Several makers boast of perturbing the bores on their whistles. I was just curious as to how this is done.
I assume that the perturbations are changes in the inner diameter of the tube but when I look inside my my reputedly-perturbed tooters I don’t think I’m seeing anything.
Are the perturbations done with a boring bar or lathe or what?
Are they visible tho the naked eye?
Do I need to look harder?
Do I need to get glasses?
Do I need to get a life? :roll:
Anyway, any light that could be shed on this boring and perturbing topic would be appreciated.
The perturbation(s) are very obvious in my Burke aluminum and brass whistles. There is a ridge just above the C# hole on all of them and the low D has a very wide ridge at the bell.
My Burke Al Pro NB had no perturbations at all (at least not that I could see. [I didn’t really like it, as I stated in another post, so I sent it back but a few mix ups happened with the mail and with personal stuff so that it took a while so I’m just getting my money back]).
anyway, like cran said, as it is with every whistle, you have to like the sound. and he got his money back, even after the 30 days money back guarantee.
Hey Doc, Howdy. The perturbations are either constrictions or expansions of the bore in various places to bring the octaves into balance or improve certain tone holes or groups of tone holes.
I use rings of brass (or partial rings) of various thicknesses and lengths to achieve this and they are soldered in. The expansions are created by leaving gaps usually around the tuning slide.
lucky you, you don’t need all that stuff in your head anyway cran. leave the techno up to the builders.
fill your memory with music instead of techno and enjoy it and practice,
Quite poorly, but it will: soldering is not welding, just a warm “metal glue” of sorts.
But you’re generally right. It won’t solder with a reliable bond. And certainly not will bakelite (if thinking of Burke)… but both will find adequate modern cold glues.
Funny thing is most Quenas have a bore restriction, just at the end.
So do some Albas, with a less pronounced restriction.
You can call it a perturbation.
All it gets to, when you think of the “limit layer” effects of an airstream, is kind of creating a “virtual cone” for laminar flows in the bore.
As far as I can judge from Albas and quenas, having no experience with Burkes nor Reyburns, is that it works…
Also, Overtons (and all older square head/round tube whistles like the all-metal pre-plastic Generations) and recent Chieftains, as well as Albas, have a perturbation of sorts, but up there, next to the blade.
Now, to give back to Cæsar… Michael Burke was the first (to my limited knowledge) to call his alterations of the cylinder “Perturbations”. He should have registered such a nicely coined–and ain’t it perturbating?–definition.
Also, he seems alone to fit a restricting shim in the middle of the tube, not only down under or high up.
Not a problem – To be perfectly honest, I very much like reading Mike’s posts, so I try to encourage him to contribute.
My experience is that aluminum solders just fine. It’s certainly more difficult than copper – you have to be careful about surface preparation and use a good hot iron, the right solder (i. e., not eutectic), and the right flux. Aluminum also welds well, although that’s also tricky. Certain alloys don’t weld well, and again, the surface is important; for example, if it’s been sandblasted it generally won’t weld.
Hi Everyone,
Just saw the thread on Perts and of course, since they have always been a part of every Burke Whistle, I was interested.
I did not invent the idea of Perturbations, though I think I am the first one to apply them to whistles.
If you read Arthur Benades book on Music Accoustics, he explains their use.
Actually, the great makers of flutes and Recorders were using them 400 years ago, so it is just a rediscovery on my part after studying some articles on the measurement of many classic Recorders and Baroque flutes.
But the question I think that Doc asked and others was how they are attached, etc.
Whenever possible, I machine the perturbations into the bore, and in other cases where this is not possible, we machine rings that fit fairly snug and use super glue to hold them in. This works well, with only a very few ever coming lose and that after someone did some rather intensive plunging into the bore with sticks, etc.
As Renaldo said, the easiest way to add an expansion is by just cutting the tubes and putting in a coupling. Luckily only one expansion is necessary for my whistles to make them play perfectly in tune, but depending on the model, we may have as few as three and as many as 5 compression points in a bore.
It doesn’t make sense to put more things in a bore than necessary to make it play in tune and jump octaves well, so I always just work out each model individually and use what is needed for that key.
The perts are not supposed to be seen, since the ideal thing is to make it look like the design is as simple as possible and the stuff that makes it great are not visible, so that only the great sound when playing the music is seen.
I had a great visit with Brian Fineggan of Flook at Milwaukee Fest on night from 1:30-3:45AM and what I told Brian is what I believe. The whistles I make should not make people think- Wow, what a great maker Mike Burke is!, but Wow!, isn’t that great music that Brian is playing!!
Brian is a great musician and he is even a greater person and artist. He loves the music and is very humble about his own abilities. If you haven’t seen Flook, then you have not seen the hottest group around right now. Brian and Sarah are just awesome with the flutes. Sarah plays that big
Silver Alto Flute standing on one leg. She is not that big, but she is strong!!
Their latest CD is just fantastic too.
Well, I digress, but the point is not that we uses some gimmick to get attention, called Perturbations, but that they are one more tool to make whistles play well in tune and jump octaves cleanly after providing a strong , big round lower octave. All these things are a result of properly place Perts in the bores. I am delighted that thoughtful and talented makers like Ronaldo are applying them to their designs. If we keep working hard, Ronaldo, we may someday be as smart as those master Recorder makers who made those wonderful instruments that have survived hundreds of years to reveal their secrets, or at least some of them.
As, I think it was Solomon said, “There is nothing new under the Sun”.
We truly stand on the shoulders of Giants. It is humbling thing to discover how little we truly know, but delightful to rediscover something they knew and put it to work in a new instrument and be amazed at the music that is born from it.
I have seen, but not used, a speciality aluminium solder. I also understand there is an ‘araldite’ specially for aluminium, used in the aircraft industry.
