John Curl's Blowtorch preamplifier part II

[gpapag]

Originally Posted by jcx

for sure it can be frustrating - but also an opportunity for all to improve their explanatory skills, even their understanding

so far this particular back and forth appears quite the model for what I would like to see here more often in technical discussions/disputes

much better than personal attacks, "black bag" rhetorical twisting of every word, appeal to inscrutable, conveniently unavailable "authorities"...

I hope that my “questioning” of jn distortion on the freq level falls under jxc umbrella.

It’s not that I have any real EM theory knowledge.
It’s not that I dispute jneutron knowledge on this and his capacity to dig on something others haven’t.

It is that there are at least two areas that this effect had a very high chance and good reason to be observed and studied by theoreticians and highly skilled engineers but it hasn’t.
The two areas are 1 coaxial cables, 2 Integrated circuits (ICs)
There are other areas as well (micro strip PCBs, miniaturized wave guides as used with slot phase array antennas and many other constructions in which AC voltages and minute conductor’s physical dimensions are met).

IMO, if there is one case which lends itself in precise theoretical modelling and controlled experimentation , this is the coaxial line.
Test of theory, test of material properties influence on the effects.

Can we start from there?

George

[Bonsai]

Originally Posted by RNMarsh

What's involved in annealing transistors (fets)? Could it be attempted outside a manufacturers lab?
-Thx RNMarsh

It's quite a normal semiconductor process. But the equipment is specialized and you need to do it at the right stage in the manufacturing process. I've never heard of annealing done in packaged devices.

Anneal temp will vary based on what you are trying to actually anneal.

[gpapag]

I found a link to one of the following at the hypex ncore thread.
This gentleman has at least an intriguing way of thinking (and doing)

http://www.steenduelund.dk/download/hoerelse.pdf
http://www.steenduelund.dk/download/duelund-filter.pdf
http://www.steenduelund.dk/download/HJEM3.WPS.pdf
http://www.steenduelund.dk/download/...correction.pdf
http://www.steenduelund.dk/download/...and%20room.pdf
http://www.steenduelund.dk/scanspeak8554.pdf
http://www.steenduelund.dk/download/dApolitto.doc
http://www.steenduelund.dk/download/kabler%20intro.pdf

George

[SY]

Originally Posted by RNMarsh

What's involved in annealing transistors (fets)? Could it be attempted outside a manufacturers lab?
-Thx RNMarsh

Unless you have the raw chips, you'll just cause a huge amount of contamination from degradation of the epoxy and siloxane adhesives.

[sofaspud]

Anneal temp will vary based on what you are trying to actually anneal.

I've spent a little time in a CVD (chemical vapor deposition) & annealing clean room. Wafers are placed on quartz carriers and sent into a tubular oven that's glows red hot inside. Most semiconductors are finished with a passivation layer (for protection) and pad mask etch (for external connections).

[Esperado]

Originally Posted by a.wayne

People with bad stereo , bad hearing or both , usually take to laughing at audiophiles and their choices ...

While Audiophiles have so good hearing that they are even able to listen to things that does not exists. On fantastic stereos made of two 13cm full range speakers on precious wood flat panels powered by a huge 3Watts Class A amplifier they can use to heat their home.

At least unwashed people have time to listen to music while his audiophile neighbor is listening endless the same 10 seconds samples of old worn vinyls, trying to figure out the changes brought by some new magic golden cone to the reproduction of the silence after Herbert von Karajan stopped to wave his arms.

The researchers tried to invent special drugs to treat them: "Blind tests". It was a failure, This disease is incurable. And expensive: with just the money they spend for their power cables, you can feed 10 African villages and their marabouts.

However, i can have good time, inviting two of them for a dinner and enjoy. or just, sometimes, reading your contributions to science and your appreciation of my stereo system (you've never heard) on DiyAudio.com.

[gootee]

<Grin!>

[marce]

Very funny but astute

[scott wurcer]

Originally Posted by RNMarsh

What's involved in annealing transistors (fets)? Could it be attempted outside a manufacturers lab?
-Thx RNMarsh

Basicly no the temperatures involved would destroy later processing and/or the package, we had a physics professor claim he could but when we talked he was claiming he could remove all noise. One rule NEVER ever sign an NDA with kooks.

EDIT - You also need something to getter what you want to remove, even scratching the backside worked somewhat then backside argon implant was better. With DI you might need topside gettering, all need to be part of the process.

[magnoman]

Originally Posted by gpapag

IMO, if there is one case which lends itself in precise theoretical modelling and controlled experimentation , this is the coaxial line.
Test of theory, test of material properties influence on the effects.

Can we start from there?

George

George
At least for the current crowding effect being discussed wouldnt the co-ax symmetry prevent it all together?

Thanks
-Antonio