No, as I said, the triode comment is valid in its own personal narrow context.
The less you drag a vc carrying hf current across a magnetic surface, the better, so there's certainly an advantage to splitting it up. I suspect the big time speaker guys here can give much more information, they do it for a living.
That's why I put the home use thingy at the tail end of the post.
I'm not sure if I've made it clear. If you make a pole center piece out of lots of thin discs of iron glued up, you have not removed the eddy currents but you have compromised the permeability of the material where the flux has to go to the back plate. By cutting it into wedges, you never have the flux trying to cross a cut.
The front plate same thing, you can't use a lot of thin disks 6 to 8 inches in diameter, as you still try to force the flux through glue layers and the coil field sees a washboard surface w/r to permeability.
The front piece should be cut radially from the gap out, so that the flux can go to the magnet unhindered by glue joints and yet eddies are reduced.
I assume the gaps do not need to reach the center of the pole piece, nor to the outer edges of the front plate or back plate. As you get farther from the coil, the vc induced time varying flux will reduce, so there's probably a reasonable best compromise distance.
I've no idea if the magnet has electrical conductivity for eddies, but I sure wouldn't try to edm a neo magnet that's magnetized, I don't think that can be done.
The magnetic designers here, both physicists and engineers, had to have the anisotropy of laminated irons pointed out to them, as they had designed a magnetic extension part that wasn't matching analysis..I pointed out that even with 4% thickness glue, the permeability was the series combination of 2 meters of iron with a mu of 3000 and 8 centimeters of air with a mu of 1.
yes, but they drew what appeared to be maybe 8 to 12 sections. If I were going to do it right, I'd keep the iron to .5mm give or take with .002 inch kerfs.
Don't recall what year the patent was.
jn
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Since ic are made up of many smaller parts. How many triodes can we use ? Say a cascoded 5670 driving 6080 cathode follower or 6336 or 6528 that can drive 600 ohms to say 35 volts or say 32 ohm headphones . All triode and good bandwidth ? Two big problems cost and size.
Why would that triode have to run hotter than normal ..?
Edit: saw triodethom answer ...
@jn,
If bandlimited , there should be no parasitic drag from hf, say 90hz/12db , if building a FR driver this would make sense ...
Totally agree about FR. But what about a woof that runs 20hz to 500 or 1k?
I suspect that even though my PA speakers, which run 40 to 3Khz on the 12 incher, have this effect, I don't know if I can hear anything.
I'd have to have eminence or somebody EDM some parts prior to assembly to compare two drivers. I was preparing to contact them for that, maybe even Tom Danley, but when I found the patent, I stopped.
jn
Yeah. Friend of mine wanted me to wire up an amp of his using some OCC wire that he would supply me. When I received it, I noticed it seemed a bit stiff given that it was fairly finely stranded. Then I stripped about half an inch of insulation off the end and went to twist it up good and tight before tinning it. But it wouldn't keep a twist. It just kept springing back.
And that's when I realized the the wire hadn't been annealed. Or if it was, it was only annealed to a hard temper. Bottom line, it was crap.
The big marketing gimmick of OCC is that it has fewer crystal boundaries, so your electrons flow oh so smoothly. But this crap would have had so many lattice dislocations in it that it's conductivity would have been a fraction of that of regular old ETP copper wire you can buy off the shelf at Home Depot.
se
What about this one JC ... 
Essence Jasper III mono block amplifiers
Best amps ever built.
10 Mhz bandwidth at full power. 2 Farads of capacitance per channel.
17 power supplies. Vibration coupled and mechanically isolated at all frequencies.
50% of the parts inside are military secrets. Parts are encapsulated in powdered quartz to sheild RF and make it impossible to steal technology.
Will make Krell and Mark Levinson sound like a broken Sony.
Edit: Nuff snake oil ..
Essence Jasper III mono block amplifiers
Best amps ever built.
10 Mhz bandwidth at full power. 2 Farads of capacitance per channel.
17 power supplies. Vibration coupled and mechanically isolated at all frequencies.
50% of the parts inside are military secrets. Parts are encapsulated in powdered quartz to sheild RF and make it impossible to steal technology.
Will make Krell and Mark Levinson sound like a broken Sony.
Edit: Nuff snake oil ..
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What about this one JC ...
Essence Jasper III mono block amplifiers
Best amps ever built.
10 Mhz bandwidth at full power. 2 Farads of capacitance per channel.
17 power supplies. Vibration coupled and mechanically isolated at all frequencies.
50% of the parts inside are military secrets. Parts are encapsulated in powdered quartz to sheild RF and make it impossible to steal technology.
Will make Krell and Mark Levinson sound like a broken Sony.
Edit: Nuff snake oil ..
I'll take 2. That case looks like recycled Corian shower surround.
John N,
I have been following the discussion on your interesting idea of a slit pole piece piecemeal, so it may have come up already, but here we go.
The slit pole piece concept minimizes eddy currents parallel to the pole piece. But these would already be dampened by using a shortening ring. This shortened secondary on the transformer with pole piece as core dissipates most flux modulation in the pole piece and with that eddy currents perpendicular to the pole piece. Hence no need for a slit pole piece as you propose, however thought provoking the idea.
The harder eddy currents to iron out would seem to be those caused by flux modulations across the magnetic gap. These cause eddy currents in the pole piece that are in the same direction of your proposed slices. Therefore, the gaps between them will not really hamper these currents.
Btw, it are also these vertical eddy currents which you have in aluminum VC-formers in spite of the typical single slit that prevents eddy currents in the horizontal plane. Kapton or other insulaters are therefore to be preferred as VC former, if it weren't for thermal issues.
I have been following the discussion on your interesting idea of a slit pole piece piecemeal, so it may have come up already, but here we go.
The slit pole piece concept minimizes eddy currents parallel to the pole piece. But these would already be dampened by using a shortening ring. This shortened secondary on the transformer with pole piece as core dissipates most flux modulation in the pole piece and with that eddy currents perpendicular to the pole piece. Hence no need for a slit pole piece as you propose, however thought provoking the idea.
The harder eddy currents to iron out would seem to be those caused by flux modulations across the magnetic gap. These cause eddy currents in the pole piece that are in the same direction of your proposed slices. Therefore, the gaps between them will not really hamper these currents.
Btw, it are also these vertical eddy currents which you have in aluminum VC-formers in spite of the typical single slit that prevents eddy currents in the horizontal plane. Kapton or other insulaters are therefore to be preferred as VC former, if it weren't for thermal issues.
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