Class D amp not loud enough - Raspberry Pi Forums

https://www.adafruit.com/products/987
amp i'm using , don't know why not loud. have alasmixer turned 100% , tested audio jack on pi , played loud through headphones.
have wired this:
5v ----- vdd
gnd ----- gnd
sdwn ----- nothing have no idea port for
l+ ----- left sound output
l- ----- gnd
r+ ------ right sound output
r- ------ gnd
g+ ------ nothing don't know if for
g' ------- nothing don't know port for

using raspberry pi 2 , os retropie 3.7 if please thankful

first off, out of way, sdwn "shutdown" - if connect ground powers down chip. leaving unconnected ok, since there's resistor on board pulling 5v.

g , g' control gain of chip. there's resistor on board connecting them, can funky things, such turning gain maximum when pir sensor detects mouse close by.
it's easier control gain pins @ bottom edge of board.

headphones can sound loud in ears, speakers need put out bit of power sound same.
if haven't connected g, g', or of 18-15-12-9 pins, gain set default 6db - doubling voltage.

try connecting in turn, g or g' 5v or ground, , see if improvement

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