Lm3886 pcb

livenicely · 15th November 2009, 06:47 PM

Here is LM3886 PCB Plz Check that all the components are ok and it is ready or not? If not make it final for all.

AndrewT · 15th November 2009, 07:39 PM

C3 is too low in value. Try >=72uF
R6 &C6 are specified on the National datasheet.
Separate the signal ground from the power/decoupling/zobel/mute/speaker ground.
C3 and R2 must go direct to the signal input return/ground pad. Nothing else may be on this dedicated ground reference.

rajudp · 16th November 2009, 03:17 PM

it is a working circuit from elektor electronics

peranders · 16th November 2009, 03:20 PM

22 uF => 7 Hz, not particularly small.....

AndrewT · 16th November 2009, 04:08 PM

then the 2u2F at the input is wrong. F-3dB~3Hz
I'd prefer to keep the input cap and change the NFB cap to suit. My real preference would be 4u7F for the input and 150uF or 220uF for the NFB.

Otherwise the amp will develop some AC voltage across the NFB cap and thus increase avoidable distortion.

C3 >= sqrt(2) * C1 * [R2+R1] / R3
The ratio of R3 to R2 determines the ratio of C3 to C1.

Bone · 16th November 2009, 05:08 PM

According to the original article, with a regulated supply (+/- 35v) they got 100 watts rms from this circuit!!!

Juergen Knoop · 16th November 2009, 05:21 PM

Quote:

Originally Posted by rajudp

it is a working circuit from elektor electronics

yes, it's small and has place for all the 'unnecessary' components, whether you fit them or not.
I have used it myself once in a multichannel project.
Small, cheap, fast to build and reliable operating...no complaints from me so far.
Regards

livenicely · 16th November 2009, 05:39 PM

Oh noooooo! Its always confuse me. its y i hav written make it complete. Now can u all guys decided which component should i use and their values as capacitors.

AndrewT · 16th November 2009, 05:42 PM

Quote:

Originally Posted by Bone

According to the original article, with a regulated supply (+/- 35v) they got 100 watts rms from this circuit!!!

you'll believe everything you read on the net!

100W into 8r0 requires an output of 40Vpk and 5Apk.
How does one get this from +-35Vdc whether regulated or not?

peranders · 16th November 2009, 06:02 PM

Quote:

Originally Posted by livenicely

... its y i hav written make it complete....

... please, could write in proper english? I'm not familiar with this chat english.

15th November 2009, 06:47 PM	#1
livenicely diyAudio Member Join Date: Nov 2009	Lm3886 pcb Here is LM3886 PCB Plz Check that all the components are ok and it is ready or not? If not make it final for all.

15th November 2009, 07:39 PM	#2
AndrewT diyAudio Member Join Date: Jul 2004 Location: Scottish Borders	C3 is too low in value. Try >=72uF R6 &C6 are specified on the National datasheet. Separate the signal ground from the power/decoupling/zobel/mute/speaker ground. C3 and R2 must go direct to the signal input return/ground pad. Nothing else may be on this dedicated ground reference. __________________ regards Andrew T.

16th November 2009, 03:17 PM	#3
rajudp diyAudio Member Join Date: Mar 2005 Location: Kerala	lm3886 it is a working circuit from elektor electronics

16th November 2009, 03:20 PM	#4
peranders Electrons are yellow and more is better! diyAudio Member Join Date: Apr 2002 Location: Göteborg, Sweden Blog Entries: 4	22 uF => 7 Hz, not particularly small..... __________________ /Per-Anders (my first name) or P-A as my friends call me

16th November 2009, 04:08 PM	#5
AndrewT diyAudio Member Join Date: Jul 2004 Location: Scottish Borders	then the 2u2F at the input is wrong. F-3dB~3Hz I'd prefer to keep the input cap and change the NFB cap to suit. My real preference would be 4u7F for the input and 150uF or 220uF for the NFB. Otherwise the amp will develop some AC voltage across the NFB cap and thus increase avoidable distortion. C3 >= sqrt(2) * C1 * [R2+R1] / R3 The ratio of R3 to R2 determines the ratio of C3 to C1. __________________ regards Andrew T.


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16th November 2009, 05:08 PM	#6
Bone diyAudio Member Join Date: Jun 2004 Location: Dorset, UK	According to the original article, with a regulated supply (+/- 35v) they got 100 watts rms from this circuit!!!

16th November 2009, 05:39 PM	#8
livenicely diyAudio Member Join Date: Nov 2009	Oh noooooo! Its always confuse me. its y i hav written make it complete. Now can u all guys decided which component should i use and their values as capacitors.

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