Greetings all!
As a service technician, I'm called upon to fix *noisy, clunking*
Imported (read Korean) grand actions. Most of these instruments are no
more than 5 years old. Most of these instruments are Samick SG series.
Simply put, when the keys are released, they return with a clunk like
a log being dropped.
I've worked out a service regimen to assess this problem.
1) Keyframe bedding - I've sometimes found the frame glides
dialled up excessively, or not at all. Fixes some of the clunk.
2) Balance rail holes are too big - front to back motion in keys. Sizing
the hole (water-soluable glue, or good old fashioned spit). Fixes some of
the clunk.
3) Back rail cloth too dense. Fluff it up with wire brush or needles. If
done carefully (i.e., not excessively) the key level is unchanged. Fixes
some of the clunk.
4) Wip felt (and jack reg. button felt) too dense. Fluffing with needles
helps, but at the cost of raising the hammer line. Jack button felt can
be accessed through the rep. window with a needle held in a pin vise.
Fixes a fair amount of clunk.
5) Knuckles too hard. I've experimented with replacing an existing
doeskin knuckle with a Renner doeskin knuckle (slightly smaller, BTW).
The difference was a considerable reduction in noise. Now, replacing all
the knuckles would be unfeasable (unless the client wants to spend the
$$$ "... but I just bought it *new*, why is it having these problems?")
I've had some success lightly scuffing the knuckle surface with a brass
wire brush. Nap direction remains unchanged. Fluffier knuckle = less noise.
6) Repetition springs too strong. A common problem on brand new Samicks.
Coupled with dense jack position button felt (the little regulating
assembly that sets the jack placement re: the knuckle), this can make a
loud *whack* when the jack returns to rest. Kudos to Glen Hart
for cutting my time in half on this job. Fixes a little of the clunk.
Has anyone else encountered this problem, and what do you think of my fixits?
(you did *what* to the knuckles?!?)
Any comments, questions, replies would be eagerly anticipated.
Rob Kiddell 8-)
Edmonton, AB. Canada
... If at first you don't succeed, get a government grant.
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