Bass Reeds Modification

[Sebastian Bravo]

Hi to everyone.

Months ago i started to learn Libertango by Astor Piazzolla. And now i can play it very well.

The chords in some part goes Am-G-F#-F-E (Not sure if some are seventh or diminished chords but anyways, the bass notes are the thing here) and it sounds bad in my accordion, because my lowest note is G. The transition to F# sounds weird because it is one octave higher than expected.

So, i decided to modify some reeds to get that low E bass, as i got another bass reed block from a Hohner Tango VM

I did some work on the low E reed (It was E2 checked by Datuner App) and the reed was flat metal (With no weigh on the top) so i put some Solder on it, and was a success. Then i did the same on the next higher E, that was E3, and i put solder on the top and got it down to E2.

<ATTACHMENT filename=IMG_20180223_045936_057.jpg index=0>
(It was on my instagram story)

First test, the reeds sound like this:


I tapped the chord reeds to hear just the new modified bass (They arent perfectly tuned but they seem to work) The low E1 delays 1 second (which i think is normal, but im trying to lower that delay)

The problem now is that the E3 note is missing. And it cant be on the chord section because the chords will sound different than usual with that E3 note playing.

So, i will need to make a new reed block. I was thinking in a winkelbass construction to fit 3 reeds to E3, F3 and F#3

What do you think, is it crazy enough? i know that buying a new accordion would be easier, but i really like this model and i want to modify it to give it more functions (I will also modify it to be a 96 bass, as i got the buttons from another hohner bass machine, with 12 buttons with free bass function, 6 of these are functional now: I need to drill the new holes)

Any suggestions and support will be helpful!

 

[debra]

Once you start changing one bass note (by one octave) you are basically moving the octave jump problem to a different location and now you run into the missing E3...
But then... the bass notes on this instrument are essentially what they are because of size limitations. To get a "good" sounding lower bass you need larger reeds. They will still require a weight for the lowest notes but less so than when you start out with shorter reeds in the first place. Also, the reed you weighed down may not have the strength to withstand the extra stress for very long so it may break in the end...

 

[Sebastian Bravo]

Once you start changing one bass note (by one octave) you are basically moving the octave jump problem to a different location and now you run into the missing E3...
But then... the bass notes on this instrument are essentially what they are because of size limitations. To get a good sounding lower bass you need larger reeds. They will still require a weight for the lowest notes but less so than when you start out with shorter reeds in the first place. Also, the reed you weighed down may not have the strength to withstand the extra stress for very long so it may break in the end...

How long is the low E reed on your AKKO?

 

[debra]

...
How long is the low E reed on your AKKO?

Next time I open it up I should measure that... In any case these reeds are pretty big, fixed with two rivets, and the added weight is quite small (or thin) compared to what I have seen on even the largest German or Italian boxes (including the Hohner Gola). The largest valves you can order from Italy are 92.5mm if Im not mistaken. That says something about the size of the largest Italian reeds. The Russian reeds may be a bit longer, but not by a whole lot.

 

[Morne]

Sebastian, for what its worth, here are the dimensions of E1 in my Morinos. They are simple ruler measurements, so they might be sligthly off.


Definitely keep us updated on your free bass modification. Before I got mine, I also thought about one day modifying a non-free bass to achieve that. Now I dont have to, but Id still be interested in seeing how far you get.


Edit: I originally showed that the VI M reed had a taper. This is not true. It is uniformly 6mm as well.

 

[Geronimo]

Sebastian, for what its worth, here are the dimensions of E1 in my Morinos.

Nicely and comprehensively done, could be straight out of a reed catalogue.

 

[debra]

...
I tapped the chord reeds to hear just the new modified bass (They arent perfectly tuned but they seem to work) The low E1 delays 1 second (which i think is normal, but im trying to lower that delay)
...

A 1 second delay is certainly not normal for a good E1 reed, but for the home-made one it may be acceptable.
When I first received my Pigini bass accordion the lowest reeds had about a one second delay. I could adjust the voicing of the reeds to lower that, and on my AKKO its almost instantaneous. The more a reed needs to be weighed down the harder it is to make it respond quickly.

 

[kimric]

I this case it may be worth looking at bass reeds from different instruments. They are not standard by any means. A longer reed will have a lower pitch with the same weigh on the tip.
I reworked a Chinese bass accordion I got at a trade show. I replaced a lot of the lower reeds with Italian ones from different parted out instruments to get the fastest response. The really low reeds in the chinese instrument were hard to duplicate and bigger than anything I had so I reworked those to get better performance and paired them up with the best octave reed I had to boost the response time.
It was a compromise but it turned out pretty well.

 

[Sebastian Bravo]

Sebastian, for what its worth, here are the dimensions of E1 in my Morinos.

Thanks Morne! It is really helpful to compare them with my Tango VM reeds. They seem to be really similar, but the bass reed itself is shorter (53mm) than the Morino reeds (60mm). Also, Tango reeds are double riveted, and the morino reed is just single rivet, but it works to make more space to the reed (that extra 7mm) and because of that, the reeds are obviously bassier and can achieve the E1.




So... Modifying the reeds can be possible but the delay is the problem, because, as Paul De Bra said, if the reed needs a lot of weigh on the top to get to E1, it will be harder to make it respond quick. And i think i got this idea:

-Remove the rivets and the reed
-Sand down the space of the first rivet, to put a longer reed
-Make the new longer reed from scratch, as the Mexican guy Angel Pequeño teaches on his video (Ive made 10 or more small reeds with his tutorial )
-Add weight to the top of the reed and tune it down to E1

Buying new reeds will be expensive because of the shipping from Italy. I live in Chile, South America. So, i will use 100% homemade reeds for this test

I will post new information when i finish one reed. Wish me success!

Definitely keep us updated on your free bass modification. Before I got mine, I also thought about one day modifying a non-free bass to achieve that. Now I dont have to, but Id still be interested in seeing how far you get.

The plan for that modification is just 12 free bass notes, to play simple melodies when i play accordion (left hand) and glockenspiel (right hand), and to make my own chords to play tango and some pachebel songs. This hohner stradella system dont allow you to open just one reed, it have 2 pallets per note, one for the two bass reeds, and the other for the three chord reeds. So, the notes goes from G to F#.




I had to remove the small gold pins of the buttons, that were chords, and asign a new note to each button. I used wires and solder to make the new pins, and thats all. The video i posted shows how they work. So, when i drill the holes to get 96 bass, i will asign the other 6 possible notes (G to C). The notes also work with the available registers, so i have single notes, and LMH notes (LMH sounds really good!)

Ive always asked myself, why did hohner made the Concerto III with 72 basses... Concerto I is a 48 bass, concerto II is a 72 bass, Concerto III is also a 72, and Concerto IV is 120 bass! why not a 96 bass model? I have a friend who owns a Hohner Tango IIM, It is 96 bass in the same body size of the Concerto III, it even has 3 bass registers!


That motivated me to modify it!

I reworked a Chinese bass accordion I got at a trade show. I replaced a lot of the lower reeds with Italian ones from different parted out instruments to get the fastest response. The really low reeds in the chinese instrument were hard to duplicate and bigger than anything I had so I reworked those to get better performance and paired them up with the best octave reed I had to boost the response time.
It was a compromise but it turned out pretty well.

I remember reading that in the forum on another topic months ago!

 

[Morne]

They seem to be really similar, but the bass reed itself is shorter (53mm) than the Morino reeds (60mm). Also, Tango reeds are double riveted, and the morino reed is just single rivet, but it works to make more space to the reed (that extra 7mm) and because of that, the reeds are obviously bassier and can achieve the E1.

The reed on the left in my picture is E1 from a 1953 Morino. The reed on the right is E1 from a 1959 Morino. Your reed looks a lot like the one in the older Morino (narrower plate, double rivet, shorter tongue).

So... Modifying the reeds can be possible but the delay is the problem, because, as Paul De Bra said, if the reed needs a lot of weigh on the top to get to E1, it will be harder to make it respond quick.

I think one thing to also keep in mind is how the air flow is affected by the reed chamber size of these low reeds. Both my Morinos have non-standard reed blocks. The older one has this:



The later Morino has a tall block:


As far as I know, the Morino Ms, which are roughly contemporaneous with that Tango VM, always had some kind of bigger low bass reed block.
See also Geronimos photos here: https://www.accordionists.co.uk/viewtopic.php?f=3&t=5461&p=54949#p54952

Now, I might be totally wrong, but perhaps youre not going to get a homemade E1 to respond quickly without a corresponding reed chamber/air flow change. At least not with those Hohner reeds from that era.

Buying new reeds will be expensive because of the shipping from Italy. I live in Chile, South America. So, i will use 100% homemade reeds for this test

I will post new information when i finish one reed. Wish me success!

Best of luck and keep us updated!

The plan for that modification is just 12 free bass notes, to play simple melodies when i play accordion (left hand) and glockenspiel (right hand), and to make my own chords to play tango and some pachebel songs.

The other cool thing with free bass is that you can now also eat or have a drink while youre playing. :lol:

 

[debra]

I did the measurements like Morne did, which means the length of the vibrating part, from just past the rivet(s) to the tip.
I just measured: on my Bugari 540/ARS/C the longest reed (E1) measures 60mm, and on my AKKO Super "de luxe" the E1 reed measures 80mm. Also the weight is considerably thinner which may help partly explain the better response.

 

[Geronimo]

On my main instrument of Morino style, the bass reeds all have the same size, 60mm x 6mm active area. On the E1, the weight is 14mmx2mm (it's definitely longer on the E♭1 and D1: maybe those reeds are actually repurposed E1 reeds).

80mm with smaller weight should indeed give the AKKO a quite better pitch at more immediate response. I don't feel that I have reason to complain (certainly not a delay of 1s), but the reed response does factor into the playing technique and into accessible speed at various volumes.

 

[debra]

Just a quick shot with my phone...
The size of the E1 reed is really 80mm from past the rivets to the tip.