So you want a French sound?

[Dingo40]

John,
The marks are on the exterior, on a dedicated plaque attached to the treble box at the upper front.

It is an unusual instrument insofar as it is nominally an LMMH instrument presumably the two M's are tuned A440, 442 (or 440, 438). , then a separate "on" and another separate "off" lever ( two in all) actuate or deactuate (seemingly) a third M reed, which remains in force across all couplers (affecting all the reed combinations, when "on", giving to all combinations a wetter sound ). This gives a very nice "musete" effect in the violin or "MM" coupling ( becoming seemingly MMM), although the nominal or "official" musete coupling (which, with the musete lever "off" is MMH) then , seemingly, becomes MMMH and wetter. :huh:

I have searched the net for information, but without any success, although there was one advertised for sale. 

 

[maugein96]

John,
The marks are on the exterior, on a dedicated plaque attached to the treble box at the upper front.

It is an unusual instrument insofar as it is nominally an LMMH instrument presumably the two M's are tuned A440, 442 (or 440, 438). , then a separate "on" and another separate "off" lever ( two in all) actuate or deactuate (seemingly) a third M reed, which remains in force across all couplers (affecting all the reed combinations, when "on", giving to all combinations a wetter sound ). This gives a very nice "musete" effect in the violin or "MM" coupling ( becoming seemingly MMM), although the nominal or "official" musete coupling (which, with the musete lever "off" is MMH) then , seemingly, becomes LMMMH. :huh:

I have searched the net for information, but without any success, although there was one for sale. 

Dingo,

I seem to remember Paul De Bra explaining how an accordion like yours works. I have no technical knowledge whatsoever with regard to accordion mechanics, but the feature appears to have been used on other Bugari models with double cassotto. 

Found this demo where the white lever on the grille is described as a mute. Does it ring any bells with you? There are also two "register" switches which I believe the player says "brightens" up the musette? 

Any chance your accordion was originally an LMMM, but had the low M removed and replaced with H reeds? It is a bit of a puzzle right enough.

Or is it in fact maybe a LMMMH like the one in the clip?

 

[debra]

John,
The marks are on the exterior, on a dedicated plaque attached to the treble box at the upper front.

It is an unusual instrument insofar as it is nominally an LMMH instrument presumably the two M's are tuned A440, 442 (or 440, 438). , then a separate "on" and another separate "off" lever ( two in all) actuate or deactuate (seemingly) a third M reed, which remains in force across all couplers (affecting all the reed combinations, when "on", giving to all combinations a wetter sound ). This gives a very nice "musete" effect in the violin or "MM" coupling ( becoming seemingly MMM), although the nominal or "official" musete coupling (which, with the musete lever "off" is MMH) then , seemingly, becomes LMMMH. :huh:

I have searched the net for information, but without any success, although there was one for sale. 

These couplers suggest that the accordion is a 5 voice instrument, LMMMH in which the -M reed can be switched on or off independent of other reeds. (This gives more register possibilities than a standard set of 15 registers could accommodate.) Such an on/off switch is also used on accordions that have a "fifth" (so with C a high G would play simultaneously, something you would rarely use, but church organs often also offer this). Having MMM tuned 438, 440, 442 is a logical choice as every Hertz is about 4 cents so this means the reeds (for central A) are tuned to -8, 0 and +8 cents. The 0 and +8 combination is good as a "french musette" which has low tremolo, while the MMM -8/0/+8 is a nice "civilized" musette for some other music (but is too civilized for Schottish or Irish music).

 

[Dingo40]

Thanks, Paul,
That does seem to describe it

( BTW, I see I have made an error. It should have read:

"When the "musete on" lever is actuated, the musete coupling (which is nominally MMH, with the "musete off") appears to become MMMH and sounds wetter, as indeed do all the couplings)