Copying Existing Organ Stops

[bombarde32]

I am also given to understand that the type and construction of the soundboard and its associated mechanisms has a profound effect upon the resulting 'copy'. A good example of this would be comparing a Compton action to a Wurlitzer...............

[Pierre Lauwers]

I am also given to understand that the type and construction of the soundboard and its associated mechanisms has a profound effect upon the resulting 'copy'. A good example of this would be comparing a Compton action to a Wurlitzer...............

 

Also interesting are:

 

-The older neo-baroque organ built on Taschenladen (pneumatic chests with one membrane per pipe)

 

-Walcker Pipework placed on new slider chests.

 

Pierre

[pcnd5584]

What a fascinating thread, and a fine demonstration of the diverse knowledge and talents we have on this Forum.

 

Indeed - I even understood it - which is a great rarity; i.e., a person of scientific bent who is able to impart specialised knowledge to the uninitiated without 'dumbing-down' the information. Thank you.

[Lausanne]

I am also given to understand that the type and construction of the soundboard and its associated mechanisms has a profound effect upon the resulting 'copy'. A good example of this would be comparing a Compton action to a Wurlitzer...............

Yes, in attempting to make a copy of an organ pipe, the builder would have to consider the soundboard construction, or at the very least, whether the pipes were winded from a groove (slider and pallet) or an individual valve. There are many varieties of the latter, but most tend to make the pipe speak more abruptly than the traditional slider and pallet.

 

The actions used by Compton (several types) and Wurlitzer are not really all that different and mainly in the 'abrupt' wind category. Some pipes, like the Bourdon, don't like abrupt wind and often builders using these sort of actions have had to add extra chambers or grooves between the valve and the pipe. The difference between the action types is particularly noticed with low wind pressure. As Pierre mentioned, on the continent during the last century many organs have been built with taschenladen membrane valves, but on the same pressures (around 75mm - 95mm) as the slider and pallet. I have seen several taschenladen rebuilds using pipes originally voiced on the slider and pallet action, and it seemed that only the wood pipes had required changes to their upper lip, probably to prevent them sounding the octave. Of course, some pipes prefer the abrupt winding, reeds particularly like a good old kick up the boot (? - well, you know what I mean) and it is for this reason that they are usually positioned directly above the pallet in a slider and pallet soundboard. With the ultra low pressures typical in early Spanish organs (50mm), this was essential, but with the pallets usually being at the front of the organ, this meant that tuning the reeds was only possible if they stuck through the case and so Chamades were born. Well that's one theory anyway.