Unification, Borrowing and Duplexing

[jbird604]

ed. This thread was split from this one-Admin

Yep, recycling is the best use of these organs, although we do service several of them still in regular usage in settings where their glaring faults are not noticed. For example, there are small churches with amateur organists who desire nothing more than a basic 8/4 chorus with a substantial 16' pedal. The MDC models deliver that nicely. These are organists who don't experiment with different registrations, hardly know what a celeste is, and have no need for reeds or mixtures or a carillon or couplers. Hammond players, in other words.

We have gotten a few of these things in trade over the past year or two. We resold one to an organist for a practice instrument in her home. One we gutted and gave the console away. We have an MDC 52 -- nice AGO console -- for sale in our shop. Adding MIDI to it would make it a lot more interesting to someone who wouldn't mind learning to use an external MIDI device to get anything beyond the plain sounds on the stop rail.

Truth is, though, we have too many organs sitting unsold right now to fret over one MDC model. Someone may come along who will love it just the way it is. Folks who want a more complete organ will be more interested in one of our MOS or ADC organs.

[Hamman]

Yikes Jbird them are fightin words! LOL I'm a Hammond player but also appreciate the classical sound very much. Heck I'm wanting to get a 2 manual MDS as soon as I can find a decent one here on the left coast.

[jbird604]

No offense intended to Hammond players. I love them one and all! When I referred to them, I only meant that the shortcomings of these MDC models would not offend Hammond players because they also have no mixtures, couplers, celestes, real reeds, or carillon. I know, of course, that Hammond tone wheel organs can create a huge variety of sounds, including reeds and mixtures, and many players use that ability. Sadly, I know far too many church players who have their drawbars set on some dull muddy sound and never move them.

And no offense to those who play and enjoy an MDC organ. You can make a lot of nice music with a simple set of three tones unified at several pitches. It's a far cry from a big Allen digital with dozens of distinct tone colors and no unification or borrowing, but people tend to like what they are familiar with.

[Hamman]

Jbird...what do you (and others I have read) mean by unification?
Is that like taking a flute voice and manipulating into a reed or square wave or?

[Kurzweil]

Unification is the expanding of a rank (electronic OR pipe) to produce multiple stops. An 8' diapason, for instance, consists of 61 pipes with the lowest being 8' long, hence the name. Through unification, the builder can pick up this same set of pipes (generators) at the tenor C, the 4' pitch, and make a 4' diapason, maybe called principal or something different. He need only add twelve more tiny pipes at the high end to make it sound the full length of the 61 note manual. The rank is now 73 notes instead of 61 and produces two stops instead of one.

This can be carried out extensively until the rank is well over a hundred notes and sounding everywhere from 16' up to 1'. Theater organs are seldom built any other way. It becomes a characteristic of their sound; all those notes that DON'T get doubled, but it is somewhat frowned upon with classical organs. With those, one wants one set of generators per stop, ideally. The analogs rarely could do this - - far too expensive. A pipe organ would cost about the same, I've heard. With digitals, I believe that unification is rarely used anymore where classical organs are concerned.

The wave altering you mentioned was also done on almost all analogs, just as you describe, but was not called unification. My Allen theater had only three actual generators and one was a celeste. Flutes, reeds, tibias, and strings at all pitches from 16' to 2' were derived from just two electronic "ranks".

Others will expand. We love questions that let us discuss the basics.

[davidecasteel]

Older analog instruments usually only had one or two basic pitch generators, plus a special one for celestes. The basic generators produced tones with complex waveforms (usually either sawtooth shaped or square waves, but some used narrower pulses) and ran the ones switched by the keyswitches through passive filters (small circuits of resistors, capacitors, and inductors) that altered those basic waveforms into ones that simulated the sounds of other pipes or instruments. Using a steep low-pass filter on square waves, for example, generated what sounded like a stopped flute; a similar filter on a sawtooth wave might produce a diapason tone. Strings used high-pass filters and reeds needed tuned circuits to produce selective resonances. The celeste generator produced pitches that were slightly different from those of the basic generators in order to get the slight "beating" (less than 1 Hz) needed for those stops. They may have had a separate set of tone filters.

I guess one could say the process used by those old simpler instruments might be called "Filtration", and the method used to get the full set of pitches was often a set of frequency dividers: 12 top-octave pitches were produced by oscillators and those were divided down by 2s to produce the lower octaves. Although a much simpler and less expensive way to generate all 61 pitches required, all the octaves were locked in phase with each other and the output was less satisfactory (less rich) than in instruments where each pitch had its own separate oscillator (which meant they were not locked in phase). Of course, it was also a lot easier to tune just 12 oscillators than to do it for 61 of them.

Baldwins, Schobers, and similar organs used frequency division; Allen (for one) had lots of individual oscillators.

I'm sure others here will chime in with more information, most of it better than mine.

David

[mrdc2000]

To further complicate organ construction, both pipe and digital, many builders use techniques which are known today as:
- Unification, - Extensions, - Borrowing and Duplexing.
All four are used by most pipe organ builders. Some people call it cheating and it has a "bad" effect on the sound.
We know of a pipe organ locally that has a 3m console with 80 drawknobs but only 22 actual ranks of pipes, a true disaster.
A well designed "any" organ should always have more ranks than stops, for example, a 40 stop organ might have anywhere between 45-55 speaking ranks.
These same rules should also apply to digitals.
We invite experts among us to elaborate further on the four concepts. Thanks.

Many organ lovers often mention the beauty of sound produced by the old European pipe organs (those frequently recorded by Hauptwerk). That beauty of sound is because the 4 design flaws are not found in old trackers and hence are capable of true ensemble sounds, they are complete and lack no shortcomings.

[PeteKnobloch]

A well designed "any" organ should always have more ranks than stops, for example, a 40 stop organ might have anywhere between 45-55 speaking ranks.
These same rules should also apply to digitals.

From this statement it seems like you are not familiar with a Theatre Organ. Unification is the ability to play a rank of pipes at multiple pitches and from more than one keyboard. This means they share pipes on the playing rank. On a straight church organ this function would be talked about as Borrowing and was done using couplers and even through functions like a floating manual. A Theatre organ is highly unified and the organist needs to be aware which ranks are registered on each manual. Case in point: if the 8 ft. Clarinet rank is selected to play on the Great and Solo keyboard, and the A# key is being held on the Great keyboard, then pressing the A# key on the Solo keyboard will not change the sound since that note is currently being played. This is also true on the classical organ types where a coupler is used to be able to play a rank on more than 1 manual.

Pete

[Kurzweil]

I believe that mixtures (which combine two to four sets of high pitch pipes for that classic "full cathedral" organ sound) might cause the situation where there would more ranks than stops? Assuming a totally straight organ, of course.

Agreed that decent size theater organs (50 or 60 stops) can be ten ranks and the largest at 20 to 30 still are dwarfed by a large classical organ. The Atlanta Fox organ has a good deal more ranks but it contains a "classic" non-unified organ within it's theater trappings.

My favorite example of coupling is watching a tracker, or even a reed, organ being played with couplers on. You see the coupled pitches and coupled manuals actually playing "themselves", ala "The Ghost and Mr. Chicken".