Lionel MPC how to make Sound Of Steam locos work with SOS & whistle

Lionel sound of steam locos came with a low voltage circuit with a resistor that is incompatible with sound of steam & whistle tenders (makes the white noise stay on constantly) I found an easy life hack for making this 8304 set up for sound of steam only to work with the sos & whistle tender by simply snipping the low voltage circuit just to the left of the resistor on the smoke unit eliminating the compatibility issue. I bought this 8304 and it came with a nice B&O tender but the tender interestingly came with the whistle board. (the capitol limited set this most likely came out of had an 8304 locomotive but only had sound of steam.) How this B&O tender shell has the whistle board is anyone's guess, I suppose someone could have swapped shells with the Milwaukee Rd set that did have the whistle board and the 8305 that was set up to run with the whistle. I've only found two Lionel Atlantics that were set up for the whistle board, the 8305 milwaukee Rd and the 8204 from the Allegheny set. Some early Hudsons were compatible too. Now you can easily make any of the early mpc locos compatible by simply removing the low voltage circuit.