Does anyone know of a way to adjust a bass regulator reed to prevent it jumping an octave on the low G? Upper notes are fine, the A is 80+% stable but the G consistently want jumps. The reed was made some years ago by Allan Moller and has a short tube slider at the bottom of the staple (narrower bore tube that fits in reed seat which reed staple goes over). Could this be the root of the problem.
Ian Lawther
Ian,
there could be several reasons for the Bass regulator notes wanting to jump the octave :
Chanter reed stronger that the Bass reed , so the amount of pressure is too high… adjust either or both to balance.
Too much stuff on the tuning pin ( or Rush) which disturbs the air column… , check that nothing inside the bore is too close to the note hole…
Key pad does not lift high enough and this causes shading of the hole which will exacerbate the reed’s natural tendancy to want to jump the octave… same as when the key is opened too slowly and just at the point of venting the note arrives in the overblown mode.
The head is not scraped enough, or not in all the places it needs to be.
The staple, as you suggest , could be a problem… so difficult to say without the thing in one’s hands.
There could be a leak somewhere above the G note, check for leaks.
Check also for blockages or leaks in the chanter and neck of the bag, which might cause you to be blowing harder than you need.
Oh, I could go on and on but… as you ask about the reed I will stick with that. It is best to make the bass regulator reed from very soft pliable cane, so the head can be thicker and less likely to want to play in the upper octave. This can be simulated by sticking a piece of Masking Tape ( or similar) to both scrape faces. Cut a piece of tape to the shape of the scrape, perhaps just a millimetre smaller all around and fix it to the scrape area, keeping back from the blade lips 1mm so as not to get the tape gum in the operating part of the reed.
If one thickness of tape makes no noticeable difference try a second layer.
This will have the effect of quietening the notes and ,usually, does not alter the pitch… hardly. This is a simple, after making fix that anyone can try… it is a tip I got years ago from Ronan Browne.
Sometimes people stuff a lot up the bores of the bass to quieten it… by closing the reed the notes will sharpen and get quieter but will then need more ‘rush’ to flaten them… in this way it is possible to obtain a balance… but often there is a downside… like octave jumping and destabilising…
Why this crazy instrument works at all is beyond contemplation… perhaps only due to the efforts of those who are obsessed by it… and the belief that it can be done!
Have a look at the pics of Ronan Browne’s reeds on NPU Source. The big gobs of blu-tak serve the purpose of quieting the reeds. I do this on my regulator reeds. As Geoff says, it hardly changes the pitch; but it is a handy volume control.
This doesn’t solve the problem of bass G jumping harmonics. You need a compliant reed and, because the bass G key opens relatively slowly (i.e., it has farther to travel before it lifts sufficiently from its vent to voice the note), you may also need to tap the key rather briskly.
Better still, make reeds. Regulator reeds don’t need to play the octave, so they are a good place to start leaning the handiwork.
It won’t be the tube slider, unless there is something extreme going on there. Having typed that, I realise that what is there is the opposite of what I do, so the staple bore in your case is going big small big. Not ideal. Try the reed without the tuning aid. I still don’t think it will be that though.
Good advice above, have you tried opening the reed up a bit?
Just wanted to follow up on this.
In addition the reed problem I also needed to do make a repair to the bass reg reed cap. My set has a wooden section at the base of the reed cap with an internal O ring. Many years ago this split and has been glued back together, with a cord binding to stop it splitting again. Since the last time I put a new bag on the pipes there has been a tendency for the the welt to push on this wooden part and loosen the reed cap. This weekend I finally completed turning a replacement wooden connector which is longer, so avoids the welt, and of course has no splits.
Having just played for the first time with the fixed reed cap I have found the with a little bridle adjustment the low G is much better at sounding correctly. I can also tell that the pipes are more air efficient…perhaps this was at the root of the problem. I will follow the advice above to get things exactly right, but as of now things are much better than they were when I first posted.
Thanks
Ian Lawther