Yes, my point is that in many new designs the passive component selection is quite important as what used to be the limit is no longer!
I've attached some capacitor vibration plots. The electrical excitation was a 9 volt battery. I need to dig for the actual acceleration but figure with just normal baseline vibration the voltage levels will be 45 db down. So all of these parts would cause problems in something as common as a phono preamp!
Attachments
I was going to question Doug Self not specifying the big can at his MC input. I don't use them in the signal path. OTOH I have had quite tap sensitive 1nV preamps that exhibited no problem sitting on the bench with just a soft silicone damping pad.
The problem today is that we have far too many manufacturers in the fray, so selecting the good from the so-so and bad parts is becoming a full time profession.
Furthermore, all this mass production has reduced prices very significantly, both in relative and absolute terms, but unfortunately, all too often at the expense of quality.
Look at modern nominally 1% metal film resistors - tragically too many times, upon measurement, you discover that the "1%" was a drunken joke. As a response to this, what do we have? Super quality, ultra resistors, which cost an arm and a leg and in many cases simply only adhere to their nominal tolerance, only a few really do bring improvement to sound.
Don't even get me started on LEDs - 30 years ago, they were used in part because of their extreme life expectancy, and today? A hell of a lot of Chinese LEDs give up the ghost in less than 2 weeks.
Transistor you all know about - don't swear on the originality of any of them, especially if they are cheap.
So, in fact, in some ways we are worse off today than we were in pre-China days. Yeah, it's a lot cheaper, but it's also a lot less reliable.
Furthermore, all this mass production has reduced prices very significantly, both in relative and absolute terms, but unfortunately, all too often at the expense of quality.
Look at modern nominally 1% metal film resistors - tragically too many times, upon measurement, you discover that the "1%" was a drunken joke. As a response to this, what do we have? Super quality, ultra resistors, which cost an arm and a leg and in many cases simply only adhere to their nominal tolerance, only a few really do bring improvement to sound.
Don't even get me started on LEDs - 30 years ago, they were used in part because of their extreme life expectancy, and today? A hell of a lot of Chinese LEDs give up the ghost in less than 2 weeks.
Transistor you all know about - don't swear on the originality of any of them, especially if they are cheap.
So, in fact, in some ways we are worse off today than we were in pre-China days. Yeah, it's a lot cheaper, but it's also a lot less reliable.
So ... we should now construct audio board shock absorbers? Insert rubber rings before we screw them inside the case?
Holy moly ...
Scott,
You just explained why for some audio preamps magic pads under the unit's feet can actually do something! Yes getting rid of vibration is one solution.
It also turns out capacitors are sensitive to vibration in the direction that impacts the parallel plates the most.
Of course not introducing the problem is a viable solution.
Next thing you know folks will figure out that much of the discussion of audio platitudes is aimed at the wrong issue!
One of the lessons I had to learn in Pro Audio is that folks who can't judge on merit judge on appearance. A 77" tall 19" equipment rack filled with color matched blank panels is a much more impressive sound system than a single shelf mounted box or two. A giant speaker cluster must work better than a bank of small time aligned ones. A $50,000 system must be better than a $10,000 one. (Well that last lesson does benefit me!)
ES
Sorbothane and potting compound.
Anyway, I saw a piece on outsourcing last week saying 40% of the US companies who were outsourcing work to China were considering pulling back. 60% who were in active planing were considering not doing it. Logistics, quality, slave labor is now acting like they want to get paid, and anyone blowing the whistle on corruption winds up in jail. I suspect the reputation for their quality, counter-fitting, intellectual and property theft are turning a few consumers off. They will learn, but they have dug themselves a very deep hole.
Anyway, I saw a piece on outsourcing last week saying 40% of the US companies who were outsourcing work to China were considering pulling back. 60% who were in active planing were considering not doing it. Logistics, quality, slave labor is now acting like they want to get paid, and anyone blowing the whistle on corruption winds up in jail. I suspect the reputation for their quality, counter-fitting, intellectual and property theft are turning a few consumers off. They will learn, but they have dug themselves a very deep hole.
What a fantastic reaction . From reading H C Lin paper PNP was very difficult in early op amps .
Thanks everyone I have been trying to put this story together for years now . As I understand it op-amps were intended to be used as analogue computers with some audio applications . H C Lin says that they were declassified earlier than expected as they did not suit military requirements . As far as I know H C Lin perfected the MOS FET's I favour about 1968 ( I have the patent somewhere ) .
Funny thing about Sid Smith . He used at home tube Marantz No 9 in triode . He said to me maybe one day his transistor designs would be celebrated also . He almost seemed nervous to mention them . He insisted they need capacitor upgrades which he had only recently discovered . He assumed I would be against it and again seemed a little nervous . I said nothing . He only used a Sony portable CD and said it's battery PSU was in it's favour . Speakers Quad 63's . I think he used a Thorens turntable . The system was extremely good . The amps had his LM317 PSU upgrade .
A company I work with can now get things built cheaper in the UK ! We were paying £144 for some parts in 2004 . £22 in China about 2006 from an aerospace supplier . Now it's all changed . We never let them see the finished product and buy from many sources who have no idea who the others are .
On Sony ES the measurements were at - 120 db for PCB isolation effects . They reasoned it was electromagnetic induction ( that's them speaking not me ) . Philips also noticed strain gauge qualities in 16 bit crown chips ( last 2 bits if memory is correct , put blue-tak under chip , heat is OK , Naim Audio info from Robin in service dept if asking , sure no one at Naim would mind ) . Sony still went ahead with PCB isolation in ES range as they felt they could hear it . Ironically Linn LP 12 was how they thought of it as Linn were talking about all aspects of isolation . Sony bought a Linn Naim system which they investigated . That strangely became ES with Bio-tracer turntable . The speakers which had patented square drive units were inspired by the Isobariks KEF B139 . I only know this second hand although was involved in a bit of it . It all seems correct to me .
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Hang on people, we are talking two levels here.
One level is to isolate the entire device from vibration, a task I accomplish by using some (in my view) very good Norwegian made feet, which replace the standard fare on devices I have, except on the Karan, who uses them himself, and which are supplied as standard on all his products.
The other level is isolating printed circuit boards, over and above the feet. The first is not enough, and we should proceed on the second?
One level is to isolate the entire device from vibration, a task I accomplish by using some (in my view) very good Norwegian made feet, which replace the standard fare on devices I have, except on the Karan, who uses them himself, and which are supplied as standard on all his products.
The other level is isolating printed circuit boards, over and above the feet. The first is not enough, and we should proceed on the second?
The effect of vibration on components and circuitry itself can be measured. It is all part of the design process to make sure that all sources of distortion are addressed at the SAME level.
Gluing a capacitor to the circuit board will help some circuits. Gluing all capacitors to circuit boards just makes a mess of those that were designed to account for vibration issues.
The problem with "Magic" solutions is that there are some things that have a good reason for working under some conditions. When that is not understood then the process is a "Magical" improvement and is tried for all cases. When it does not work for most applications the "Magic" wears off and it is now audio nonsense. That is throwing out the baby with the bath water.
If you want to know which parts to use.., measure them! It isn't some secret or arcane technology. If you want to compare topologies, simulation will give you some insight, then you have to do actual tests!
The real issue is experience. I can find resistors that have less total distortion than many others but quite a bit of 9th harmonic. They would not be a good choice. I can measure my supply rails and regulate them so they match within .01% but again that may actually be a bad idea.
So there is a need for "Golden Ears" and real engineering. Neither is by itself fully capable of solving real world problems.
Gluing a capacitor to the circuit board will help some circuits. Gluing all capacitors to circuit boards just makes a mess of those that were designed to account for vibration issues.
The problem with "Magic" solutions is that there are some things that have a good reason for working under some conditions. When that is not understood then the process is a "Magical" improvement and is tried for all cases. When it does not work for most applications the "Magic" wears off and it is now audio nonsense. That is throwing out the baby with the bath water.
If you want to know which parts to use.., measure them! It isn't some secret or arcane technology. If you want to compare topologies, simulation will give you some insight, then you have to do actual tests!
The real issue is experience. I can find resistors that have less total distortion than many others but quite a bit of 9th harmonic. They would not be a good choice. I can measure my supply rails and regulate them so they match within .01% but again that may actually be a bad idea.
So there is a need for "Golden Ears" and real engineering. Neither is by itself fully capable of solving real world problems.
For vibration isolation, even that due to the components themselves (transformer magentostriction for example), I recommended only half-jokingly once that a product from Newport they called EVIS should be used. It was designed to create an inertial frame using accelerometers and transducers (EVIS = Electronic Vibration Isolation System).
I thought they must have lost their sense of humor, not naming it ELVIS... But Newport, it seemed to me, was in those days trying to be a bit snooty. They bragged about how many doctorates their staff had, for example.
I thought they must have lost their sense of humor, not naming it ELVIS... But Newport, it seemed to me, was in those days trying to be a bit snooty. They bragged about how many doctorates their staff had, for example.
One family I know has an average of 2! The Mother had 4 everyone else of course at least one. (Three kids, you can work out how many got 2!)
Reminds me of the Big Bang Theory episode where one of the characters, I think Sheldon's "girlfriend" Amy Farrah Fowler, talks about how, instead of exchanging presents at the winter holidays, they gave papers.
I will have to pick this up in the morning . Big Bang I didn't realize was a Joke made by Fred Hoyle . Then someone did a bit of maths and said it is correct . The truest words often spoken in jest . I think I believe big bang .
Good night .
I get peoples names wrong so correct any mistakes .
I believe in oscillation of Universe that consists of big bangs and big collapses.
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