Pipe Scales from Diyapason Archives thru 2001
Note from Keith: As you can see, the chart didn’t come out when I copied the archive into Wordpad. You might want to go directly to the archive and print out the chart yourself. Sorry.
Subject: Re: pipe scales
From: "Larry Chace" <
RLC1@etnainstruments.com <mailto:RLC1@etnainstruments.com>>Date: Mon, 15 Jan 2001 09:14:03 -0500
R. J. Siegel asked about pipe scales. Out of the depths of the = archives... >Date: Thu, 30 Apr 1998 11:20:49 -0400 >Sender: Pipe Organs and Related Topics <
PIPORG-L@CNSIBM.ALBANY.EDU <mailto:PIPORG-L@CNSIBM.ALBANY.EDU>> >From: Larry Chace <RLC1@cornell.edu <mailto:RLC1@cornell.edu>> >Subject: Scales of pipes and the measurement thereof Eric Sagmuller asked about the measurement of pipe diameters. From the archives of PIPORG-L we can find several postings on this subject. Two tables seem helpful, both based upon a standard scale such that the pipe diameter halves on the 17th pipe (starting counting at "1" and going up 16 semi-tones); this corresponds to a ratio of diameters of 1.68 (the fourth root of 8) at the octave, and in Germany this is referred to as the "Normalmensur". The American version of this scale includes "scale numbers" that correspond to particular diameters. The scale number is not dependent upon the pipe's pitch. The first table contains those entries that are most likely to match the bottom pipe of an 8' rank, assuming a rather wide variety, as you will = see: Note Sc Inch mm pi*Inch ---- -- ---- ----- ------ GGG# 40 7.28 184.9 22.86 AAA 41 6.97 177.1 21.89 AAA# 42 6.67 169.5 20.94 BBB 43 6.39 162.3 20.06 CC 44 6.12 155.5 19.22 CC# 45 5.86 148.9 18.40 DD 46 5.61 142.6 17.62 DD# 47 5.37 136.5 16.86 EE 48 5.15 130.7 16.17 FF 49 4.93 125.2 15.48 FF# 50 4.72 119.9 14.82 GG 51 4.52 114.8 14.19 GG# 52 4.33 109.9 13.60 AA 53 4.15 105.3 13.03 AA# 54 3.97 100.8 12.47 BB 55 3.80 96.5 11.93 C 56 3.64 92.4 11.43 C# 57 3.48 88.5 10.93 D 58 3.33 84.7 10.46 D# 59 3.19 81.1 10.02 E 60 3.06 77.7 9.61 F 61 2.93 74.4 9.20 F# 62 2.81 71.3 8.82 .... c1 68 2.16 54.9 6.78 .... e1 72 1.89 46.2 5.93 .... g1 75 1.59 40.5 4.99 .... c2 80 1.28 32.6 4.02 (This covers just about any 8' metal flue pipe used in theatre organs, and it therefore also covers those used in more traditional instruments as well.) The second table is the more complete one, showing all of the "standard" diameters for ranks from 32' pitch to 1' pitch (of 5 octaves compass). = The American scale numbers are shown only for the 32' octave; just as 12 for each column as you move across to higher pitches; 8' C is 44, for example. 32' 16' 8' 4' 2' 1' 1/2' 1/4' 1/8' 1/16' C 20 439.7 261.5 155.5 92.4 54.9 32.6 19.3 11.5 6.8 4.0 C# 21 421.2 250.4 148.9 88.5 52.6 31.3 18.6 11.0 6.5 3.9 D 22 403.2 239.8 142.6 84.7 50.4 29.9 17.8 10.5 6.3 3.7 D# 23 386.2 229.6 136.5 81.1 48.2 28.7 17.0 10.1 6.0 3.6 E 24 369.9 219.9 130.7 77.7 46.2 27.4 16.3 9.7 5.7 3.4 F 25 354.1 210.6 125.2 74.4 44.2 26.3 15.6 9.3 5.5 3.3 F# 26 339.1 201.6 119.9 71.3 42.3 25.2 14.9 8.8 5.2 3.1 G 27 324.7 193.1 114.8 68.2 40.5 24.1 14.3 8.5 5.0 3.0 G# 28 311.0 184.9 109.9 65.3 38.8 23.1 13.7 8.1 4.8 2.8 A 29 297.8 177.1 105.3 62.6 37.2 22.1 13.1 7.8 4.6 2.7 A# 30 285.2 169.5 100.8 59.9 35.6 21.1 12.6 7.4 4.4 2.6 B 31 273.1 162.3 96.5 57.4 34.1 20.2 12.0 7.1 4.2 2.5 These tables are only a guide, and various builders (even "factory" builders) may have assigned scale numbers that are slightly off these values. (And, of course, _many_ builders do not follows these scaling charts at all, choosing instead to vary the pipe diameters as best suits their artistic goals and the acoustics of the instrument's intended location!) When actually measuring a pipe, you _should_ measure the inside diameter, since those are the values given in these tables, but that can be difficult. Even using an inside-measuring caliper, you will have to be careful not to distort the pipe, and the pipe may not be perfectly round, so you may need to take several measurements. Some folks prefer to = measure the outside diameter and then adjust for the pipe wall thickness. If you use a small strip of paper, you can wrap it around the outside of the = pipe, marking where it overlaps; that will work even if the pipe isn't perfectly round. Of course, you will have to divide by "pi" (3.1415926535....) and then subtract twice the pipe wall thickness. On some ranks, you may find the scale number stamped or scratched into the metal, perhaps on the upper lip and perhaps on the back of the pipe near the foot. (But you still might want to measure, just in case the original builder had a different set of scales!) When trying to match up sets of pipes from different sources, you might = use the scale numbers as a rough guide, but it is the _sound_ that is important! There are _lots_ of variables besides the pipe's diameter and its length! It has been good to see some new folks with an interest in building their own residence pipe organs. There are actually quite a few people on this list (or who used to be here) with the same affliction. Larry Chace (RLC1@etnainstruments.com <mailto:RLC1@etnainstruments.com>)---------------------------------------------------
Subject: Re: [Residence Organs] RE: pipe scales,ep chest rebuilding
From: "Bart Kleineweber" <
prinzipal8@hotmail.com <mailto:prinzipal8@hotmail.com>>Date: Mon, 22 Jan 2001 15:36:37 -0600
Dear Steve and list: Steve Pitts wrote: >I have a couple of questions for the Organ Builders and/or otherwise >informed individuals on the list: > >#1 Approx how much would an Organ Builder charge to re-leather an EP >chest?How much would it cost me to do it? I have some old chests (1920?) >with the square pouches that need re-leathering.The magnets and = other >parts of the mechanism looks intact.I am wondering if its more practical = to >convert them to DE.If I buy a complete instrument at some point, (which = is >likely) I may get rid of the chests.I also like to think I might could = add >them to another Organ in the future. > Keep the chests, because if all it needs is releathering you may be able = to do this yourself. You measure the pouches and buy replacements from OSI along with the glue and simply remove them and glue in the new ones. There's bound to be someone on the list that has done this before. If you = do end up buying an intact organ you may want the chests to expand it. Converting to DE would not be practical, nor would it be efficient. It would require buying Reisner magnet and valves (about $350 for 61 of them, = tearing off the entire pouch board, closing off channels that go to the existing magnets, etc. Basically gutting the entire windchest and = scrapping all of the working parts so that all you have left would be the toe-board and starting all over to create the DE action. The result is also not as good as EP. This would only be practical if all of the action parts and magnets did not work and the only part of the chest that was usable was = the toeboard. >#2 Could someone explain to me why ranks of pipes of different scales are >incompatible?In what way are they incompatible?Most ranks of pipes I see >for >sale are not described in terms of scale. I Have the impression that the >scale of the pipe affected the tonal characteristics they produce.If this = >is >the case, this would seem to be more of an issue of the overall tonal >design of the organ. > Your tonal design you may want to decide for yourself. Pick out the style = of organ you think you want for the music you like to play. i.e., if you play classical and baroque you may want classical or baroque voicing, if = you play romantic literature the same applies and, of course, if you like Theatre organ music you won't settle for anything other than a theatre organ, although some have built theatre organs using church organ pipes. = As for scale, in the prinzipals/diapasons category the scales get larger as = the year they were built in increases. A 1700s tracker will have smaller diapasons or principals than a late 19th century romantic organ will and a = 1920s or 1930s church or theatre organ will have even larger diapasons. Generally speaking the scales are larger in the great than they would be = in the swell or choir divisions. In addition to being larger in scale they = are usually louder. Tonally, larger scales produce fewer upper harmonics and more fundamental tone and conversely, smaller scales produce better more refined harmonics and better brightness at the expense of losing some of = the volume of the fundamental tone. As for pipes going together or not going together, you wouldn't want to pair a larger scaled Octave 4 with a = smaller scaled Prinzipal 8. The scale should get smaller as the pitch goes up, a Superoctave 2 would be even a smaller scale than the Octave 4 and a = mixture smaller even still. Many of the pipes in classifed ads are not described with a scale, but rather a measurement of the largest pipe. You can determine the scale by comparing it with the scale charts in the OSI catalog. If they are not described either way, you can always write them and ask them. Sincerely, Bart Kleineweber Chicago, IL
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A pipe scale is based on the diameter or width of the 8' CC pipe. It is = the number of the corresponiding pipe in a set where a gigantically impossible = 8' CC is one meter in width and a halving ratio on the 17th pipe. A large 38 = scaled Open Diapason means you would go up the set to the 38th pipe and = that would be the diameter of your 8' pipe. For a scale 46 Open Diapason you would go up to the 46th pipe in your theoretical rank. The scale 38 Diapason would be much louder than the scale 46 Diapason for = the same wind pressure. The 38 would be duller in harmonics and the 46 would = be brighter. In adds the seller can sometimes just say, 8' Open 4"diam. 6"WP spotted = metal for the reader to understand that this is a small scale Diapason where the = first 8' CC pipe is 4" in diameter with a 6" wind pressure. A builder = would know from experience if the rank was useful for the tonal design being contemplated. Let us say you want a Baroque little sqeeker, which I love to build. You would go for small scales at lower wind pressures to work on your = mechancal windchests. The above Diapason would be fine for scale but the wind = pressure at 6" would be way too high. Voiced for 3" would be acceptable. Now you want more pipes to go with your first rank and the choices that must be = made are what ranks and how will they blend with eachother? All must be on 3" = and the scales will vary by how much power each rank is to have. If your next = rank is a Gemshorn rank that will blend and hold its own with the Diapason = so you can build up a chorus, a 3" diameter pipe would work. As you go for = more ranks you must rely on knowledge and experience to tell you what will = blend. Usually the tonal designer is the top finisher voicer in a shop. There is a reason some of us served 8 year apprenticeships! Best of luck, Al Sefl
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Dear Eric: Sorry for the delay in answering, I was trying to formulate a response = that would make sense and be helpful. Proper cutup is whole study in itself. = The cutup is a function of wind pressure, scale, and voicing for a specific timbre. It would be impossible via email to give decent advice as to how = you should or could raise the upper lip successfully. A voicer always first looks at the work of his predecessor when doing revoicing. You look to = see if the upper lip is directly over the windway (slit) or offset to give = more of the 3rd and 5th harmonics. You measure the height of the mouth in relation to the circumference. You note the wind pressure normally = stamped or scribed on the 8' CC pipe. A low cutup for a given pressure will tell = you the pipe was supposed to generate more harmonic content, etceteras. To = raise the cutup on a metal pipe is a simple process of using a draw knife on a scribe line laid out with a proportional divider to cut the new upper lip. = Wood pipes require a super sharp chisel and a steady hand with the idea = that you must also raise the top of the beveled area above the upper lip as you = go. The proportional dividers will give the line for the upper lip once = you have chosen the correct cutup you want to impart. The whole process is = time consuming and slow because you do not want to rush and make a mistake. = Then too you may have arched upper lips which give more fundamental from the 4' = octave up that you wish to match timbre. Without seeing and *hearing* the = pipes first I could not by email give you a good starting point from which = to work. See if you can contact someone in your area who can help with "ears = on - hands on" expertise. Sorry to not be able to give definitive guides but = organbuilding and voicing are still arts rather than sciences! Lastly, some metal pipes sag with age which causes the upper lip to bow outward. This will give you a more woolly sound of added harmonics. Your = 8' octave could just be in need of some general maintenance to bring the fundamental back to prominence. Best to you, Al Sefl PS: I am still trying to figure out what a "sunken languid" is? Do you mean a raised face with a step down behind
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