I goofed.  My first posting on this topic started out okay, but then
it obviously went terribly wrong.  My comments about recut rolls
usually causing the problem are correct.  But when I launched into
the discussion about clogged bleeds, my brain was completely dyslexic.
That discussion is relevant to poor repetition due to "rapid on, slow
off" of the note caused by clogged bleeds.  So far, people correcting
my error have been kind, but I am none the less embarrassed for making
the blunder.

So, adjusting my thinking, I will again venture a comment about the
issue first mentioned by Danny Wilson.  If the note flutter is not
caused by a poorly cut roll, examination of the pouch bleed might be
in order.  If the bleed is too large that might be the problem, but
bleeds usually don't become too large all by themselves.  There are
certain things that can happen to the Duo-Art bleed strip that has
the effect of making the bleed too large.

Thirty years ago, Mel Septon identified a problem with Duo-Art
bleed strips.  These strips are made from solid maple which has been
drilled and channeled to form the bleed strip.  Mel discovered, much
to everyone's surprise, that the maple used in these strips is really
quite porous even though the strips don't have any visible evidence to
suggest that porosity.  The problem is easily corrected with shellac.

When the porosity is present in the bleed strip, there are small leaks
that connect the individual note nipples to their adjacent neighbors.
This can result in a very sluggish "note on" event.  This is because
the note sheet hole now must overcome the corresponding bleed, plus
the leakage from its neighbors.  In effect, this is like having an
oversized bleed.

Other issues that might cause key flutter during chained holes are
obstructions in the tubing between the tracker bar and the bleed strip.
Kinked tubes, gasket holes that are too small, and clogged nipples
would be an area to check out.

Sorry about the previous posting that was partially in error.

Bob Taylor
Missouri