Brendan Power & Alternative Harmonicas Forum

With the generally favourable reviews of the JDR Trochilus/Bushman GameChanger harps and the new Knittlinger which uses the same platform I had overlooked the possibility of making a right proper 40 reed all bending harp.

I like the Game Changers; both the Blues Shifter and the Pop configurations. I would keep the Pop version much as it is A lot more Jazzy possibilities. Before making the Knittlinger octave harp however I don't know why JDR didn't first use use the success of the Trochilus to make an all bending Blues harp. Keep the innovation they've achieved but removed as many items that might prevent the stubborn long time player from giving one a try.

1) Remove the slide.
2) Remove every other chamber divider such that every hole has four reeds. Valve the primary reeds. Set the gaps on the X reeds to zero.
3) The Trochilus plates should work and just need a different but simple note layout scheme.

I think this arrangement would do much better than Suzuki's ill fated SUB30. A bit bigger than standard 10-hole but still very playable. You give up some natural unbent notes but now all 10 holes can be bent on both blow and draw.

@ Roverharp: it sounds good in theory, but in practice it's not quite so simple. That setup will work, after a fashion, but won't sound good on chords - unpleasant overtones will kick in. Relying on zero reed gapping for the x-reeds is not enough.

If you look at the design of the Hohner XB-40, you'll see that when you blow or draw, all your air goes only to the active reed and its corresponding X-Reed. Same with the AsiaBend: the slider isolates just the two reeds required for the note and bend.

In the setup you describe, air is also passing through the opposite x-reed slot. Even with zero gap, some dissonance can occur - especially on chords. And because of the extra reed slot in the airflow (3 reeds instead of 2), the harp sounds more airy.

When Zombor Kovacs and I released our custom Suzuki SUB30, we added an OverValve Plate to fully cut out the x-reed on the draw breath. This is a plate that sat about 1mm high on top of the upper reedplate with valves over the x-reeds. The valves closed on the draw breath, cutting the x-reed out of the airflow. This gave a purer sound on the draw notes and allowed normal blues harp chords to be played.

In your concept, with a second x-reed on the inside of the draw plate, the harp should have an OverValve Plate on the inside as well, between the comb and the lower reedplate. I've made some designs like this, but it's very cramped in there and you now have extra parts and 4 valves per hole... Complicated and noisy.

That's the beauty of Rick Epping's XB-40 design. It achieves the twin reed isolation required for good sound and performance in a full x-reed harp with only two valves per chamber. That's because the valves are in the comb, activated before your air gets to the reeds. Besides being effective and efficient, this front valve system also means the reedplates can be clean, with no valves attached at all - nice!

I discovered this front-valve concept was also thought of by Richard Sleigh for a twin diatonic x-reed harp back in the 1980s. He was using small circular valves in a mouthpiece attached to the two combs. He told me he never managed to make it successfully because the valves were so small and fiddly.

I thought of a similar approach independently a lot later, and made a few prototypes that worked. I called mine the UniBender. You can hear one at the end of this video at about 8:40:

https://youtu.be/xK_wXODAQ0Y?is=dOB5aIYv2M696KmZ

Unfortunately with harmonicas, things are never as simple as they first seem... But I encourage you to go ahead and make your design anyway from a Knittlinger - you might come up with a whole new way to overcome the problems.

Ah yes. I should have known my cursory glance was too good to be true and especially because if it was viable you would have already introduced such a beast