300W 'modulated bias' cascode Killer Amp - diyAudio
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Old 10th November 2005, 11:27 PM   #1
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Default 300W 'modulated bias' cascode Killer Amp

Here is the first pic of the 300W version of the simple Killer Amp.

The complementary differentials are cascoded allowing the same Ft > 200MHz, Hfe > 450, 65V transistors to be used for inputs diffl's and driver/buffer with 4 pair of matched IRF complementary MOSFETs.

The cascode BJTs are biassed from a divider in the following driver which is modulated with the driver signal out of phase with the input/feedback signal to the differentials. This reduces THD by 2 to 3 times over a standard biassing arrangement.


I stll haven't bought that better camera.

Cheers,
Greg
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Old 11th November 2005, 03:37 AM   #2
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Guru , I think a schematic would be a better option than this photograph

Cheers
K a n w a r
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Old 11th November 2005, 04:31 AM   #3
sam9 is offline sam9  United States
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Ditto. Your digital camera has even crappier resolution my mine.
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Old 11th November 2005, 05:04 AM   #4
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Hi Kanwar, Sam 9.

OK,OK I'm shopping for a camera tomorrow! They let me out on day release Saturdays.

Here's the topology.

http://members.dodo.com.au/~gregball/guru_007.htm

Full schematics come with the kit.

Cheers,
Greg
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Old 11th November 2005, 05:15 AM   #5
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Ok Greg,

Purchase a digital Camera with "OPTICAL ZOOM" only , donot take digital zoom instead of it, because optical zoom is much clearer than digital zoom, after all optical zoom is another form of image amplification....

regards,
K a n w a r
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Old 11th November 2005, 05:52 AM   #6
Electrons are yellow and more is better!
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Just wondering, but don't you get a rather high output impedenace when you have drain out?

The distortion is reduced you say by 2-3 times, from what?
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Old 11th November 2005, 06:04 AM   #7
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This line made me laugh out of Hell......



"You work for small outfits, and can do weird stuff because there is no one there to keep you under control"


Peranders, Is this really from one of the 29 commandents of Jocko Homo......HAHAHAHAHAAAA

What:?

Lots of Signatures PA
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Old 11th November 2005, 06:16 AM   #8
Electrons are yellow and more is better!
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Quote:
Originally posted by Workhorse
Peranders, Is this really from one of the 29 commandents of Jocko Homo......HAHAHAHAHAAAA
Word by word by the Great One from Texas. Nothing added or removed.
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Old 11th November 2005, 06:37 AM   #9
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HaHaHa

"You work for small outfits, and can do weird stuff because there is no one there to keep you under control"

I resemble that remark.

Peranders,

THD is 2 to 3 times lower than with a conventional fixed bias cascode. More to come.

The Zout should prove even lower than the smaller 2 o utput pair Killer Amp as the doubled output stage will have 2 x transconductance so 2 x voltage gain, so 2 x NFB, so 2 x lower Zout !

Cheers,
Greg
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Old 11th November 2005, 06:45 AM   #10
Electrons are yellow and more is better!
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Have you verified your claims about the dist? From what to what? 0.0046 to 0.0023% or 0.3 to 0.1%?
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