lm3886, advice before soldering

[dirtyblvd]

Thanks Mooly,
something like attachment could be ok?

 

[Mooly]

That looks fine.

 

[dirtyblvd]

Thank you so much!

 

[Mark Whitney]

Not the way I would layout a LM3886. Connect the speaker, feedback and Zobel as close as possible to chip pin 3 (output). Connect the speaker gnd, feedback/input gnd and Zobel gnd to the bypass capacitors on the amp board.

 

[dirtyblvd]

Thanks for the reply Mark,
following your suggestions my small pcb would be very populated, what are the drawbacks of the layout I posted?

 

[Mark Whitney]

The Zobel passes high frequency current. It is important that the circuit is low inductance and that the current not create error voltages elsewhere in the amp.

 

[jcx]

shouldn't be any significant audio frequency current in the RC Zobel leg, and it should be totally linear so even if Zobel current common impedance couples with a signal ground it should only give a small frequency response error

the RC should be close to the chip - the series L closer to the binding posts and if open/solenoid should be kept away from metal, especially ferromagnetic casework or hardware