Mastotron Subs on a Footswitch?

[joeychickenskin]

Hi

I'm looking to build from a Mastotron layout and was thinking that if the volume remained perceptively constant or raised slightly with subs engaged, that subs could be on a second footswitch with the two caps for subs 2 and 3 on an toggle for that option to allow introducing subs mid-song.

Has anyone built one who can say if there is a noticable to-ear volume change with the subs engaged?

Thank you