Dear all,  Following a few recent interesting posts on this subject,
I have had the same issue with my Brinsmead Higel, which lives at the
bottom of the garden in my shepherd's hut.  When I purchased the piano
several years ago, it had mounted in the bottom of the case, a suction
box made up from an elderly vacuum cleaner motor and a simple speed
controller which was obviously home made.

The first thing I did was move the suction box out of the piano and
into a belly box mounted under the hut.  I was beginning to get nervous
about fire risks in the back of the piano, etc., and this seemed to me
to be the obvious solution and also the motor noise was reduced to an
acceptable amount.  It sits in there along with the garage breaker
which controls and protects the 6 amp and 16 amp circuits.

It was permanently and securely "plumbed in" by using rubber hydraulic
hose and domestic black plastic solvent weld fittings which are
concealed from view and run through the floor and behind the piano.

I found the electronic speed control as fitted, a bit restricting, as
it wouldn't reduce the vacuum far enough in the summer; eventually
I hit on the idea of a large variable pneumatic "bleed".

I fitted a plastic standard domestic waste, swept, 22 mm "T" fitting
into the pipe which connects to the reservoir and the other part of
the "Y" connection is connected to a standard 22 mm brass gate valve
mounted conveniently to hand on the wall of the shepherd's hut.  This
is connected to outside via a 22 mm hole and a further length of 22
mm copper pipe directs the exit downwards to the ground outside,
thus eliminating any exhaust noise that might have been heard inside.
For me this device works perfectly and half a turn to open the valve
is okay in winter whilst in summer it's more likely one and a half
turns.  The point is that it can be varied to suit.

I do actually regularly alter the vacuum to suit the music in play.
It may sound a bit silly but I always play a few bars of the same roll
each time I fire it up and this easily, after a bit of experience,
allows me to set the nominal vacuum to an acceptable level.  My test
roll is "By the Light of the Silvery Moon" which has a very quiet
introduction, to test out the vacuum level and is a 10-second job
initially.  Some rolls need no further adjustment in play, others do.
One example of one that does is Ascher's "Alice Where Art Thou", which
needs a large amount of suction right at the end, when you reach all
the reiterating notes!

I know that if I pedalled it I wouldn't need any of this but like many
other fans of player pianos, I suspect, my dodgy back won't let me!

Hope this of interest!

Best regards and Merry Christmas!

Peter Clarke

 [ More information at "History of the Shepherd's Hut",
 [ http://www.shepherd-hut.co.uk/history.html  -- Robbie