Dual lm3886 pcb

[wunbin47]

Single lm3886 Reference:
http://www.generalguitargadgets.com/
http://www.generalguitargadgets.com/...lm3886_amp.pdf

New modify for dual LM3886
http://home.pchome.com.tw/personal/p...4/Dual3886.doc

[gfiandy]

Whilst turning this into a dual layout you could fix the minor layout errors.

The design has shared copper going to C6 from V+ in. This means that the charging currents into the cap and the audio currents to the amplifer share this peice of copper. This may cause low level interference (hum) and could easly be solved by tracking to the cap and then on to C2.

Similarly it would be slightly better to go straight to C1, C2 and not have the small shared stub of track off the main path. (Although at this level it will probably be inaudible)

Also it would be better if the GND was tracked to the caps C5, C6 first so that the return path for the charging current is not shared with the return path for the star point. You need to use the same track length to each of the capacitors like it does going to the star.

However if you are just using this as a guitar amp there probably isn't any good reason to do any of this as the sound will be swamped by the tone of the guitar and the speaker drive unit you are using.

Regards,
Andrew