[SCCC] phones and external speaker

[w6now]

I have a MarkV.
I plugin my headphones to the front "Phones"
I have an external SP-8 speaker that plugs in to "Ext speaker" on the back

I'd like to have the ability to send audio to both sources at the same time (headphones ON, Ext Speakers ON).

Why? My son comes in the shack, and I'm working DX on CW - I'd like for him to hear the pileup while i keep the cans on. 


73!