Celeste Regulation

[FSSturm@aol.com]

I agree with Ed Foote that celestes aren't that hard to figure out, though
Newton Hunt is also right in suggesting that the results of the finest and
most meticulous work are not real satisfying. The ones I have worked on
(belonging to the local symphony and the university) were by no means a joy,
but I was able to improve them quite a bit.

First is the question of how the tone bars are suspended (or held in place).
On one of the ones I did, they were held by two screws run through holes in
either end of the bar, with some sort of bushing to keep the bars from
rattling against the screws. The bushings were hard as rocks or missing, so I
replaced them. I seem to remember that player piano tubing worked, or perhaps
I had to find a different thickness. For that, consult with percussion people
- this part of a celeste is the same as a glockenspiel more or less.

The action itself is a downward striking one - sopmething piano makers tired
for years to make work, and finally gave up (for good reason, I think). Basica
lly, there is no escapement. What happens is that the hammer is pushed down
against the resistence of a fairly strong return spring. Adjust it so that at
the bottom of keydip the hammer is quite close to the bar, but no so close it
will bobble or block if the player presses the key down quite hard. Momentum
carries the hammer that extra 1/4 inch or so to strike the bar. There is no
check.

Adjustment varies with the style of instrument, but is obvious. One that I
worked on had a sort of drop sticker arrangement. The other had wires with a
couple of wire nuts on them - the sort that slides up and down the wire until
you tighten a set screw through its side. You adjust these nuts or drop
sticker arrangement to set "blow distance", which is really just how far the
hammer hangs above the bar when the key is at rest.  Then adjust keydip so
the hammer will come close to the bar when the key hits bottom. (Samples
first to arrive at resonable specs). Keydip may be altered a little from key
to key to "fine tune". I don't think the player would notice somewhat uneven
keydip, as the action has such a different feel from a piano.The
"hammershanks" of the ones I did were fairly stout wire, and could be bent
for "fine" adjustment.

Dampers are a bit problematic. It's hard to get them all to bleed the same
amount (a better description than getting them to damp). It's a matter of
fuss, fuss, fuss, not unlike working on grand dampers but much less rewarding
in the results. They need to touch down at the right point on the bar, which
sometimes varies from one to the next. Also need to be aligned so they touch
down squarely, which sounds easier than it is.

Bushing keys was a big improvement on the ones I did - just about the
sloppiest I had ever run into.

After everything is kind of working, you can try to even up the touch by
altering spring tension and whatnot. And then try to "voice", which is quite
a can of worms. It seemed that the hammer's condition very little effect on
tone production compared to how the tone bars were suspended, and the
condition of the tone chambers. I just fussed to the point of diminishing
returns.

A couple other notes: 1) you need an extra long screwdriver to tighten/loosen
for adjustment the damper flanges. Extra long as in 18 inches or more. 2)
Since the tone bars are much wider than the key, they are set on three
levels. This means the damper pedal arrangement must raise three levels of
dampers simultaneously. Also, neighboring keys don't play neighboring tone
bars - a little disconcerting at first, but you get used to it.

Hope this is helpful and not too confusing and offputting. I suppose that
somewhere there must be someone who specializes in overhauling these things,
and would be happy to learn who if that comes to light. Meanwhile, thoswe of
us facing marginal budgets and needing to "make it work" can be assured that
if we can regulate a grand, we can surely figure one of these out enough to
improve it.

Regards to all,
Fred Sturm
Albuquerque, NM