DIY progress report

One of these days I'm just going to put it on a DVD and toss it out, probably after I lose my mind.

Another language barrier for me. Is this mean you will do it or you will not do it?

If it is positive answer (will do it), please include me in the list, Mr. Pass :D. I will pay for the DVD and shipment.

Hi, Jacco,

Yes, bunch of Nelson Pass articles which can be downloaded from internet has already forming a book
But I'm expecting to see cct's/articles that NP has never made public yet. I'm sure there are alot of it

I see those cct's/articles quite different than handbooks like DougSelf or RandySlone. Books like Dougself is a guidance for making audio amplifier. Mr. Pass' schematics is a guidance for making "good sounding" audio amplifier. Even it is in a form of a schematic without any word at all. :D
What can you say. A picture (cct) equals thousands of words.
 
Currently, I am still exploring minimalism

Once I read that some of people sending NP better caps or accesories, and he wrote that he would appreciate more if someone is sending more linear device.
At the time I read that post, I dont take it seriously, at that time I take a transistor as it is, a perfect device.

Now somehow my search for ideal amp is stuck with transistor nonlinearities.
I read about the background of F series amp. Why make 300W power amp if 299W is not good?
So, why make 10 or 20 transistor power amp if each is producing more nonlinearities/IM?

But for now, I haven't reach the Zen era. I'm still enjoying the Threshold/Smartbias/Efficient classA era. Still a lot more interesting stuff this era.
 
Ipanema said
I'm confuse. Pls enlighten me on this.


Here is a Thevenin version.
The Norton version with current source and shunt resistor
gives the same answer.


I think I got the equations and numbers correct.

Tom
 

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dqswim said:
The dog days of summer are nearly over.B]


"Today, dog days occur during the period between July 3 and August 11."

"In the summer, however, Sirius, the “dog star,” rises and sets with the sun. During late July Sirius is in conjunction with the sun, and the ancients believed that its heat added to the heat of the sun, creating a stretch of hot and sultry weather. They named this period of time, from 20 days before the conjunction to 20 days after, “dog days” after the dog star."


Silly me, I thought it meant the hot, humid, windless days near the end of summer.

Cal
 
Originally posted by Variac some time ago

I told Kent of a story I heard, that during lunch some grad students hung a piece of aluminum foil in the gap of the magnet and sent a signal through it. Of COURSE the sound was to die for.. I don't know if the actual layout of a cyclotron would allow this...

This is the traditional origin anecdote for [true] ribbon speakers. It's been so many decades that I can't remember which Chicago-area lab it was supposed to have happened at when I first heard it, or just which piece of HE physics gear was reputed to have provided the physically large gap with intense, linear magnetic field. I imagine those details change from telling to telling.

Ten to one it's apocryphal...but I do know some HE physics sorts who are pretty deeply into good sound reproduction, so I won't say it's impossible. Hmmm. I wonder if Dan is still working at Fermi...
 
The one and only
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When I was at ESS I experimented with an actual tweeter
which operated on a similar principle. A circular lightweight
foil diaphragm is placed between two coils, one front and one
back, all aligned to the same plane. When you run current
through the coils and modulate it, the eddy currents in the
diaphragm cause it to push air. The concept came from an
old acoustics journal, and I simply implemented the original
drawings. I also tried iron oxide coated mylar sheet as a
diaphragm.

As a loudspeaker, it was not a practical item.

:cool:
 
The eddy current driver sounds as though it would be inefficient. On the other hand, it might be just the ticket for a CCS amp.
Assuming that iron oxide coated mylar means magnetic recording tape, I have experimented with this with fair results. It's inefficient. Conceptually, I think it's likely that the iron oxide will experience a hysteresis effect, which would surely lead to distortion, but I don't remember it being audible.

Grey