John Curl's Blowtorch preamplifier part II

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Pavel, and others:

I'm finally measuring and matching Transistors.
Currently I'm Matching pairs of NpN and PnPs,
using 12V + and -. Measuring emitters in
tightly matched pairs of 100k ohms and
10k ohms.

Vbe--I've got plenty matched 1/10 of a milivolt for the pre-amps' and the input
to power amp's differential pairs. .0000x

Then, I guess now I send a signal through and at what level?

Now I'm trying to figure out how to Match the driver transistors
TO-66 or TO220
and
then want to match the output transistors. I'm guessing I
use a separate JIG for testing the output transistors.

These are going to be tricky tricky because they are the older TO3 devices.

Appreciated comments regarding best methods.
 
Thought I was going mad for a bit then - the kick drum sounded so bad...
Interesting.

A buddy of mine designed and built a Drum mic.
He had sessions scheduled for two weeks in LA,
and when he went through security, they didn't
believe him.

The fun started when the FBI showed up,
then with everyone he knew, neighbors in
a multi-block area.

I think the mic was pretty good.

Cheers
 
Would you mind sharing test circuit schematics? Regarding power devices, you might like to use heatsinks to reduce hFE and Vbe temperature effect, in case you would like to test at operating currents.

I guess that would help.

Here is the link from Ian Fritz - LINK.

Now that I think about it, I forgot to subtract the other
side. Those are just raw readings.

I haven't thought about at operating current...but then
I do need heat sink and a couple of sockets for the
drivers and TO3s.
 
Kind of gives new meaning to the words...

"Tiny kangaroo down sport,
tiny kangaroo down."

"And now for the rest of the story"

VO: At the Australian National Stew Cookoff, an observer watched as
last years champion left his booth to, well, use the little boys room (if I can say that here)
and didn't leave anyone to watch his prize winning stew. It was observed that
an unwieldy competitor (we presume) walked over and placed the contents of
a plastic bag into that prize winning stew...

...all the while singing quietly,
Tiny kangaroo DOWN sport,
tiny kangaroo DOWN,
while hurriedly stirring in
the new contents to the kettle.

editors note: Keep the song under 30 seconds to avoid royalty payments.
 
AX tech editor
Joined 2002
Paid Member
That's why I have grown hares on my chest.

Haha!

quote:

'Hares and jackrabbits are leporids belonging to the genus Lepus. Hares are classified into the same family as rabbits and are of similar size, form, and diet as rabbits. They are generally herbivorous, long-eared, and fast runners, and typically live solitarily or in pairs. Hare species are native to Africa, Eurasia, North America, and the Japanese archipelago.'

Sorry couldn't resist,

Jan
 
Hard to figure-out with a demo done with so calling "drums sounds" coming from a Rythm box. ;-)

Anyway, we used to equalize all instruments in studio, during decades, with analog mixing desks. They introduce a lot of phase/GD shifts. Usually, each instrument were supposed to sound better *after* equalization ;-)
 
I'm shamefully sorry my poor quality speakers don't meet your approval.
Oh, man, I don't understand your reaction, it was just a Joke about "acceleration captors". I have no idea what your speakers are.
My friends always joked at me because i used to hit enclosures walls with my fingers, even before to begin to listen to any speakers, to figure-out how well they are damped, and found this simple method as revealing than any 'more technical' way, like acceleration captors.
I used sand too, in order to find the best places to add damping reinforcements...
During decades, i found quarter waves transmission lines enclosures better than others in bass reproduction. Until i realized that the added damping provided by the inner walls of the transmission line was the main reason of its quality difference.
 
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