# Constant ~250Hz on output od class D amp (SL-A 1500)



## MyName (Oct 14, 2009)

I'm getting a constant ~250Hz sinus wave on the output of my class D monoblock (Sinus Live SL-A 1500 (same as board as Branson 1500.1, Climax Bullet 1500...).

Haven't taken it out of my car and started measuring anything yet, but does anybody have any ideas where to start? The only thing I could think could be wrong is that the power supply caps dried up (one has already failed a couple of years ago, the other one wasn't changed because I had a competition the next day and it was a quick fix).

The signal is present no mater what the input is or what the settings are.
First image is with no input (RCA's unplugged), the second is with a 50Hz test tone at moderate levels.


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