By Steven Wasser - President, Verne Q. Powell Flutes, Inc.
Flutes have come a long way in the last 100 years,
yet many musicians prize old Louis Lot, Haynes, and Powell flutes. Flute scales are better today, precision
machining produces superior parts, synthetic pads are more stable, and silver
is silver – or is it? Does something
happen to silver over time that could have a beneficial effect on sound? In fact silver does change over time. It stress relieves and age hardens.
|Steven Wasser giving tour of Powell production facility|
When any metal is worked, such as by cutting,
extruding, or bending, it becomes stressed.
In its “relaxed” or unstressed state, the molecular structure of metal
looks something like graph paper, with a nice, regular geometric
structure. When the metal is stressed,
some of those boxes get scrunched up, and some become bigger and
misshaped. As a result of these
irregularities the metal is unable to vibrate as freely as it would do in its
pure, unstressed condition. These
irregularities can cause dead spots in a flute.
In our experience resonance is better with silver that has been stress
Hardness correlates with stiffness or
rigidity. When metal flexes it absorbs
or diffuses energy. Since flutes are
very inefficient at converting your air into sound, small differences in how
that air energy behaves can affect acoustical output. We believe that the slight age hardening of
older silver flutes has a positive effect on response.
Does anything else change over time with older
silver flutes? Well, yes, the instrument
is subject to daily vibration from being played and is swabbed. We cannot document what effect, if any, might
arise from these activities, but some flutists are convinced that they make a
Is there a way to produce some of the effects of
aging on silver in new silver flutes?
Yes. At Powell we use a variety
of techniques to keep the molecules of the flute body as even as possible. When we solder we generally heat the entire
body at once, evenly, rather than spot soldering one location at a time. And when we’re done, we cryogenically treat
the entire flute. There is solid
documentation that cryogenic treatment age hardens and/or stress relieves certain
metals, but data for the effect of cryogenic treatment on sterling silver are
inconclusive. Based on years of
subjective testing we believe cryogenic treatment stress relieves silver and
slightly age hardens it.
Some of the qualities of older flutes may also be
perceptual rather than real. A number of
years ago one of our customers was complaining that new Powell flutes did not
have cups properly centered over the tone holes. I was surprised because we use gages that are
accurate to within the thickness of a human hair. Then this customer came with Powell flute
#2000 made by “Mr. Powell” which he proudly showed me. As I looked at this flute I noticed that the
trill cups were severely bent – nearly 1/8”.
Apparently when Mr. Powell made this flute the trill cups were not
centered properly. Rather than re-make
the keys he simply bent them so that they covered the tone holes. When I pointed this out to the customer he
was shocked. He somehow noticed if our
new flutes cups were off center by 0.003”, but never noticed that the trill
cups on Powell #2000 were grossly off center.
Beauty is in the eye of the beholder. We have thought about the way flutes age and
have tried to mate a process for aging the flute with modern elements like
improved scale and keys.