Sub with Levinson 380 integrated

Do you mean Levinson 383 integrated? It has no pre-out, your only option is speaker level connection.

I did mean the 383.  I had been reading about the 380S preamp, and inadvertently carried that designation over.  The 380S does seem to have a variable that might be used to drive a bass manager.

What kind of sub do you have?

I'm using a pair of Velodyne HGS-10s with an SMS-1 bass manager for the setup in which I had proposed to use a 383.  The KEF LS50s are surprisingly good even without a sub, and can track a jazz bass pretty convincingly.  My main setup does the organ pedal notes convincingly without .

Does a Levinson 380S preamp provide an output that can be used by a bass manager that controls subs?  It appears to have balanced and single ended outputs, both I assume with volume control.