A Faraday cage is an electrostatic shield. It's the conductivity of the material that matters much more than thickness.
Thickness counts more for magnetic shielding, along with the permeability of the material.
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Eddy currents, Steve, you should have known them. And penetration depth.
Thickness counts for Al and Cu very, very much, when we speak about lower frequencies.
Thickness counts for Al and Cu very, very much, when we speak about lower frequencies.
That's same or similar. 1st stage is linear 20dB, followed by Tau3 (i.e. 75us).
On my MPP thread i have posted a lot of circuits that did just that. Linear amplification
( i prefer 30dB out of some reason ), 75usec pole passive ( actually i do prefer the transimpedance version ) and then active equalisation of the deeper frequencies. I think it is a very good recipe for success.
Buffering Opamps well does work fine too, so Pavel, i like your block diagram.
( i prefer 30dB out of some reason ), 75usec pole passive ( actually i do prefer the transimpedance version ) and then active equalisation of the deeper frequencies. I think it is a very good recipe for success.
Buffering Opamps well does work fine too, so Pavel, i like your block diagram.
My normal is 30db input open loop transimpedance. Second stage, in this case, feedback all balanced adjustable EQ from off board.
snake oil is wonderful stuff
there's been more people cured by snake oil
than all other medicines combined.
It is well known that a THICK aluminum case will also shield the magnetic component of the audio spectrum, as well as RF. Tin foil will not.
Yes, aluminum shields RF better then copper. Copper is great for heat sinks though.
See the new D`Agostino amp.
See the new D`Agostino amp.
Does anyone know what words often go before one of the stupidest statements you will hear that day?
"I am an engineer and I know that...."
Looks to me like the Audio Note preamp is using a lead free solder. They do not flow the same as leaded solders. Folks who try to make lead free solder connections look the same as lead based solder ones end up with poor joints. I am an engineer and I know that because I set up test boards with different solder types and techniques and measured the results.
Military specifications work for the military needs, doesn't mean they are correct for other applications.
As to a 94 pound case, it probably started as a solid chunk of plate and was milled out. So the 94 pounds started as at least 400 pounds at $3 or more a pound just for the metal! The machining cost would depend on how well equipped the shop is. I have seen some truly impressive shop work out of California shops making audio cases. Much better than I know how to do. Never seen anything close in terms of quality even from Europe. A significant advancement over the Westinghouse guides.
BTY Boeing now uses the same technique to make parts as big as wings! Really Really big milling machines. Of course they remelt the scrap! End cost is supposed to be the same as the older welded or riveted versions.
"I am an engineer and I know that...."
Looks to me like the Audio Note preamp is using a lead free solder. They do not flow the same as leaded solders. Folks who try to make lead free solder connections look the same as lead based solder ones end up with poor joints. I am an engineer and I know that because I set up test boards with different solder types and techniques and measured the results.
Military specifications work for the military needs, doesn't mean they are correct for other applications.
As to a 94 pound case, it probably started as a solid chunk of plate and was milled out. So the 94 pounds started as at least 400 pounds at $3 or more a pound just for the metal! The machining cost would depend on how well equipped the shop is. I have seen some truly impressive shop work out of California shops making audio cases. Much better than I know how to do. Never seen anything close in terms of quality even from Europe. A significant advancement over the Westinghouse guides.
BTY Boeing now uses the same technique to make parts as big as wings! Really Really big milling machines. Of course they remelt the scrap! End cost is supposed to be the same as the older welded or riveted versions.
Please reconsider this, Joachim.
It is al matter of conductivity and permeability.
For some who have already contributed, please study the basics at
Eddy current - Wikipedia, the free encyclopedia
http://en.wikipedia.org/wiki/Skin_effect
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Dennis Morecroft in England ( DNM ) uses as little metal as posible so there is a skool of thought that any conductive and permeable material should be avoided near the circuit.
I have a DNM pre that sounds great but i find it hard to minimise hum from the phono input.
I have a DNM pre that sounds great but i find it hard to minimise hum from the phono input.
This sounds a bit like snake-oil, Joachim, especially if the material is not heavily non-linear. Copper surely does not "worsen" sound. Probably he might like EMI induced into the circuits - some really do prefer less defined sound resulting from more interference.
He makes a major efford with star earting and bandwidth limmiting but anyway, this is not how i whould build. Still PMA, look at what he does. It looks pretty and i was able to learn from his work.
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