I have an ADDAC 102 voltage control radio module and it has not gotten much use, so I had an idea to add some spark. They sell these cheap FM wireless transmitters that are pretty cool and pretty cheap. They contain a Li-Ion battery and are USB rechargeable. I switched out the mic with a plug, added a 250K trimpot and now I can use whatever source I want to bring in an out of reception. I might make a couple of them just for different sources using a sequencer. Anyway it has brought back life to using my voltage controlled radio!
Source for the transmitters.
https://www.ebay.com/itm/Portable-FM-Wireless-Microphone-Headset-System-with-Transmitter-Receiver-Black/163917539831