RE: [Harp-L] retuning chromes

[Winslow Yerxa <winslowyerxa@xxxxxxxxx>]

Phil Lloyd wrote:

Is there a web site or document that explains the reed plate layout for

various chromatic harps.

I want to retune some chromes in a combination of half valved
bebop/Richter tuning. Are all solo tuned chromatics set up with blow
plates/draw plates to allow Richter bending on low end after removal of
valves on blow notes?

====================Winslow replies:

Most slide chromatics use Knittlinger construction. In this
construction, the comb divides each hole into an upper and lower half.
Each upper hole contains a blow and a draw reed mounted side by side on
the upper reedplate, while each lower hole contains, again,
side-by-side blow and draw reeds, this time mounted on the lower reed
plate.

Richter, by contrast, has no hole divider. All blow reeds are on the
upper reedplate, and all draw reeds are on the lower reedplate. BLow
and draw reeds still share a hole but they are mounted bottom and top
instead of side by side.

There is no such thing as "Richter bending." I think you mean dual reed
bending, where the blow and draw reed cooperate to produce a bend
provided that valves do not prevent one of the reeds form receiving
air. It does not matter whether the reeds are top and bottom as in
Richter construction or side by side as in Knittlinger construction
(they don't even have to be in the same holes, as long as they can be
accessed by the same breath stream - that's why the Discrete Comb and
the XB-40 work).

For dual reed bending on a chromatic you need to focus on the
side-by-side blow and draw reeds that share a hole. For instance, on a
Hohner 270 chromatic in C, Hole 5 will contain a blow C and draw D
reed. These will be located on the upper reedplate. 

To allow for a dual reed bend on D, the C blow reed needs to receive
air during a draw note. This requires that you remove the valve that
blocks draw airflow to the C reed. This will be mounted on the outside
of the reedplate over the C blow reed slot. 

The same will apply to the holes containing E-F and G-A.

However, in the hole that contains C and B, the blow note is the higher
pitched and therefore the one that will bend in a dual reed system.
Consequently, to enable a dual reed bend you would remove the inside
valve from the B reed slot.

I should point out that in the case of F and of the C that is paired
with B, you wil get more bending range with a valved bend (several
semitones) than you will with a dual-reed bend (less than a semitone).

The issue is complicated by the issue of straight and cross tuning.

On a straight-tuned chromatic, all the reeds for the C scale are on the
upper reedplate, and all the reeds for the C# scale are on the lower
plate.

Straight-tuned instruments include the Hohner 270 (including Toots and
Larry Adler 12-hole models), all Herings, Huangs, and some Suzuki
models.

On a cross-tuned chromatic the position of reeds for the C scale and
the C# scale alternate between the upper and lower reedplate for each
successive hole. For instance:

UPPER: C  D  | E# F# | G  A  | C# B#

LOWER: C# D# | E  F  | G# A# | C  B

I don't claim this is literally accurate in all details (the reeds may
be arranged Draw-blow instead of blow-draw: top-bottom locations may be
reversed, etc.). HOWever, it demonstrates the principle.  You can
easily determine the pitch of a reed by plucking it. Use the
information gained to draw a map of reed locations. Looking at the
pattern of the holes in the slide will also give you orientation.

Cross tuned instruments include all modern (since about 1955) Hohner
16-hole instruments, the CX-12, CBH, Suzuki Chromatix series and
others.

What about models I hvaen't mentioned? Look at the small holes inside
the nmouthpiece holes. If all the open holes are in a straight line,
it's straight-tuned. If they alternate between top and bottom in a sort
of checkerboard patter, it's cross tuned.

Winslow


		
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