Fascinating! Was the "two buttons to one chamber" accomplished by each button being connected by its own lever to its own pad (the pad pan having two holes adjacent to each other both above this chamber, each covered by a separate pad) or by some mechanical linkage where there was a single pad which could be lifted by either of the two buttons?
If the former, is there ever an intonation difference (as the two pad positions would result in different airflow through the chamber)? I know the ideal pad location is over the rivet end of a reed, not the tip end, and (at least with accordion reeds, not sure about with concertina reeds) this can make an enormous difference in the sound quality.
(Of course, with a 45-key, there are also some reeds under the action board as opposed to around the perimeter of the instrument -- possibly including the chamber in question -- which, as I recall from a previous discussion between Robin Harrison and Adrian Brown and others, results in tonal differences ... which might be be greater than any difference caused by pad location over a chamber?)
If the latter (a mechanical linkage of some sort), I would love to see photographs of the lever arms of such an instrument as well as hear whether both buttons feel similar to each other and the other buttons on the instrument -- in terms of pressure needed to move the pad, resistance from springs, motion lost due to mechanical transfer, and the like.
(On my customized 32-key Morse C/G, my left thumb has F#4/C4 and I've given up the duplicate G4/A4 reeds on the "G row" in favor of a F4/E4 reeds for that button -- all four of those notes are extremely useful in my playing style! I've also -- on the right side -- got an F#5 on the press in the exact same location as on this 45-key, and an F5 in nearly the same "pinky finger" location. ... At some point I'll just start a thread on locations of various "alternate notes" on different anglos of different numbers of buttons, and various custom layouts folks have developed, but before I start that thread I want to organize the data I've collected thusfar a bit more. As you might guess, this is a particular interest of mine, both theoretically as a player and practically as a concertina builder for R.Morse&Co.)
I'm actually more than mildly interested in this instrument, but given the (totally reasonable given the instrument, to be sure!) price it is of course a consideration not to be taken lightly (also, as sound and feel can vary widely among Jeffries, it's hard to really know how I'd like the instrument without handling and playing it, no easy feat for me, living in America). One further question: I've seen another Jeffries 45-key anglo where the buttons are of very small diameter (perhaps 3mm?); here in these photographs, they appear to be a bit larger (more like those I've seen on some 31-key Jeffries (perhaps 6mm?). Could you give their actual measurement? Thank you!
Edited by wayman, 16 August 2013 - 08:14 AM.