INTEGRATED SLIDER-MOUTHPIECE - Tech Tuesday #7

[Brendan]

My horizontally moving Slider-Mouthpiece invention has some useful advantages over conventional harmonica slider assemblies. Here I describe its back story and essential features:

https://youtu.be/iU-TrFzMbh8

[JoshuaDb]

I have a Seydel deluxe steel in PC tuning, half valved. I love it's sound - but I feel it could be more responsive. The slide assembly im not thrilled with. It's got a long travel on it, and gets off track easiky. An aftermarket mod like this would make such a difference.

[Brendan]

I know what you mean... That traditional multi-part slide assembly is prone to leakage. Try using slider oil on the slider, and Vaseline between the stationary parts, to improve the airtightness.

Besides the integrated mouthpiece/slider, I have designed a low profile two-piece 'self sealing' slide assembly for the Hohner 270/Seydel Deluxe type of chromatic, but never publicly released them. Maybe it's time to look into that.

[PeteHogi]

I'm interested in trying this out for the Game Changer Harmonica. I notice, if I play it with out the mouthpiece, I can feel the reeds more during bends and such.

The mouthpiece it comes with is already pretty shallow, which is good, but I'm curious just how close I can get to those reeds.

One question - it seems with this design on the Game Changer, that pushing the slide in would shift the hole 1 off to a spot where no reeds would play. If you wanted to play 1 blow and then 1 blow slide-in, you would actually need to shift to hole 2.

The alternative would be to design it with the slide pushing in from the left side. That'll be a big change in the way I hold the instrument! Another alternative would be retuning so that each chamber's reeds swap with the chamber below it. That is probably the answer via a lot of blue tak.

I'm curious what thoughts you all may have had concerning this. Ideally I'd like to engineer it so that the function is very similar to the current design, just with less distance to the reeds.

[Brendan]

In my opinion, JDR made a mistake with the tuning layout of the Trochilus.

Due to the comb design, the two blow/draw pairs in each mouth hole are adjacent to each other, separated by a comb divider opening to a slide hole.

Since the slider is pushed from the right and moves right to left, they should have had the default slide-out scale starting from the RIGHT of the two adjacent comb chambers (instead of the left, as in the production model). This would mean the slider only needs 10 holes, instead of 11 as at present.

It's more elegant and avoids that bodged 11th slider hole. Also would result in a stronger slider.

If you tune your Trochilus this way, you could make an integrated one piece mouth-slider in the most efficient manner.

But, although it's physically possible, I wouldn't use Blue Tack for such a comprehensive retune. When I first started using it in around 1980 it was always intended for reversible tuning of just the odd reed - not all the reeds in a harmonica! Too slow, and it looks ugly...

For a comprehensive retune, use a combination of solder to lower reeds and preferably a rubber polishing wheel to raise them. With practice you can retune a reed up to 3 semitones higher (and a lot more lower) in just a few seconds.

Good luck with your project! It will be interesting to see if you find much difference in performance from the stick Trochilus mouthpiece/slider, which is pretty gootin my opinion.

Although it's a worthwhile project to try, I suspect that you'll end up concluding that the gain in volume/response will be too small to justify the amount of work and time involved. But you won't know until you try

[triona]

In my opinion, JDR made a mistake with the tuning layout of the Trochilus.

Due to the comb design, the two blow/draw pairs in each mouth hole are adjacent to each other, separated by a comb divider opening to a slide hole.

Since the slider is pushed from the right and moves right to left, they should have had the default slide-out scale starting from the RIGHT of the two adjacent comb chambers (instead of the left, as in the production model). This would mean the slider only needs 10 holes, instead of 11 as at present.

It's more elegant and avoids that bodged 11th slider hole. Also would result in a stronger slider.

I am not that much into harmonica tuning layout design. But this is what I suspected from the beginning. You just boiled it down to its theoreticel grassroots.

I think the Trochilus is a nice try of a new and innovative Chinese harmonica manufacturer. But maybe they should have asked someone like you in advance.


dear greetings
triona

[PeteHogi]

I hadn’t considered that the tuning layout requires an extra slider hole, but that makes sense.

It might take some time but I’ll give it a try.

I’m also wondering if eliminating the extra slider hole could hole could reduce the length requirement for the front of the harp. I think an ideal version of this harp would be as close as possible to a traditional size harp.

The other angle, I’ll need to take one apart to see, is I notice that there’s some distance between the front edge of the reedplate and the reeds themselves.

I wonder if grinding that off, shifting the plates closer by about 1mm, would make any difference.

Thanks Brendon for your thoughts. I’m really excited to have a chrome that overblows well, but I sense that there’s opportunity to tweak!

[PeteHogi]

Thinking about this again,

The slider mouthpiece alone can be tried without tuning. I’d just have to reverse the way I use the slide! Mainly play with the slide pushed in, and let it out as needed. Or vice versa for playing in flat/sharp keys.

That’d get to proof of concept faster, so that’s the route to try, I think.

[Brendan]

Good thinking on the way to test quickly.

TBH I think you're putting too much weight on reducing the number of millimetres between mouth and reeds. Compared to a normal chromatic (especially the modern Suzuki or CX-12 inspired ones), it's already quite a bit less distance on the Trochilus.

As long as the slider is really airtight, moving your mouth in or out a few mm won't make any noticeable difference. It's perfectly possible to overblow a CX-12 if the harp is airtight, and the reeds a considerably further from the mouth than in the Trochilus.

For overbends, I think put your attention to:

1. Making the slide as airtight as possible. Try slider oil or a very fine layer of a food safe grease, like Vaseline.

2. Drill holes and attach three front screws on the reedplates. I've done that with my half-valved sample, and it makes that setup work well. It should also help on an un-valved standard setup. I used M1.2 screws, but M1.4 would be ok too. Just make sure not to drill through the reeds, and keep the head of the screw back far enough to allow the top cover to sit down on the reedplate.

3. Emboss the reed slots. This is standard procedure for any overblow harp, and the Trochilus is no different.

I suggest try those things first: they will make quite a noticeable difference!

[Brendan]

Triona: thanks for your kind comments.

Since I know the JDR people from meeting them at trade fairs in the past, I've passed on the tuning/slider suggestion, plus a few other ideas for improving the Trochilus. It's already good, but can still be better