuit.
Insulation does not affect inductance. It does not affect how the magnetic field links with nearby circuit loops. Insulation makes no difference at all to magnetic fields, so you can ignore advice from anyone who suggest otherwise. The main benefit of insulating component leads is that it makes probe slips during faultfinding less harmful. It may also slightly (very very slightly) increase stray capacitance, but this is unlikely to be of any consequence in an audio circuit.
I think it was "the art of sound" forum were they said that under no circumstances should you install large audiophile caps with long leads due to the parasitic inductance/Capacitance leaks; but if you do - (AT LEAST) please ensure you use effective inductance materials on those long leads! Are you saying that they are totally incorrect and they don't know what they are talking about on that forum please? YES/NO?
I think it was "the art of sound" forum were they said that under no circumstances should you install large audiophile caps with long leads due to the parasitic inductance/Capacitance leaks; but if you do - (AT LEAST) please ensure you use effective inductance materials on those long leads! Are you saying that they are totally incorrect and they don't know what they are talking about on that forum please? YES/NO?
Infact, I think I will publish your comments on my 'art of sound' thread to see how they react to it, as I am determined to get to the bottom of this issue once and for all!!
Therefore, please be careful how you respond as this could potentially spark a inter-forum war!! BUT if you really and truly believe in your own words as 'the last word and authority' on the subject this will not pose any significant problem to you personally? If you now elect to stay silent; your silence speaks volumes, and I therefore rest my case!
Long leads add inductance, which may or may not matter depending on circuit details. Insulating those leads makes absolutely no difference whatsoever. There is no substance I am aware of which has relative permeability below 1, so nothing can be added to reduce inductance. To reduce inductance you need to reduce loop area, which means shorter leads and leads which are closer together. You may need to insulate to allow leads to be brought closer together without the risk of shorting, but it is the closeness not the insulation which reduces inductance.
I don't know what is meant by 'capacitance leaks'. Long leads could reduce stray capacitance, by allowing the component to be further away from other components.
I don't know what is meant by 'capacitance leaks'. Long leads could reduce stray capacitance, by allowing the component to be further away from other components.
Experience has taught me that comments allegedly made by other people may be misreported or misunderstood or taken out of context. Hence I am cautious about directly commenting on what others are said to have said. I trust any such other people will be equally cautious about commenting on a second-hand report on what I have allegedly said.thedoc735 said:
I have no interest in 'forum wars', only truth. The reason I am on this forum is that a sufficiently high proportion of people here are also interested in truth. I have never claimed to be "the last word and authority" on any subject. I merely report what I believe to be true, and in most cases it can be checked in any good textbook or verified with anyone else with sufficient subject knowledge. If others disagree they can either correct me (if I am wrong), learn from me (if they wish), or continue in their error.
You seem to be getting this all out of proportion in your rather strange remarks about interpreting "silence"!
You see, that is why I am cautious about what others are said to have said. I did not know whether they used the phrase 'capacitance leak' or you were incorrectly reporting them.thedoc735 said:
you are incorrect! ~ I would not comment on other peoples' remarks at all, I would "copy & paste" others comments "AS IS" i.e. I would not 'interpret', 'edit' or 'comment' on what others have said! (I would always faithfully copy it).
This appears to be a report by you of what others have said. Are you now saying that these are your own comments, and not to be interpreted in any way as a report of what others have said? The apparent reference to another forum should not be interpreted as a reference to another forum?thedoc735 said:
Please make up your mind. Ignore what others say, or report in your own words what others say, or directly quote what others say. Don't do one then claim that you were doing something different.
Interesting how no one on any forums actually gives a reference to any text book, paragraph, phrase or page in support of their claims! It is always: "it can be checked in any good textbook", but NO ONE EVER GIVES an example in support of their claim? Strange! Very vague, no back up, no support, no evidence! Same on all experts, on all forums! Surely people can back up their claim as I once did many years ago regarding ZX1 http://www.team-zx1.com/ ...engine and gear box lubrication. After that, 'the decenters' went quiet. I took it all the way to the company for official reports & records!!
Thank you! I will see if I can find the comments "AS IS" later on as this was some time ago. Thank you for your patience and thank you for your replies to this thread, very grateful. 🙂
First, these are not "claims" but facts.thedoc735 said:
Second, there are several reasons why references are not usually given:
1. The people needing them almost certainly don't have any textbooks. Even when they have it may well be a different book from those owned by the "expert".
2. It may take time to find an appropriate page/chapter. This is a discussion forum, not a 'pro bono' teaching resource. It is DIY audio; DIY includes thinking and researching, not just building.
3. Someone who is really confused may find that a good texbook goes over his head, while a simpler book makes the same mistake that he is making - or at least is unclear.
There is a general problem which frequently emerges on here and other forums: what appears to a newbie to be a debate between two schools of thought is actually a (failed) attempt at teaching the basics to someone whose confidence is not backed up by knowledge. To have a debate you need two people with similar knowledge but different opinions; true debates do occur on here and I have learnt from them.
So, when I say that insulation does not reduce magnetic properties like stray inductance I do not think it necessary to provide 'proof' of this fact. It is up to you to check that normal substances do not have relative permeability below 1, and most insulators have relative permeability approximately equal to 1, or accept what I say.
That gives an informal explanation of stray/parasitic inductance, but it doesn't tell you how to calculate the inductance value of a piece of wire, or knowing the inductance value, how to calculate the resulting inductive reactance at a certain frequency in a circuit. I've seen high-power FETs with lead inductance stated on the datasheet, but not for other parts (for the retentive folks, yes there may be other parts that state lead inductance on the datasheet, I just don't recall seeing them).
The textbook you need to study to calculate these things is titled "AC Circuits Analysis" by whatever author(s) are listed.
For effective "inductance" [magnetic] shielding, and presuming this is actually needed to prevent the signals going through these long leads from affecting other components, the appropriate material to used is mu-metal.
thedoc735 said:
I find your argument a little pedantic regarding exact wording! Surely an idea can be expressed in alternative words but retain the meaning? For example: is not "the boy has a blue candle" the same as "the candle that the boy holds is blue" ?
I do know that insulation will not affect magnetism! (except for alloy/lead and such like shielding).
You have given a standard reply to avoid quoting a text book i.e.
"1. The people needing them almost certainly don't have any textbooks. Even when they have it may well be a different book from those owned by the "expert".
2. It may take time to find an appropriate page/chapter. This is a discussion forum, not a 'pro bono' teaching resource. It is DIY audio; DIY includes thinking and researching, not just building.
3. Someone who is really confused may find that a good texbook goes over his head, while a simpler book makes the same mistake that he is making - or at least is unclear."
....heard it all before. And before you ask, YES I HAVE quoted textbooks, chapter and verse in the past to back up what I said, BECAUSE I DID feel it was necessary to take the time and trouble to support the facts in any given scenario, this makes me highly unusual because everyone else appears to be like you, with your attitude to help. i.e. go find out yourself, this is for discussions ONLY - and not tuition! "BUT!" - I didn't ask for tuition I merely reported what I had done to the DAC at the current time i.e. fixing other peoples botched work and insulating long leads to make probe slippage less harmful and "it may also DE-crease stray capacitance" OR parasitic inductance.
You have given a standard reply to avoid quoting a text book i.e.
"1. The people needing them almost certainly don't have any textbooks. Even when they have it may well be a different book from those owned by the "expert".
2. It may take time to find an appropriate page/chapter. This is a discussion forum, not a 'pro bono' teaching resource. It is DIY audio; DIY includes thinking and researching, not just building.
3. Someone who is really confused may find that a good texbook goes over his head, while a simpler book makes the same mistake that he is making - or at least is unclear."
....heard it all before. And before you ask, YES I HAVE quoted textbooks, chapter and verse in the past to back up what I said, BECAUSE I DID feel it was necessary to take the time and trouble to support the facts in any given scenario, this makes me highly unusual because everyone else appears to be like you, with your attitude to help. i.e. go find out yourself, this is for discussions ONLY - and not tuition! "BUT!" - I didn't ask for tuition I merely reported what I had done to the DAC at the current time i.e. fixing other peoples botched work and insulating long leads to make probe slippage less harmful and "it may also DE-crease stray capacitance" OR parasitic inductance.
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I know the webpage doesn't tell you how to calculate the inductance value of a piece of wire etc. & that it is a general explanation only but I basically find it useful. Unlike DF96 I don't attempt to discredit every single website and book that I don't personally happen to believe in or agree with!
Yes I will be using mu-metal, as well as copper shielding. (sandwiched between heat shrink).
I know this will be interpreted as 'OTT', but that's my choice, no harm done in this hobby. Maybe just somewhat palliative?
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are you sure you have got this right?
Again are you sure?
Adding insulation between two conducting materials INcreases capacitance
and has no effect on the inductance.
Increasing the loop area of the circuit increases the inductance.
Perhaps, but 'capacitance leak' does not mean the same as 'stray capacitance'. You appeared to be reporting what was said by others, but then denied this. Please make up your mind. It is unfortunate that in quoting yourself you have now edited out this error (i.e. you are now misquoting yourself!), which may mislead others following this discussion.thedoc735 said:
On discussion forums all we have is text (plus a few pictures). The only way we can tell what someone is thinking is to read what they say. If they say meaningless things then this may be a sign that they are having meaningless thoughts. You were apparently reporting what others had said, and in doing so you used the meaningless term 'capacitance leak'. If this is what they said then this shows they don't know what they are talking about, which is why I queried it. At that point I didn't know whether this was them talking nonsense, or you misreporting them. It matters because I did not want to form a false view of their competence based on your misreporting.
Good.
Belief is not the issue. Facts is the issue. I only "discredit" nonsense. It appears you are not yet in a position to form a considered judgment about the reliability of much of what you read, yet you resent the comments of those who can do this.
Mu-metal can provide magnetic shielding, but it won't reduce stray inductance but significantly increase it. This is because mu-metal has high permeability (hence the name). Putting it near a wire will increase inductance but reduce coupling. As it has quite a low saturation threshold it is usually used around the receiving end of unwanted magnetic induction, not the sending end.benb said:
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