rema: 730; Arietta

I have model with labeled Rema Arietta 734.

DC voltage on the speaker output is -24V(collector of the output tranzistor) what is the maximum voltage measured in the whole circuit.

the output electrolytes is likely shortcuted but I am confused because it works on old speker full powered without issues.

Any ideas?

Thanks

To thank the Author because you find the post helpful or well done.

Just understand how it works. The speakers make connection from supply line to the collector of split phase tranzistor and bring ref, voltage to the output circuit! So when Rema is powered without speakers there is -24V supply voltage on the one pole of speker terminal. Connecting speker will make bang! and turn on split phase tranzistor in order to get voltage ballance, Than comes music.

When is speaker already connected, powering on will bring music without banging becuse speker floating on the same potential on the poles -24V, no differntial of poential between termunals, no DC voltage.

Save as milk.

Great sound circuit with power supply noise reject.

DDR rocks.

To thank the Author because you find the post helpful or well done.