yet another lm3886 design

[geekysuavo]

hello all,

just figured i'd post my first design for an LM3886-based amplifier. the amp schematic follows the National datasheet for all practical purposes, and the power supply is an unregulated, snubberized supply. (8 ohm load)

amplifier, single channel:

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

power supply:

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

so here are my questions... i'm planning on using a 25-0-25 (RMS) toroidal transformer with dual secondaries. would a rating of around 250VA suffice? also, is the ~4.7uF DC-blocking cap at the inputs truly necessary? if so, is there any reason why i can't wire it point-to-point between the RCA input and the amp board?

the parts i've chosen for the boards are here: (digikey part numbers)
http://files.geekysuavo.org/gainclone/amp-bom.html
http://files.geekysuavo.org/gainclone/psu-bom.html

any reason i shouldn't be OK with a heatsink such as this one ?

also, if there are any blatant errors with the board layouts, i'm open to all forms of criticism.

thanks a bunch,
~ brad.