LM3886 PCB request

[Aharon]

Probably has been asked before but I have searched and nothing came up.
Is there a PCB fro the LM3886(single sided,diy friendly,free) that you can point mre to.
Thanks
Aharon

[ingrast]

I developed a narrow strip PCB for 4 LM3886 you can mix and match for example for twin bridged 136W amps or biamp / triamp configurations etc.

The PCB has some jumpers because of required geometry and only includes basic support circuitry. I can also provide a matching preamp including required support.

Let me know if you are interested and I'll upload pdf's with schematics, component placing and artwork.

Rodolfo

[Ed LaFontaine]

Yes, I'd like to see your layout. A "balanced" bridge powered by +/-20V will provide about 70 watts from 2 chips. An Italian amp featured in Stereofool had that configuration and recieved good comments....what else!

[Aharon]

Hey,thanks Rodolfo.I am interested.I want to make a couple of powered monitors and this is really good help.
Thanks
Aharon

[ingrast]

Ed:

Will be back in a few hours with the uploads, I am not home right now.

The test amplifier I built is quiet and parsitics free. Even powered from a SMPS I designed.
It needs some heat management if driven hard.

Stay tuned.

Rodolfo

[Ed LaFontaine]

Thank You Rodolfo.

No need to hurry, I'll be doing this for the rest of my life

[bigparsnip]

Hi, if you start reading from this post there are quite a few designs for PCB's for LM3886 circuits (I think sound nerd built the one I finaly posted and it worked well, so that could be a starting point although I'm not sure about the others which could work too).

[ingrast]

Here are the files:

a3886s.pdf - Schematics

You may dispose of the preamp section if you don't need it or use and populate it as required. The configuration is for a dual bass / treble bridge.
I highly recommend TL072 and TL074 opamps here for they are specially selected for low noise and distortion.

Hope this helps, and please contact for any clarification you may require.

Rodolfo

NOTE: I had to resize drawings to fit 100K upload limit, resize again for printing, be carefull with scaling with the artwork file.

[ingrast]

a3886d.pdf - parts layout

I left out board traces to reduce file size

[ingrast]

a3886p.pdf - artwork

In fact there are 2 pcbs. The interconnects are shown in the previous file.

You can generate a 1:1 mask for photoprocessing with a good ink jet printer capable of 1440 dpi on ink jet transparency (not photocopy or laser!!!). Depending on processing method you may need to print positive or negative of this image.

Check carefully scaling !!!