Audio driver board

[luigidedom]

On these boards which resistor is changed to make protection less sensitive

 

[JonSnell Electronic]

Circuit?
Make?
Model?

 

[Perry Babin]

R30

 

[luigidedom]

Sundown 3500

 

[luigidedom]

Perry, Increase or decrease value of R30?

 

[Perry Babin]

Are you sure that you want to make the protection circuit less effective?

If you lower the value, the threshold for shutdown will be lower (it will shut down sooner). Increase the value to make the amp less reliable.

 

[luigidedom]

The amp is being used purely for spl it shutting down just before the end of the roll so just need to increase that threshold. R30 on this amp is 3k9 I see on some other similar boards its 4k7

 

[Perry Babin]

390, not 3.9k

 

[Perry Babin]

Side note... The resistor value AND the shunt resistor value determine the shutdown. You cannot compare the value of R30 to other amps unless they use the exact same shunt resistors. Even then, if the output configuration and rail voltage are different, the value of R30 may be different.

Increasing its value will do what you want but you should tell the owner that here is a risk of much greater damage if/when the outputs fail.

 

[luigidedom]

Correction yes 390 and 470 and yes the owner is aware of the consequences. I have told him to check the impedance at the frequency and that his box or port is more than likely the problem and not the amp. But you know these spl guys know it all when it comes to box design......