Electronic Sound of steam

I’m guessing the topic was closed because it was in the wrong place, so I’d like to continue here. I apologize ahead of time if this is not right.
I am trying to turn off my SOS from my tender, yet keep the whistle. I do not have a switch on the tender. I unplugged the white wire to the engine. Still sos. I unplugged just the yellow to the loco. No power to the tender. I turned both items I am pointing to with the blade thinking one might be sos volume, the other whistle volume. No luck, they just change the pitch and frequency of the whistle. Is there anything I can cut or disconnect to disable sos yet keep the whistle?