Finding a quiet suction box today is not a problem, particularly
if your player is easy to pump. The Player Piano Co., Wichita KS,
has greatly improved their Delux #650 vacuum kit so that the triac
control unit will start and run the vacuum motor at a very low level.
When these high speed motors are run at low speeds, they are practi-
cally inaudible. I was very pleased with the last ones I installed,
and can now confidently recommend them to anybody.
They are also more reliable as a result. The heat sink case of
the triac is now bolted to the control unit, which is a good sign.
I have more confidence in this, now.
When the player piano has leaky valves, such as old, partly dry-rotted
leather on the inside valve poppets, then you will have to run the
suction box at higher and higher speeds to play the piano, and the
turbine scream cannot be controlled easily.