Technical Library

ACTION XI: Evaluation

Entire Contents Copyright © 2011 CBH
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Evaluation…
Some guidance might be helpful for tuners and technicians evaluating a harpsichord before working through the action to make it play as best it can. Certain things need to be checked, and for the most pleasing result, the processes are often best carried out in a logical order. It can be appreciated, for example, that if the staggering of a harpsichord is not consistent, there is little point fiddling around with jack height or quill cutting in an attempt at correction if odd jacks are in the wrong register slots and not returning correctly, or the quills have never been cut to ghost.

Advice on many of these areas can be found on this website. When—and only when—all these items have been considered and if necessary corrected, it is worthwhile concentrating on possible refinement. It is then the final careful work that can make the now-functioning instrument reveal its potential as good or even great.

The following points may also be of use to musicians when considering an instrument for purchase.


STRUCTURE Is the structure sufficiently strong to support the string tension?
Is the case noticeably distorted?
Are the tail and bentside hitchpinrail joints with the case in particular integral?
Is the soundboard excessively deformed?
Are there serious soundboard cracks?
Are there any issues affecting the longevity and/or preventing the usual operation of the instrument?
Warning 1K gif ALWAYS ATTEND TO IDENTIFIED
STRUCTURAL INADEQUACIES FIRST.
 
 
PINNING Is the instrument consistently pinned (angles, height, location…)?
Is the backpinning angle sufficient without being too severe?
Does the backpinning extend for a suitable section of the compass?
Are the strings evenly spaced from the face of the jacks?
Are the tuning pins evenly spaced and leaning slightly towards the player against the pull of the strings?
Are the tuning pins adequately tight in the wrestplank without binding?
Are the tuning pins all of reasonably uniform height?
Warning 1K gif A HARPSICHORD THAT DOES NOT KEEP
REASONABLE TUNE IS NEXT TO USELESS.
 
 
STRINGING Is there a string of appropriate gauge and material on every note?
Are the strings in good condition, or visibly corroded?
Are the hitchpin loops neatly wound and tight?
Are the tuning pin windings neatly done, each string leaving its pin cleanly without crossing over itself?
Is the downbearing from the nut to tuning pin consistent?
Is each string straight and hence solid in sound, or do they have an audible wave even when sounded individually?
Is the instrument at pitch?
Warning 1K gif AN INSTRUMENT MUST BE AT PITCH
TO BE PROPERLY JUDGED.
 
 
KEYBOARD Does each key operate freely without slop or excessive noise?
Are the keys uniformly balanced?
Are the playing surfaces tilted?
Are the keys evenly spaced?
Are the keys level?
Are the playing surfaces clean?
Is the keyboard in the correct transposition position for the present pitch of the instrument?
Does the transposition mechanism work as intended?
Warning 1K gif A KEYBOARD WHICH DOESN’T WORK OUTSIDE
THE HARPSICHORD WILL NOT WORK INSIDE IT.
 
 
REGISTERS Do the registers operate freely?
Are the register ON and OFF positions properly determined and reproducible?
Warning 1K gif PRECISE REGISTER POSITION IS PROBABLY THE
MOST CRITICAL ITEM FOR CORRECT OPERATION.
 
 
JACKS Is every jack present and complete?
Are the jacks numbered and in their intended slots, or have some been swapped around?
Does each jack return by gravity in the register without hinderance or too much slop?
Is there a tongue in every jack body?
Are the tongues consistently angled in each jack?
Is each tongue return spring functional and within the required tension range?
Do the tongues operate freely?
Are the jacks of consistent height?
 

Warning 1K gif

JACK HEIGHT CANNOT BE ACCURATELY SET
IF THE DAMPERS ARE INSTALLED.

 
 
QUILLS Is there a quill in every tongue?
Does each quill project from its tongue at uniform slight upright angle?
Are the quills of consistent material, shape and section?
Has each register been cut to ghost?
Have the quills been voiced?
Is the underside of each quill smooth and evenly graduated to thinner at the tip?
Is there a bevel on the underside tip of the quill to help it flip below the string?
Is the projection past each string consistent?
Do the quills rest a uniform distance below the strings?
Does every note play?
Is each choir even throughout its compass?
Do the choirs correspond with nice balance between them?
Warning 1K gif ACCURATE VOICING
TAKES CONSIDERABLE SKILL.
 
 
STAGGER Is the stagger predictable and consistent on each and every note?
Warning 1K gif A POORLY STAGGERED HARPSICHORD
IS DIFFICULT OR IMPOSSIBLE TO PLAY.
 
 
REPETITION Does each note repeat reliably at reasonable speed?
Does each quill return below its string, even when the note is released slowly?
Warning 1K gif A HARPSICHORD IS A MACHINE
AND MUST WORK RELIABLY.
 
 
DAMPERS Is there is a damper in every expected jack slot?
Are the dampers made of suitable material in good condition?
Are they at the required height in each jack for correct operation?
Do they retain their position in the slot without deforming the jack?
Are they trimmed to avoid interference with adjacent strings?
Warning 1K gif DAMPING IS INSUFFICIENT
IF YOU CANNOT ARTICULATE.
 
 
JACKRAIL Is the jackrail firmly fastened to the case to avoid noise?
Is it the correct way around?
Is there sufficient and appropriate cloth padding on each choir?
Are the jacks of each choir stopping at the required limit, or are they bouncing?
Is the keydip sufficient and uniform from key to key?
Warning 1K gif IF THE JACKRAIL IS NOT CONSIDERED
ALL THE PREVIOUS WORK IS WASTED.
 
 
FINAL VOICING When all the above items have been attended to, the instrument is working
and it is then possible to consider its final refinement and subtlety.
 



Movie thumb 3K jpeg Movie 1K gif Harpsichord triage
Carey Beebe diagnozing and rectifying an Institutional harpsichord in limited time.
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