My LM3875 and LM3886 gainclone PCB’s

[veteran]

After few tests of the gainclone amplifier I decided to make my own PCB’s for it. On the pictures below you can see the results of my work.

PCB for LM3875 has its own double bridge, place for 2 x 1800uF/50V Panasonic FC, input and NFB capacitors. LM3886 PCB is a typical application circuit from the National Semiconductor note.

The LM3875 topic was discuss so many times on this forum so I will just say: GC sounds GREAT! It was worth building a PCB for it

 

[veteran]

picture 2

 

[veteran]

picture 3

LM3886 board.

 

[peranders]

Nice work, indeed. I see also that you have use the same parts placement as I have done, power to the left. I think this is a good idea to keep power gathered at the left and signals at the right.

 

[veteran]

And one more...

 

[veteran]

Thank you Peranders It’s easy when using a double layer PCB – top is for power and the bottom for signal tracks (excluding speaker output).

 

[wigginjs]

Who did you have make your PCB? Mind if I inquire as to expense?

 

[veteran]

Of course One board for LM3875 costs 5$. The LM3886 pcb is cheaper – 2.5$ because it’s one layer, 70um cupper. All made by Hatron

 

[rs1026]

Can you post the PCB

Is it possible for you to post the PCB's on the forum?

 

[veteran]

Sorry – for now it’s impossible, maybe some day (now I’m a student) it will be a commercial project But I can send you a bottom side of the lm3886 board in pdf format if you want?

 

[steenoe]

Hi Damian
A pdf of the 3886 pcb would be nice.
Could you post the excact measures of the pcb too?

Steen.

 

[veteran]

This is a photo with dimensions of LM3875 GC board. Later I will make some PDFs with more information about LM3886 PCB.

 

[wigginjs]

What program did you use to design your board?

 

[veteran]

I’m useing Protel (99/DXP) for most of my pcb projects – I like this software

 

[veteran]

Documentation of LM3886 gainclone in PDF format (zip compressed):
lm3886gc_doc

 

[carlmart]

Of course One board for LM3875 costs 5$. The LM3886 pcb is cheaper – 2.5$ because it’s one layer, 70um cupper. All made by Hatron

Those prices are for how many boards?


Carlos

 

[veteran]

Price of one board for LM3875 (single channel) was 5$ (in PCB Factory), and 2.5$ for LM3886. There was about 100 of them only for people in AudioStereo forum.