I have recently obtained and put into working order a 5-octave Dulcitone. Here are some details.
Please click on any picture to get the full-sized version.
|The instrument is a 5-octave keyboard, tuned to A=440 but pitched one octave higher than standard piano pitch, operating by piano-style hammers hitting tuned forks (actually U-shaped bars). The case is of oak, with a base forming a soundboard of pine. There is a sustaining pedal, fixed to a stand that folds underneath for easy transport. Dulcitones were made by Thomas Machell & Sons in Glasgow, over period including the turn of the 20th century. It is thought that about 2000 were made, though this one has a serial number of 4362. Its date is unknown (but see below).|
|The lid is easily detached and the keyboard section can be lifted out by loops of cord and set down on a flat surface. The pictures show the front and back of the keys. Some of the key-springs were overstretched and I had to make some replacements. Below the front, the hammer springs can be seen, which are standard items that can be easily obtained, but would be difficult to replace as they are sealed in (the solution is to stretch them, with care: most needed it).|
|To make replacement key springs I used some brass harpsichord
wire of the right diameter, which I wound onto a rod mandrill using an electric drill slowed by a
variable transformer. Harpsichord brass is probably not the original
material, but it works fine.
The right-hand picture is of the principal part of the action, namely a key and a hammer. The hammer spring (fixed to the keyboard framework and not shown) presses down on the right-hand end of the hammer. Both the hammer spring and the key spring (visible) are necessary for the action to work satisfactorily. There are two screw adjusters included in the action.
|A larger view of the back of the keyboard section shows the hammers, not all rising completely to their official rest position, but good enough for the instrument to work properly (a little bit more stretching of the front springs could be undertaken, if it proved necessary). Within the action there were a few pieces of felt that needed replacing, and a local piano shop kindly gave me the right material.|
|Here's the interior. You can see, working from the top of
the picture downwards:
- the dampers, with the capped wires that are pressed down directly by the keys; for reasons I cannot fathom, the whole damper set was fitted too low, and I had to raise it and shorten the wires accordingly;
- at the top left there's a pull cord operated by the sustaining pedal to raise the dampers;
- the complete set of forks, with the small treble ones on the left of the picture; there are a few fine-tuning slips visible on the right (see text below);
- the transit rack, namely the wooden batten with nails in it; this is swivelled over by the cord on the lower left when the stand is folded up, and stops the larger forks from jiggling about sideways (a simple modification to disconnect/reconnect the transit rack cord proved easy to fit - so this instrument can be played on a table with the legs folded up, but then lacks the sustaining pedal);
- also a bar over the U-end of the heavier forks, presumably to stop them from jiggling upwards in transit.
|This instrument has a damper arrangement involving flat
springs, connecting the dampers to a batten by being nailed on at each
end. Some of these were loose, but could be tightened by taking them off
and judiciously applying glue to the nail holes (in later models a better
mechanism was devised). Incidentally I found that
some of the dampers had at some time been replaced, because of
discrepancies in the numbers stamped on them.
The right-hand picture shows a dismounted fork. Each fork rests on felt at the U-bed, is held fore-and-after by a short leather piece, and has a U-shaped piece of spring steel rivetted to it, which screws to a bridge on the soundboard.
|The maker's name (Thomas Machell) is on the front of the
open lid. He has also signed the soundboard, where, alas, the ink has run.
There is a splodge below it that might well be a date, but which is now unreadable. I have stared at
this till the cows come home, and tried photographically enhancing
it, and almost convinced myself that it might be 1884 or 1894, either of
which would be plausible. Or, for that matter, the splodge may have been
"& Sons", or "Glasgow", or something.
Other owners have reported that the writing on theirs is readable and that it includes "Glasgow".
|When everything was working, I checked the
tuning. All the lower-pitch forks had on them a piece of perished
near the U-bend, which was supposed to act as a fine-tuning device. They can
be seen in this picture, taken early on. Some of
these rubbed against adjacent notes and caused damping, so I removed them
all, and obtained some fresh rubber tubing (bunsen burner tubing is the
right stuff). Most notes were in tune to a few cents, but all the C's were flat by 20 cents, and one other note
was miles sharp. Solution: remove the offending forks, file the ends to
sharpen them, or near the U-bend to flatten them. In principle the forks
can be tuned slightly sharp, and fine-flattened by adjusting the position
of the rubber tubing slips: but I found that they make virtually no
difference, and I've fitted a few only. Hint on tuning: the pitch of a
fork when mounted on the soundboard is not quite the same as that when
clamped to a solid surface; take account of this when filing.
A few repaired cracks from earlier times can be seen in the soundboard; otherwise the soundboard is in good condition.
Full action diagram. This shows the damper mechanism to be different to, and presumably older than, the rather better design that can be found on https://en.wikipedia.org/wiki/Dulcitone .
|Final comments. The intention of the makers, it is believed,
was that the
Dulcitone would be a "missionary piano", being easy to
transport, and staying in tune. In my opinion it is not nearly robust enough to be carted around a continent on a donkey-cart.
It is said that the Nutcracker Suite was originally intended to feature a Dulcitone, but that the instrument proved too quiet, compared with a Celesta. One presumes that it is seldom used in earnest, and probably has mainly found its way into lofts and junk-rooms. Mine, indeed, had clearly been stored carelessly with something on top of it, causing a deep scratch in the top of the case - now resurfaced passably well using beeswax and French polish.
The picture gives the back view, with the Dulcitone name pierced into the oak (I replaced the decayed muslin cloth behind it: best to keep the flies out!).