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Old 26th August 2012, 10:12 PM   #1
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Default Current feedback class A monoblocks

Based on a design by Knut Harald Nygaard. Frequency range from dc to above 1 Mhz, 40W output, slewrate 200 V/uS. Been on my system for the past three or so years, having replaced a Plinius integrated. They sound exceptionally good to me, hope you like the pics.
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Old 26th August 2012, 11:56 PM   #2
DUG is offline DUG  Canada
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Nice and clean...in and out
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Old 27th August 2012, 04:14 AM   #3
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Sweet .....
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Old 27th August 2012, 01:59 PM   #4
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Which of Knut s designs is used, the no feedback one ?? Most of his designs look very good indeed.
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Old 27th August 2012, 03:52 PM   #5
Bigun is offline Bigun  Canada
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Judging only by the thread title, I'd hazard a guess the design is fig. 4.4. of this article:

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Old 27th August 2012, 05:28 PM   #6
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no, this one:

Voltage Amplifier & Current Buffer DIY

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Old 27th August 2012, 06:26 PM   #7
AndrewT is offline AndrewT  Scotland
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The voltage amp (post6) stage looks like it shows the out>> must be connected to the in<< This is global feedback. Or have I read the schematic wrongly?
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Old 27th August 2012, 06:38 PM   #8
knutn is offline knutn  Norway
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Since its my current feedback design, I think it must be this one(?): Power Amplifier
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Old 27th August 2012, 07:11 PM   #9
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Well, if anyone would know, it would be you!

So, have you done a FFT of the harmonics?

And, what is ur position on the relatively high THD figure of 0.02%?
How does that look at a higher freq, btw?

Asking a few other things too...

why not an F5 (similar power level, lower parts count, and same input pretty much)

and also... aw crud, lost the thought...

interesting design idea...

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Old 27th August 2012, 10:16 PM   #10
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Quote:
Originally Posted by knutn View Post
Since its my current feedback design, I think it must be this one(?): Power Amplifier
Lol, yes, that's the one. Only difference is that I doubled the output transistors and added some bells and whistles to it.

I didn't know you posted here, so I'll take the chance to congratulate you on a wonderful design. This was my third attempt at trying to build something that would replace the Plinius. I built the Hiraga 20W which sounded very sweet, but didn't have enough power, then the KSA50 which I hated, and then yours, which I fell in love right from the first moment I heard it.

At first I didn't want to waste money on the front pannels because I wasn't sure if it would be just a fad, but three years latter I think they deserved a nice face plate. So I ordered some and took some pics while I was at it, hence this thread now. (btw, where are all my posts from back then???).

The monoblocks are being driven by a preamp based on Walt's composite with the AD811 and are driving a couple of ATC SCM12 monitors.
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