SergeModular

I can't think of a way to do this, so perhaps there isn't a way, but
I thought I would ask here just in case someone had some ideas.

I want to be able to send 16th note triggers to a TKB, and then
somehow use one of the rows in the TKB to turn steps on or off (ie.
not trigger the envelope that modulates the vca when I want a rest).
This is really easy on the MAQ, you just turn the knob all the way
to the right. But I can't figure out how to do this on a TKB. I know
i could turn off steps by just not sending a trigger to the TKB for
a step that I want a rest on, but I'd like to be able to do
everything from the TKB, rather than reaching between a TKB and a
drum machine or something while writing sequences. I've also tried
using one of rows to modulate the VCA, but I'd rather have an
envelope do that to get some definition to the sound. I have most of
the Serge modules, but I don't have any logic modules. Any way of
doing this without a logic module? I tried using a row of the TKB to
turn the envelope on or off, but the TKB voltage stays on too long
so you can't trigger consecutive steps.

Any ideas?

Thanks