Re: [Harp-L] XB-40 bending (adjustment and service instructions)

[Rick Epping <rickepping@xxxxxxxxx>]

>
>
> Hi Robert,

The XB-40's regular reeds (inside blow reeds on the top plate and outside
draw reeds on the bottom plate) should be adjusted in their curvature and
gap as with reeds in any other harmonica.  The enabler reeds (outside draw
reeds on the top plate and inside blow reeds on the bottom plate) should
have no curvature whatsoever and lie flat above their reed slots with
almost no gap - say, only about 0.1mm gap at the free end.

There might also be a problem of air leakage between the mouthpiece and
comb assembly.  Below are some instructions for servicing the
mouthpiece/comb assembly if you have problems with noisy or sticking
valves.  The reassembly instructions that follow are very important, as any
air leaking from under the mouthpiece can adversely affect reed performance:

Mouthpiece/Comb Assembly Service Instructions:

Before you dismantle the mouthpiece/comb assembly you might try cleaning
it, which it requires from time to time anyway.  Remove the covers and reed
plates.  Note that the plate screws for the back of the harp are longer
than those at the front.  Leave the mouthpiece screws in place.  Then soak
the entire mouthpiece/comb assembly in warm water with a little dishwashing
liquid for about half an hour.  When you first immerse the assembly,
carefully raise each valve with a wire or some such tool to release any air
bubbles caught inside the comb and to let the water in between the valves
and the comb and between the two layers of the valves.

After soaking, hold the comb under the cold tap, placing a finger over the
tap to make a fast stream of water and direct it onto each valve so that
water passes under the valves and through the valve slots. To do this, the
stream of water will need to be directed both from the outer surfaces of
the comb and through the mouthpiece holes.  Take care to have the tap
turned on fairly low and not to make too strong a stream of water as this
can knock the valves off altogether.  Then tap the excess water out of the
mouthpiece/comb assembly and leave it to dry before reassembling.

If an inside valve is damaged or missing, you will need to dismantle the
mouthpiece/comb assembly to access it.  Remove the two mouthpiece screws to
separate the two comb halves, taking care to set aside the two brass nuts
that hold the mouthpiece screws. Then inspect the inside valves on the
upper comb half, comparing the valve for any problem reed with those on
either side.  If you need to remove a damaged valve, it would be best to
replace it with a new one rather than trying to reuse it.  Your Hohner
Service Department should have replacement valves available.  Clean off any
old glue from the comb before gluing on a new valve so that it will lie
flat on the comb.

Reassembly Instructions:

A paste similar to ChapStick-type lip balm is used at the factory to insure
a good seal between the mouthpiece and comb.  Before reassembling, apply a
thin coat of lip balm to the underside of the mouthpiece and the comb
surfaces facing it.  Replace the two brass nuts and reassemble the
mouthpiece and comb halves, making sure all three parts are properly
aligned.  Then replace the reed plates and all the screws, leaving the reed
plate screws untightened and only down enough so that the reed plates are
correctly positioned onto the comb.  Then, while holding the reed
plate/comb assembly in one hand with the heel of your palm at the back of
the comb and your fingers on the middle of the mouthpiece (around holes 5
and 6), press the mouthpiece tightly against the comb.  While holding the
mouthpiece tight against the comb, tighten the two plate screws at either
end of the front side and the two screws in the middle of the front side.
 In this way, the reed plates will hold the mouthpiece tight against the
comb, preventing air leakage.  Finally, tighten the remaining plate screws,
alternating between the back and the front screws.  The plate screws should
be tight but not over-tight.

Best regards,
Rick



> ----------------------------------------------------------------------
>
> Message: 1
> Date: Thu, 14 Jun 2012 16:31:30 -0700
> From: Robert Hale <robert@xxxxxxxxxxxxxx>
> Subject: [Harp-L] XB-40 bending
> To: harp-L list <harp-l@xxxxxxxxxx>
> Message-ID:
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> I have an XB-40 in A.
> What reed adjustments can I consider for making Blow 3 and 4 a little more
> responsive?
> Everything else is sweet.
>
> Thanks.
>
> Robert Hale
>
>