Hi,
If I understand you correctly, you want to plug your mic into a mixer, but be able to send that mic signal to two different arranger mic inputs at different times, right?
I take it that the outputs of the arrangers are also going through the same mixer, correct?
And the output of the mixer is going to an amplifier and speakers. "?"
One way to do this is to use a Mackie 1202VLZ mixer. The VLZ models have a cool function that when you mute a channel, the signal is routed to an alternate stereo output. So you could plug in both arrangers into stereo channels and plug your mic into a mono channel. Use the normal (un-muted output to go to your amp/speakers. Take the left alternate output of the mixer and plug it into one of the arranger mic inputs. Take the right alternate output of the mixer and plug that into the other arranger mic input. When no channels are muted, your mic and both arrangers would be sent directly to the amp. When you want the mic to be sent to one of the arrangers, simply mute the mic channel of the mixer and use the pan control of that channel to direct the mic signal to either the left or right alternate output. The mic signal would then be processed by the appropriate arranger and then get back into the mixer and out to the speakers via the arranger�s stereo output.
Here are several links to the Mackie site showing pictures of the specific areas of the mixer for help in visualizing how this could work.
Channel Strip:
http://www.mackie.com/home/showimage.html?u=/products/1202vlzpro/images/1202ProChStrp.jpg Input/Output Section:
http://www.mackie.com/home/showimage.html?u=/products/1202vlzpro/images/1202PROTopIO.jpg Rear Panel:
http://www.mackie.com/home/showimage.html?u=/products/1202vlzpro/images/1202PROBack.jpg There are surely other mixers out there that have a similar function, I am just familiar with the Mackie since I have a 1402 VLZ Pro that I have used for a long time and it has been very good. Clean output and reliable.
Best of luck,
Dave McMahan