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Old 3rd June 2005, 09:35 AM   #11
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Better sound than Zen ? Your references are too low .
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Old 3rd June 2005, 10:31 AM   #12
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Default Re: Re: Re: 4w All Fet Class-a Amp

Quote:
Originally posted by DarkHorse


I don't know where this diagram from!but it's topology so simply that make me so surprise...
this is original schematic which I referenced:




you are right
my look was too quick
I have mismatched it with mentioned TCJ
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regards, Pawel
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Old 4th June 2005, 06:49 AM   #13
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I will build a sample to examine the sound class of this circuit,wait for my report please!about the day after tomorrow...I show you.
enjoy!

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Old 4th June 2005, 07:31 PM   #14
tlf9999 is offline tlf9999  United States
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There are substantial differences between yours and the original design but I like yours better.

Yours has the gain in the first and 2nd stages: both are drain-loaded-with-CCS and with global feedback. The original is a source-follower, followed by a drain-loaded with CCS for gain, without any feedback.

It is my experience that it is easier to have gain with small signal. So I was wondering if you can improve upon your design by using a source-follower in the 2nd stage (source follower + CCS).

You can then limit the feedback to the first stage as well (you can look into the Zen to see how to implement feedback in the first stage).

Let me know what you think.
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Old 4th June 2005, 08:40 PM   #15
JZatopa is offline JZatopa  United States
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I bet this would sound great with some high effeciency speakers. There is a lot you can do with 4 wrms a chan.
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Old 5th June 2005, 08:35 PM   #16
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http://www.selectronic.fr/upload/pro...que/7480SM.pdf

schematic like this :

Click the image to open in full size.

but with gain and current feedback

a Zenquito without driver ...

Click the image to open in full size.
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Old 6th June 2005, 01:46 AM   #17
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Quote:
Originally posted by tlf9999
There are substantial differences between yours and the original design but I like yours better.

Yours has the gain in the first and 2nd stages: both are drain-loaded-with-CCS and with global feedback. The original is a source-follower, followed by a drain-loaded with CCS for gain, without any feedback.

It is my experience that it is easier to have gain with small signal. So I was wondering if you can improve upon your design by using a source-follower in the 2nd stage (source follower + CCS).

You can then limit the feedback to the first stage as well (you can look into the Zen to see how to implement feedback in the first stage).

Let me know what you think.
hi,tlf9999:

At first I really don't know would it sounds better than the original version, because global feesback can cause other unexpectable problem...maybe it just decrease distortion in parameter..low distortion not mean it can sounds well..and I am so afraid the speaker's reverse voltage loop back and effect the first gain stage..
I don't want to use source-follower,I think IRF510's C-input is 180pF,driver current in 10mA is suitable.too strong driver stage perhaps let sound comes too "hard"(not sweet),I think..
but if you want use IRF530 or IRF540..this source-follower is needed to high frequency(10KHz or more)..


Quote:
Originally posted by DJNUBZ
I bet this would sound great with some high effeciency speakers. There is a lot you can do with 4 wrms a chan.
hi,DJNUBZ:
in fact,this circuit can output 4.5W(RMS) with 1.1A bias current.


have fun!
WINCO



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Old 6th June 2005, 03:36 AM   #18
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Hello,UltimateX86:

thanks your schematics,the topology is OK:
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Old 6th June 2005, 03:46 AM   #19
Ipanema is offline Ipanema  Malaysia
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Hi Ultimate86,

Your circuit looks like a Le' Monstre variation. Have you build those?

Regards,
Ipanema
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Old 6th June 2005, 04:02 AM   #20
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look my works,I soldering this last night...but too late,didn't finish yet!
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