John Curl's Blowtorch preamplifier part II

[jacco vermeulen]

Looks

Why Sir, it even looks as good as a Magnet MA400 for 70k Thai Baht.

 

[jneutron]

Hey Inductive man, whats causing the rise, too much mass or too low a BL..

What is it a depiction of? It's too fuzzy to make out the axis and the top.

I've given up arguing that the diode equation is fundamental for bipolar design.

What's a diode?😉

jn

 

[auplater]

valves vs. sand

To be sure I also have enjoyed all valve systems very much.

Plus... the further north you live, the less your teeth chatter while listening to them...😉😉

 

[scott wurcer]

What's a diode?😉

jn

5U4?

Popped off a snail mail package Saturday, all datasheets should be on line but the AD815 big slug package might need a search (just in case you wanted to play with them).

 

[john curl]

Last night I got a call from the first PhD EE that I ever hired. We first met in 1972, and I had a problem in 1974 that was beyond my ability. We needed an anti-aliasing filter with relatively low phase shift, for a custom made (by me) bucket brigade delay line of the highest quality. He came up with a wonderful solution and we used it in a speaker design that John Meyer and I put together in Switzerland.
My colleague the EE went into electric car design about 30 years ahead of today, and he never made anything significant from the early efforts and patent(s) that he got then. It goes that way, sometimes.

 

[jneutron]

5U4?

Popped off a snail mail package Saturday, all datasheets should be on line but the AD815 big slug package might need a search (just in case you wanted to play with them).

5Y3GT??

Thanks, I'll look out for it.

jn

 

[a.wayne]

Last night I got a call from the first PhD EE that I ever hired. We first met in 1972, and I had a problem in 1974 that was beyond my ability. We needed an anti-aliasing filter with relatively low phase shift, for a custom made (by me) bucket brigade delay line of the highest quality. He came up with a wonderful solution and we used it in a speaker design that John Meyer and I put together in Switzerland.
My colleague the EE went into electric car design about 30 years ahead of today, and he never made anything significant from the early efforts and patent(s) that he got then. It goes that way, sometimes.

Yes , so it is, look at those who went into electric almost 100 yrs before he did..

 

[jneutron]

Just patenting any old thing doesn't mean there will be a benefit. There needs to be a market as well. If nobody wants it, the money was wasted.

jn

 

[elektroj]

Adventures in Patentland

Just patenting any old thing doesn't mean there will be a benefit. There needs to be a market as well. If nobody wants it, the money was wasted.

jn

Speaking of patents .. take a look at this gem that I've discovered a few days ago

 

[Triodethom]

5U4?

Popped off a snail mail package Saturday, all datasheets should be on line but the AD815 big slug package might need a search (just in case you wanted to play with them).

That's not a diode this is a diode

An externally hosted image should be here but it was not working when we last tested it.

this is a diode.http://vinylsavor.blogspot.com/2011/08/tube-of-month-866a.html

 

[31697B]

I just grabbed a couple of graphs for some Toshiba devices sold as complements of eachother. This result is typical of many if not most, Beta/Va quite different as well as saturation characteristics. Absolute Vbe's also all over the place. You can match beta's at one Vce that's about it.

I found via curve tracer that some of the best compliments were not from those listed as compl.

Thx-RNMarsh

 

[scott wurcer]

I found via curve tracer that some of the best compliments were not from those listed as compl.

Thx-RNMarsh

The complements listed are usually at the same breakdown voltage and ft. The mobility of holes vs. electrons will push some parameters out of complement, it's the users choice which. You can't measure storage times or ft on a curve tracer.

 

[Nelson Pass]

Speaking of patents .. take a look at this gem that I've discovered a few days ago

Can you spell Cascode?

😎

 

[scott wurcer]

Can you spell Cascode?

😎

1972 National or Siliconix app notes. 🙂

 

[gpapag]

but the AD815 big slug package might need a search (just in case you wanted to play with them).

What an IC! http://www.analog.com/static/imported-files/data_sheets/AD815.pdf

Will he play with an AD8421 too?

I've given up arguing that the diode equation is fundamental for bipolar design.

You mean the Shockley diode equation?

George

 

[john curl]

Yes George.

 

[scott wurcer]

What an IC! http://www.analog.com/static/imported-files/data_sheets/AD815.pdf

Will he play with an AD8421 too?



You mean the Shockley diode equation?

George

I see they have removed the "real" package from production. I have been handing out my last stash of the big copper SIP version that really does 5W. I stuck with 8-legs for ease of use, for audio frequencies there are choices to try first.

I just meant the Ic vs Vbe relationship.

 

[jneutron]

Jan,

Package received.

I am totally impressed. So much so, that I have no choice but to heavily re-write....sigh.

John

 

[marce]

HTTP 301 This page has been moved

🙂Ignore the text it links to the real package.

Was this the daddy of todays leadless SMD packages?

 

[gpapag]

the big copper SIP version that really does 5W. I stuck with 8-legs for ease of use, for audio frequencies there are choices to try first.

I just meant the Ic vs Vbe relationship.

I see
The 24 legged version has some guts too, 26dBm. That’s 0.5W into 50R
Looking at performance diagrams I understand your past words about “some ADSL drivers” that can easily compete with discrete audio line/headphone drivers

George