CX12 Power Combs and Sliders

First released in 1992, the Hohner CX12 chromatic harmonica won numerous engineering design awards in Germany and quickly became the “workingman’s” chromatic harmonica. The innovative quick release torsion spring and tool-less slider assembly became an important and useful feature for harmonica players requiring quick maintenance access. The charcoal black “Darth Vader” model, available in numerous keys (plus Tenor C), and shown here--the Gold version, with chrome plated reed plates (only available in C):

There are two significant shortcomings with the stock Hohner CX12 harmonica: (1) loose tolerances between the slider and injection molded slider railings (channel) and (2) poor mating surfaces between the face of the comb and slider. These issues show up for the player as lack of responsiveness/sticking slider and breathy notes.

Fans of the Hohner CX12 can rejoice, because our friend--internationally known and certifiable harmonica “Nutty Professor”--Brendan Powers, has developed and offers a retrofit kit which eliminates the shortcomings of the CX12 harmonica. http://www.brendan-power.com/combs-hohner-CX12.php

Recently harmonica student Bjorn Nielson brought his gold CX12 harmonica and Powers CX12 comb and Power Slider to me:

The comb on the left is the Power comb, which Brendan manufactured on his 3D printer (notice the milky finish, hallmark of a part created with a 3D printer). On the right is the stock Hohner ABS comb.

Most notable in the Power combs, are the “on-ramps” and “off-ramps” Brendan designed into each slot. This design is significantly more efficient method of directing the precise amount of air flow to the chosen reed (remember, there are two reeds per slot), as compared to the stock comb,

where the flow of air can be a bit convoluted between the two reeds.

The precision (read: super flat!) stainless steel face is mated to the composite comb. Look closely and you will notice the air ramps install the channels.

Four (4) indexing slots, rather than the stock two slots are machined into the stainless steel face plate--making a perfect match into the CX12 shell.

Shown here is the new stainless steel slider.

Power slider is thicker at 0.89mm, closing the gap between the face of the comb and the inside of the slider. Less leakage means more control for the player and less wasted breath!

Stock Hohner CX12 slider is thinner at 0.82mm

Power slider measures 13.63mm width

Stock slider measures 13.59mm width

Precision made Power slider eliminates the typical CX12 slider “slop”.

I found the easiest way to remove the slider button from the original slider assembly was to hold the button in a soft jawed vise, then simply grab the slider with your hand, and pull away. Repurposing the original button onto the new Power slider is simply a push-into-the-slot procedure.

Reload your assembled reed plates/comb assembly back into the shell.

Slide and snap the torsion bar in place.

Install Power slider

Snap button/spring assembly into place.

TIP: With all the reeds exposed, use this opportunity to do tuning and replace faulty windsaver valves. You’ll thank me in the morning ;o)

Your Harpsmith, Kinya

http://www.brendan-power.com/combs-hohner-CX12.php