PCBs for stereo bridged 3886

[soundNERD]

I was wondering if somebody has designed a stereo 220W amplifier using 4 lm3886s and made pcbs for it. If so, could somebody please post the pcb layout.

Thank you for your help, Mike

 

[cm961]

I designed a PCB for a bridged/paraelle amp but its mono. However, I only have one set of bypassing capacitors. They're located in the middle between the 4 chips. Does anyone know if this is good enough, or should each lm3886 have its own bypassing caps, and if so how big?

Pete

 

[soundNERD]

Would you mind posting it if you have it Peter?

 

[cm961]

Sure no problem.

Included in the zip file are four files. One shows the entire board, all components and tracks. One shows the top layer tracks. One shows the bottom layer tracks. And then I've included the schematic as well.

Cautions.... This is untested. I do plan on building it, but not during exams! Ok, now it only has one set of bypassing capacitors for the four op amps. I have no idea whether this is a bad thing or not. Perhaps with a regulated supply it would be ok, or maybe it's fine anyway. I've tested the circuit in circuitmaker and it seems to work fine there. It's pretty well straight from the application note. If you build it please let me know how it goes so I can make any changes before I build it! hehe.

Ok the file is too big to attach, so I'll go image by image.

Enjoy.

Pete

 

[cm961]

And here's the bottom layer...

Pete

 

[cm961]

The top layer....

 

[cm961]

And the schematic. Note that I scaled these by 50% so that I could post them. I can give you the circuitmaker files if you want them. You can get circuitmaker from ***** or their website.

Pete

 

[peranders]

soundNERD, have you missed Thomas Madsen's PCB?
http://www.diyaudio.com/forums/showthread.php?s=&threadid=19157

My looks like this
http://home8.swipnet.se/~w-80046/hifi_files/qrp/qrp01r0schema_p1.pdf
http://home8.swipnet.se/~w-80046/hifi_files/qrp/qrp01r0layout_cp.pdf

 

[soundNERD]

Thanks for all of the responces.

This project has been put off for now, since two people have asked me to build them a headphone amplfiier like the one i built using the lm4881 chip and i am working on my 300W subwoofer using the B/P LM3886's. I figured i would ask now so when I get to it i would have the pcb.

Just wondering, has anybody done what I want to do, using 2 x 2 lm3886 in bridged mode?If so, has anybody designed a pcb just for that?

Thanks for your help, though, Mike

 

[peranders]

Just wondering, has anybody done what I want to do, using 2 x 2 lm3886 in bridged mode?If so, has anybody designed a pcb just for that?

.... you don't seem to have checked Thomas Madsen's pcb...?

 

[Optical]

.... you don't seem to have checked Thomas Madsen's pcb...?

I think he wants a pcb he can make himself.... I do!
Thomas Madsen's pcb sure is nice, but i cant use it myself so its no more than eye candy..

 

[soundNERD]

First, yes i did look at his pcb. I need a 4-chip stereo amp, not a 6 chip mono amp.

And yes, it has to be one I can make.

 

[peranders]

First, yes i did look at his pcb. I need a 4-chip stereo amp, not a 6 chip mono amp.

And yes, it has to be one I can make.

Do you mean a pcb with 8 LM3886, each channel is bridged? Why can't you buy 2 pcb's from Thomas? I'll guess your project costs rather much anyway?

Note: Thomas pcb uses only 4 LM3886.