The invention relates to a LED light source comprising: input terminals (K1, K2) for connection to a mains voltage supply source, a rectifier (RB) coupled to the input terminals for rectifying the mains supply voltage supplied by the mains supply voltage source and comprising rectifier output terminals, a DC-DC converter (CONV) for generating a DC current out of the rectified mains supply voltage, comprising converter input terminals connected to the rectifier output terminals and comprising a first converter output terminal (A) and a second converter output terminal (B), —a LED load (LL) with an anode coupled to the first converter output terminal via a current control element (D5) for blocking a current flowing from the anode of the LED load to the first converter output terminal, and with a cathode coupled to the second converter output terminal via a first controllable switch (M1) having a control electrode coupled to first control circuitry for rendering the controllable switch non-conductive in case the LED light source is in standby mode.