by Hendrik Broekman
Let us start the discussion by saying that since its selection
was driven by the need to satisfy the perceived requirements of our own times, we consider
Delrin to be an entirely appropriate material for use in contemporary harpsichords by
contemporary players. In this sense it is not at all anachronistic. That it sounds
virtually identical to crow quill is the cream on top of the milk.
To the novice, the difference between jacks voiced in crow quill and
jacks voiced in Delrin is insignificant and easily missed. To the initiate the difference,
though inexpressible and equally easily missed, is profound. All other things being equal,
we regard the difference between listening to crow quill and Delrin as irrelevant for the
simple reason that the effect is negligible and all notes are affected equally. But that
assumes that all things would be equal which they seldom are.
Crow feather is almost always found in wooden jacks. Delrin is almost
always found in plastic jacks. While we do not believe that the choice of jack material
has any bearing on the musical sounds produced by the wire and amplified by the case, the
largely subliminal extra-musical noise that accompanies each pluck is, due to the vastly
different acoustical qualities of the two materials, very different, and the sounds of
umpty-umpt jacks jumping up and down, each rattling its own unique rattle and clicking its
own special brand of click, is cumulative.
The result, in our view, is that (again all things being equal, the two
actions regulated identically) instruments with wooden jacks project less of this
extra-musical noise and have a clearer voice when listened to at close range. The effect
is observable in inverse proportion to the distance from which the instrument is heard or
the volume of the surroundings. Any discernible difference virtually disappears in
moderately large quarters.
Are plastic jacks unlistenable? Not by any means. It is not the
listener, but the player who stands to gain the most from choice of plectrum material.
Again, both choices are potentially correct and it all depends on what it is the player
may be seeking.
First, who listens most and closest to the instrument? - the player.
Score one for crow quill. Second, who cares the most about the day-to-day reliability of
the plectrum material? - the player. Score one for Delrin. It goes on in this fashion. The
two materials each have vices complementary to the other's virtues. The three major areas
of concern (and these overlap greatly) are touch, inconvenience and what for lack of a
better word we will call comfort.
The touch of the two materials differs in much the same way that the
sound differs, only the effect is a little more noticeable and is, of course, inescapable.
Some claim that the resistance curve varies between the two. Having no data to the
contrary we would not dispute this assertion. It should be enough to say that the two
materials differ in a je ne sais quoi kind of way. We find well set-up instruments
quilled with either material equally comfortable to play.
Because of the divergent structure of the two materials at all levels,
neither will tolerate being cut to mimic the other. Consequently, the shape and
functioning of the two sorts of plectra during the pluck will always differ in predictable
Quill tends to bend as if hinged near its base. It usually gives fair
warning of its impending failure by becoming noticeably softer than its neighbors. Delrin,
however, cannot tolerate the concentration of flexing in one area; the misery has to be
dispersed over the greatest possible area or else the area most flexed will work-harden,
ultimately breaking there quite cleanly and suddenly.
For Delrin, an even
taper from base to tip produces the longest-lived plectra. Because of
Delrin's habit of hardening due to flexing as well as to exposure of
the surfaces to air, the touch of well-used harpsichords voiced in Delrin
gets progressively heavier - all other regulation kept constant, of
course. The effect is gradual and not particularly noticeable on a day-to-day
basis. The jacks may be backed off slightly to keep the general effort
level within bounds.
Crow quill plectra can individually display great resistance to
plucking, not because they harden, but because the surface becomes so rough that it will
not allow the string to slip off. If left uncorrected, this will cause the plectrum to
over-bend and will hasten its ultimate demise. For this reason it is necessary to mildly
lubricate the top surfaces of crow quill plectra regularly as well as individually
whenever one begins to get loud.
It is fair to say that a well cut suit of Delrin plectra will outlast an
equally well cut suit of crow quill plectra by a factor well in excess of two. It is
unlikely that a suit of crow quill will last more than two or three years before its first
broken plectrum. In contrast, it is quite typical for the original cohort of Delrin
plectra to last five to ten years before first breakage. This is a good long time to
forget how to cut plectra; whereas, with crow quill one tends to keep in very good
practice. We have to admit that we hear of more people jettisoning their crow quill and
switching to Delrin than the opposite.
Our view of comfort is that the harpsichord owner should be comfortable
with all aspects of the choice he makes. He should be able to accept the vices and virtues
of the material and be at ease with the demands which the material will make. Since there
is so much unsolicited opinion lurking about, he has to be clear about and comfortable
with the reasons for his choice.
I have not yet decided how I will quill my next instrument. I tend to
think it will be crow quill (again), but the constant playability of Delrin looks awfully
appealing after the last sixteen years.