Are there any preamps that can work with 2 amps and a sub woofer?


I have a Krell sub woofer and 2 Llano trinity amps powering my speakers.  I'd like to know the best way to have 1 volume control over the whole system.  Currently I have to control the sub separately (manually).
Does any preamp allow 3 outputs?   Is there a better way?  Should a go with a good preamp and just split the output?
Thanks for any ideas.
ernie00
I use the freya+ to power and control volume for  2 amps, a powered sub, and have 1 output leftover. I love it. 
Just get 4 of these and plug to together to give 3 outputs, and tryit you won’t hurt anything, don’t do it if your preamp is a tube it'll run for the hills.
https://www.wish.com/product/5b0d6b80c0d6f4651b819647?hide_login_modal=true&from_ad=goog_shoppin...

Cheers george