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Old 13th January 2013, 09:33 PM   #61
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The missing ground should be at the C5, R35, R8 node just like the A40. Like Antoinel says, it's a bootstrap input to increase the input impedance.
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Old 29th January 2013, 10:14 PM   #62
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Nelson, any words of wisdom on how to bias this thing? Also, why the 22 ohm resisitors on the base of each output transistor? Current sharing, stability, artistic license?
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Old 30th January 2013, 03:14 AM   #63
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they're 220R resistors

you can call them artistic stability supporters

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Old 30th January 2013, 04:37 PM   #64
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Quote:
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Also note that resistors are XXX plus multiplier: 1001 is 1K.
I like to quote myself. I find it elevates the tone of my conversation.

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Old 30th January 2013, 05:16 PM   #65
Gyuri is offline Gyuri  Hungary
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Watch out Papa, this is already the first signs of a cult of personality.

Anyway, thanks for the clarification.

Gyuri
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Old 30th January 2013, 06:09 PM   #66
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Quote:
Originally Posted by Nelson Pass View Post
Also note that resistors are XXX plus multiplier: 1001 is 1K.
So a 221 ohm resistor should be 2210 like R10.

I'm finding that collector current needs to be about 50mA per transistor to smooth out the crossover region.
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Old 2nd February 2013, 10:10 PM   #67
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AB100 Amplifier - Micro Article by Nelson Pass
Since villagers armed with pitchforks and torches have begun camping out my front door demanding a Class AB power amplifier,
and Whereas, I am inclined to demonstrate my goodwill in this manner and do in fact have a 13 year old piece laying around unpublished
So it will be any article about AB100 published at "articles section" on FIRST WATT or Pass DIY?
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Old 2nd February 2013, 11:16 PM   #68
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Quote:
Originally Posted by Loudthud View Post
So a 221 ohm resistor should be 2210 like R10.
.......
221 = 22 x 10^1 = 22 x 10 = 220

or , just read them as 221R resistors
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Old 3rd February 2013, 12:06 AM   #69
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Originally Posted by georgescooo View Post
So it will be any article about AB100 published at "articles section" on FIRST WATT or Pass DIY?
You saw it already. It was a uArticle

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Old 6th February 2013, 03:23 PM   #70
Braun_ is offline Braun_  Brazil
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Basic question. The original design produces 100W@8Ohms with 4 output pairs. If I want less power, around 25 to 50W, Can I just reduce the numbers of output transistors?
Thanks
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