My first guess might be a helicopter going by. Hard to really be useful without a more detailed description of the "whirling noise" that you are hearing. It is more like a hum or whine? Does it come and go with the blinking of the LEDs? Does it only happen in connection with one of the LEDs? Or both?
Is your input wire running near the LFO? This one is pretty sensitive, try routing the wire as far away from the PCB as possible and see if that helps.
Is your input wire running near the LFO? This one is pretty sensitive, try routing the wire as far away from the PCB as possible and see if that helps.
My first guess might be a helicopter going by. Hard to really be useful without a more detailed description of the "whirling noise" that you are hearing. It is more like a hum or whine? Does it come and go with the blinking of the LEDs? Does it only happen in connection with one of the LEDs? Or both?
This is most probably from the wire collecting the noise from the LFO.
Try moving the wires while the pedal is on and see if it changes the noise.
Better use shielded wires to solve this.