lm3886tf, Dc at speaker output....

Status
Not open for further replies.
The high rail voltage is probably not causing the output problem. At +/- 45 V you will need a VERY big heatsink. My guess would be 3 to 4 times bigger than at +/- 22 V. Look how close the two chips are placed. This will again double the amount of thermal energy.

The ground loop breaker (R6) as used here is asking for problems like negative rail at output. The resister fails and your speaker goes up in smoke.

When you draw a single channel schematic, you may not see the interaction of the two channels. With this design both of the feedback currents (L+R channel)
flow through R6 or even worse the current may find an alternative route.
 
Last edited:
Picture where you can see the SMD resistors from input to GND.

Regards
zoky2
 

Attachments

  • lm3886.jpg
    lm3886.jpg
    128 KB · Views: 112
ok, thanks everybody.
now i seen my mistake,
When i did my board with potenismeter, it was a short in the audio input,
so i did not connect any potensiometer at audio in so zoky2 was totally right here,
I had all volt on speaker out, but now when i put 20k ohm on both signal in to gnd,
it work.. 🙂
thanks for all help to everybody. 🙂
but +-44 volt work fine, but read that its better to lower voltage, so thats what up next.
 
Status
Not open for further replies.