Adding a sub to 801a

[chujk1985]

Looking for a little guidance in adding an amp to power a sub in my 801a.

There are a lot of posts with the upgraded stereos in 802a's, but I cant find much on wiring a line out converter or any other solution for a standard stereo in an 801a.

Sorry if there is other info out there and am just not finding it.

Thanks!