treble Coupler Modification.

[boxplayer4000]

Coupler Modification.
The owner of this LMMM accordion has asked if he can have a single middle M reed playing (and have the couplers altered accordingly).
Well, of course he can, with the proviso that one of the couplers will need to be selected to ‘play’ the single M middle reed (and the function/voices that the coupler originally served will no longer be available.)
I must admit I’m most at ease with modifications which can be fairly easily reversed, if for any reason an owner has a change of mind. This is a case where it is much less easy to reverse the modification because it will entail the removal of metal from at least one of the longwise, alloyed sliders, under the couplers, in the position of ‘Y’ red arrows.
I look at the levers marked ‘X’, four in total, and see how close they are to the grill cover and find myself thinking how easy it would be to access only one of them from the outside to let the player get his single reed selected.
I’m sure there’s plenty opinions out there how the ‘problem’ might be approached and look forward to reading some.

 

[tcabot]

Paul Debra has presented a solution for this de-coupling on an Italian-built Morino PA.

I've done it on my Italian Morino Club with great success and it's 100% reversible if you don't cut away the grille cloth completely.
One M becomes completely independent from the register machine. You've got a couple MM switches, so if one of the Ms is decoupled, that will give the option to play single M (Choose MM, and manually close the de-coupled M).
Your grille does not have a horizontal slot, so you'd want to make up a vertically-travelling switch instead.

 

[oldbayan]

Paul Debra has presented a solution for this de-coupling on an Italian-built Morino PA.

I've done it on my Italian Morino Club with great success and it's 100% reversible if you don't cut away the grille cloth completely.
One M becomes completely independent from the register machine. You've got a couple MM switches, so if one of the Ms is decoupled, that will give the option to play single M (Choose MM, and manually close the de-coupled M).
Your grille does not have a horizontal slot, so you'd want to make up a vertically-travelling switch instead.

I had an old LMMH Weltmeister on which all coupler switches had been disconnected and 4 sliders like that installed to give complete freedom.

 

[debra]

I had an old LMMH Weltmeister on which all coupler switches had been disconnected and 4 sliders like that installed to give complete freedom.

That's like going back to the old Excelsiors (and maybe others) with four rocker switches. Complete freedom, but not suitable for fast register changes.

 

[Siegmund]

I've always thought the ideal would be the 4 rocker switches, plus a few programmable presets.
It's not like the technology is new -- organs have had mechanical presets 'forever'.

OP: there's one other thing you might consider re modifying the mechanism.
Ordinarily you modify *both* sides of a switch, so that it has a tab on one end or the other of all 4 plates, i.e., create a"M" switch that opens M and closes L, M-, and M+.

What you might do is cut one tab off of another switch so that it just leaves one slider unchanged.

If, for example, you modify the MM+ switch from "open M, open M+, close L, close M-" to "open M, do nothing to M+, close L, close M-," you'd have a situation where if you move from master or musette to this switch, you get MM+, but if you move from M-M or LM or LM-M or L, you get just M. (Not saying MM+ is necessarily the one you should modify - takes some thought which one you want to change.)

 

[boxplayer4000]

Thanks to all for responding.
I remain hesitant about modifying the appearance of the accordion to the extent of a knob poking through the grille. (Volume and tone controls are just tolerable when they’re well located). I haven’t asked the owner about the change in appearance.
The picture below is of one of my accordions, a Fratelli Crosio, which I used a lot at one stage. As you can see the coupler range has three couplers all serving one purpose (the master) and I took a notion to convert one of those to just M+ and M- playing. This I did by modifying the long selector slides under the couplers.