Anyone used the BA6138 square law VU meter amplifier chip?

[stellavox]

Got the Chinese board with this chip on it. Meters work OK with normal program material but with little or no signal, the pointers
"bounce around" their rest position, like noise is getting in. Suggestions?

THANKS

 

[stocktrader200]

Bad capacitor or noisy power possibly.
Mine is done passively with diodes powered from the power amp

 

[kevinkr]

Low frequency noise?

 

[NareshBrd]

Try filter caps, non polar.
A few pF should be enough, whatever you have lying around, good for 25V at least.