Please check this LM3886 layout for me

[CJ900RR]

So im trying to improw my LM3886 Gainclone and im just finished with this layout: http://www.leetmaa.se/diy/new.pdf

Can you please have a look and give me any comment's about my selected values and clear out some questions?

Partlist:

C1: 0,1 uF film-cap polypropylen
C2: 0,1 uF film-cap polypropylen
C3: 10 uF alm-cap elektrolyt
C4: 220 pF film-cap polypropylen
C5: 100 uF alm-cap elektrolyt
C6: 10000 uF alm-cap elektrolyt
C7: 10000 uF alm-cap elektrolyt
C8: 0,1 uF film-cap polypropylen
C9: 1,0 uF axiell-cap polypropylen

R1: 33 kOhm 1% 1/4W
R2: 1 kOhm 1% 1/4W
R3: 1 kOhm 1% 1/4W
R4: 39 kOhm 1% 1/4W
R5: 10 Ohm 2W
R6: 47 kOhm 1% 1/4W
R7: 2 Ohm 2W

J6 is a jumper if you dont want the mute-function.

Thank's in advance, best regards...

[Bazukaz]

Quite good layout.

[Bazukaz]

Just noticing what is the reason to put R5(10 Ohms) resistor between the output ? It will burn out quickly and degrade power by much.
Also, i would shorten input traces - on the board , low level signal is not shielded , so shorting the leads may decrease noise.

[CJ900RR]

Originally posted by Bazukaz
Just noticing what is the reason to put R5(10 Ohms) resistor between the output ? It will burn out quickly and degrade power by much.
Also, i would shorten input traces - on the board , low level signal is not shielded , so shorting the leads may decrease noise.

R5 is there in a design from national, but at the single-supply unit paralleld with an 0,7 uH inductor. Forgott to mention the inductor. But i can take it away and ad a jumber instead.

And i think i can shorten the input traces.

Thank you. How does the other values look?

[Bazukaz]

Inductor is a good idea , but if you don't plan to use really long speaker cables , this can be left out.Adding more components than necessary may induce some other problems.

[CJ900RR]

Originally posted by Bazukaz
Inductor is a good idea , but if you don't plan to use really long speaker cables , this can be left out.Adding more components than necessary may induce some other problems.

Well im just going to use "normally" speaker-cables so i can leave that one out.

I updated the pdf-file; http://www.leetmaa.se/diy/new.pdf

Please have another look and let me know. I also updated my first post; R5 is now a jumper.

Thank you again...

Edit: I was about to edit my first post but suddenly that button is missing.

Note: R5 is now a 0 ohm's jumper

[Bazukaz]

I can see no problems with your layout.However , the only way to test is to really build lt . good luck

[CJ900RR]

Originally posted by Bazukaz
I can see no problems with your layout.However , the only way to test is to really build lt . good luck

Sound good

I have allready built a simular version, but this one will be better i think. Again, thank you for your time!