MOSFET/MOSFET amplifier - Page 2

jarek · 20th June 2004, 01:21 PM

And the second I like much better.
Yes Jam, now here I can try current sources...
Upupa, I am afraid of thermal stability too, but this will be next step to consider.

I will be happy if all of you would continue your help.

Clarkcr · 20th June 2004, 03:23 PM

HEllo,

How or why did you come up with 100u for your caps? Why not 80u or why not 400u?

I noticed your MOSFETs are different numbers, for expample, one is 9640 the other is 640....is one an N-type and the other P-type...I'm being a little redundant here from my other thread on the X1000...forgive me.

jarek · 20th June 2004, 06:43 PM

Quote:

I is kind of similar to the ' Simple MJ amplifier' you can find on the net and on this forum.

Couldn't find.

Any directions, please..

tschrama · 21st June 2004, 03:26 AM

Will do ... no problem... but I find your last two versions not an improvements. Your first circuit look OK to me, but haven't you made a error with the feedback arangement of the last two versions..

tschrama · 21st June 2004, 03:33 AM

http://www.homestead.com/whaan/files/page5.html

tschrama · 21st June 2004, 03:40 AM

http://perso.wanadoo.fr/jm.plantefeve/sche.html

this page should be of interest too, especially the botttum circuit...

cu,
Thijs

jarek · 22nd June 2004, 03:12 PM

Thanks, tschrama.

Jam, did you mean something like that regarding current sources?
I would like to improve a performace for 4 ohm speaker but how it get?

jam · 22nd June 2004, 04:05 PM

That is what I ment, don't forget the gate resistors for the current sources. For use with 4 ohm loads use two pairs of output.

Regards,

Jam

jarek · 22nd June 2004, 04:14 PM

Thanks Jam,
I am afraid, that two pairs of output pairs do not improve this. It depends mostly on bias current (total amount). If the sum of bias is the same there wil not be an efect. Or maybe I am wrong?
Regards

jam · 22nd June 2004, 04:47 PM

Jarek,

Two pairs will help and more bias is always a good thing (as long as you have the heatsinking and exceed the safe operating conditions of the mosfets.

Regards,
Jam

22nd June 2004, 04:14 PM	#19
jarek diyAudio Member Join Date: Dec 2002 Location: Poland	Thanks Jam, I am afraid, that two pairs of output pairs do not improve this. It depends mostly on bias current (total amount). If the sum of bias is the same there wil not be an efect. Or maybe I am wrong? Regards __________________ Jarek

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20th June 2004, 03:23 PM	#12
Clarkcr diyAudio Member Join Date: Jun 2004 Location: Houston, TX	HEllo, How or why did you come up with 100u for your caps? Why not 80u or why not 400u? I noticed your MOSFETs are different numbers, for expample, one is 9640 the other is 640....is one an N-type and the other P-type...I'm being a little redundant here from my other thread on the X1000...forgive me.

21st June 2004, 03:26 AM	#14
tschrama diyAudio Member Join Date: Jul 2001 Location: The Netherlands	Will do ... no problem... but I find your last two versions not an improvements. Your first circuit look OK to me, but haven't you made a error with the feedback arangement of the last two versions..

21st June 2004, 03:33 AM	#15
tschrama diyAudio Member Join Date: Jul 2001 Location: The Netherlands	http://www.homestead.com/whaan/files/page5.html

21st June 2004, 03:40 AM	#16
tschrama diyAudio Member Join Date: Jul 2001 Location: The Netherlands	http://perso.wanadoo.fr/jm.plantefeve/sche.html this page should be of interest too, especially the botttum circuit... cu, Thijs

22nd June 2004, 04:05 PM	#18
jam diyAudio Member Join Date: May 2001 Location: Charlotte,NC,USA	That is what I ment, don't forget the gate resistors for the current sources. For use with 4 ohm loads use two pairs of output. Regards, Jam

22nd June 2004, 04:47 PM	#20
jam diyAudio Member Join Date: May 2001 Location: Charlotte,NC,USA	Jarek, Two pairs will help and more bias is always a good thing (as long as you have the heatsinking and exceed the safe operating conditions of the mosfets. Regards, Jam

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