QUIETING DOWN THE SLIDE ON A HOHNER CX-12 JAZZ chromatic harmonica…

QUIETING DOWN THE SLIDE ON A HOHNER CX-12 JAZZ chromatic harmonica…

You will find this unique customization pretty much solves that problem.

The Hohner CX 12 Jazz is a very different design, having an integral gold/orange plastic combined cover/mouthpiece…and NO mouthpiece screws and no bumpers.

The comb/reed assembly simply plops into the back of the cover, and a tension bar spanning the back of the unit holds all taught.

Cool, easy to assemble and disassemble, great projection of the covers so open at their back.

The uniquely designed SLIDE slips and then clips into the right side of the unit, with just enough room between the inner surface of the mouthpiece and the comb for the slide to fit, and “snap into place.”

Cool design but a bit noisy.

Noise explained…

There are two sources of NOISE from the Hohner CX 12 Jazz when the slide button is pushed in…which can be minor or severe depending on the push you give the slide…(you essentially get a CLICKING SOUND of two pieces of plastic hitting each other.)

1) The larger source of the noise (70%) is the fact that there is a white post on the inside of the slide button, of approximately 3/16″ diameter, around which a spring is placed (which provides rebound of the slide after it’s activated.)

When the slide is in place, the white post stops the movement of the slide when it has reached its maximum “pushed in” position…by hitting a part integral to the right side of the comb, which I’ll call the “X bang post.”

The X bang post is a very small black plastic extension of the comb (located on the right side of the black ABS comb, just a little peg really, which is 3/16″ in diameter and about a quarter of an inch below the top surface of the comb) positioned so that the white post of the slide HITS it when the slide is fully depressed, providing an end to slide movement when the slide is depressed. The X bang post has has a small + (plus sign, or X) cast on its end.

Again, when you push the SLIDE in all the way, quickly, you will hear a CLICK sound as the white post of the SLIDE hits the X bang post of the comb .

The photos show what i’m talking about.

The repair is straightforward.

What you want to do is to provide a very thin protective layer of synthetic cork, no thicker than 1.5 index card thickness…between the WHITE POST of the slide button and the X BANG POST on the comb…but note their interface (where they hit each other) is small…a circle of about 3/8ths of an inch.

The easy way to do this is to go to an instrument repair shop and ask for a postage stamp-sized piece of very thin synthetic cork. (See photo)

Using cuticle scissors or other means, cut a very small dot of cork, then glue it to the end of the X bang post with glue. I used super glue, because it’s very thin, some recommend leather glue.
(See photo.)

Be careful when cutting the piece of sheet cork, because it must be small enough diameter for the end of the SPRING on the slide button to easily clear it, allowing the slide’s spring to get over the X peg and seat properly on the X bang post. (One end of the spring is attached to the slide over the white post, and the other end of the spring seats over the X bang post.)

When the cork is in place, the slide’s white post will hit the cork, not the raw plastic of the X bang post of the comb.

This very thin material will absorb the whack, and quiet down the slide…pretty much eliminating the noise.

(Be careful that you do not use too thick a material for the cork, or you may change the tolerance of the hole/slide lineup. Go for very thin, and use a synthetic cork, or real cork/synthetic mix which is VERY THIN. About the thickness of 1.5 index cards…very thin.)

Apart from the peculiarities of working with and cutting a circle out of a very small piece of sheet synthetic cork, you should have no problems.

2) The second source of noise is caused by the lack of a tight fit between the SIDES OF THE SLIDE and the molded mouthpiece/cover.

The fix is very simple…just use your fingertips to put a tiny amount of slide oil (I use Hetman’s Synthetic Light Bearing and Linkage Lubricant 13…often used to lubricate saxophone keys) on the slides sides and sides.

Just a little, no dripping, just a very thin, light coat.

This will quiet things down a bit.

Good luck!
(Photos are: 1) A Hohner CX 12 Jazz…2) The cork in place on the X bang post…3) Sheet cork….4) White post of the slide button

1) A Hohner CX 12 Jazz Chromatic Harmonica

2) The cork in place on the X bang post:

3) Sheet cork:

4) White post on the slide button: