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Clive Thorne

Very 'Airy' high reed

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Posted (edited)

Hi all,

 

I have a C.Jeffries 36 Key Anglo, on which the first button on the right hand C row is a high Eb on the draw, and the F# almost an octave below it on the push.

 

The problem I have is that the Eb has always been very "airy". I am slowly getting more adventurous in my playing so am using it more often, so it's time to address it.

 

I've checked for leaks to the best of my ability  - If I block the aperture in the reed plate then there is no noticable leakage - but the problem remains. Also the F# on the push sound just fine.

I've tuned reeds, and set the hieghts before, but never done anything that involved moving the reed in the shoe, which is what I'm now considering, to try to make it a better fit in the shoe.

 

Any gems of wisdoms from the great and good of C.Net on what the problem might be, or hints on moving the reed?

 

Is it always going to be a problem with the pull and push being almost an octave apart? Would it be worth trying to reduce the chamber volume?

 

Thanks in advance.

 

Clive.

 

Edited by Clive Thorne

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Clive

 

I've encountered quite a few of these "airy reed" problems lately and the issue has almost uniformly been the gap between the reed pan and the gasket in the bellows frame being too large (as in, wide open).  I've cured it by shimming underneath the gasket and/or adding a small piece of additional chamois on the occasions that the gap isn't uniform along the frame.  Like you, I initially suspected reed gaps and messed around a lot before finding the issue.

 

I hope it's the same for you and that you find the cure!

 

Alex West

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First, don’t move the reed.  If you want to tighten the clearance, you’d have to shorten the tip to push it forward, then re tune by a fair amount since that pitch is reacting to such changes faster than low notes.  Then you have to be sure it is properly centered, and on a Jeffries that generally had pretty well made reeds, it isn’t likely going to get you much.    While Alex’s observation should definitely be checked out, I would be expecting similar difficulties with both the Eb and middle F#.  Of course, the large difference in pitch will  mean even with  the Airyness factor, the lower reed is still likely to respond better since it is already using more air to sound, so the loss percentage will be smaller.  It is also quite possible that the valve on the backside of the F# reed is staying open even a small amount at playing pressure.  Bob Snope of the Button Box in his great wisdom said he found most problems with reeds go back to valves.  Really, this just means that valves can cause a lot of problems, where other real problems with reeds are simply relatively uncommon.  Check the F#’s valve to make sure it is lying flat or close to it, not curled up or dried out and stiff.  Flap valve leathers used in older instruments  especially the white alum tanned leather while mechanically had good properties, degrades over time.  (It also very slowly gives off sulphuric acid vapor which corrodes the brass reed shoes it is next to.  
Dana

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10 hours ago, Alex West said:

the issue has almost uniformly been the gap between the reed pan and the gasket in the bellows frame being too large (as in, wide open).  I've cured it by shimming underneath the gasket and/or adding a small piece of additional chamois on the occasions that the gap isn't uniform along the frame

 

I have a Crabb EC where a previous owner glued a strip of card stock onto the outer edge of one of the straight sections around the reed pan.  This might be an easier fix than trying to lift up some glued down chamois on the inside of the bellows frame.

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21 hours ago, Clive Thorne said:

I've tuned reeds, and set the hieghts before, but never done anything that involved moving the reed in the shoe, which is what I'm now considering, to try to make it a better fit in the shoe.

 

 

I'd like to ask what method you used to set the reed gap/height?  In my experience very small high pitch reeds can only be set to the optimal gap by trial and improvement.   It can't be done done by just looking at the size of the gap. 

 

I'm also not clear about what kind of airiness you are getting?   Is it a continuous airiness while the reed is speaking, or a air passing before the reed speaks?  If the former it suggests air leaks, if the latter its more likely to be the reed gap.

 

 

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Thanks all for your thoughts ideas.

 

Theo, setting the height has been a lot of trial & error, but it may be worth revisiting before I get more drastic.

 

The airiness is while its speaking, so suggests a leak, but if I block off the Eb reed by putting a slither of paper under the reed shoe before I fit it then there is no sign of a leak. Hence my thought that it's a leak of air through the reed/shoe gap. I guess it could be round the edges of the shoe and the reed plate, but it seems a pretty tight fit. I may have another go at the reed height setting before I go any further.

 

Thanks again all.

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Bit of an update:

 

I swapped the Eb reed assembly with a C#  (below the Eb) reed assembly (same sized shoe) and the problem moved with the reed assembly. So to me that suggests the reed height setting, or a leak associated with the assembly (distorted shoe, reed clearance) rather than a leaky chamber or valve.

 

Also looking through the reeds the Eb does seem to have a significantly bigger gap around it than the C#, but, as per Dana's thoughts, I am reluctant to move and re tune the reed if it can be avoided.

 

Is it possible to buy a suitable replacement reed & shoe assembly from someone. The main problem I see with that is that there are so many variables: As above, the C# shoe was very close in size & fit to the Eb, yet the E shoe (a semitone up) was significanly smaller than either. It all seems a bit random. Could I buy an Eb reed/shoe assembly and then file the shoe to fit? Would this need to be a Jeffries reed/would I notice the difference if it wasn't? Who might sell me one?

 

Thanks again all.

 

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As Dana mentioned Jeffries reeds are usually very consistent which suggests that the reed tongue may have been replaced.  If that’s the case then I think the best course is to send the faulty reed to one of the makers who produce concertina reeds and ask them to fit a new tongue.

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Posted (edited)

UPDATE:

 

Well, bouyed by the thought that if all else failed I could get some one who knows about these things to fit a new tongue, I thought 'nothing ventured nothing gained' and went for it!

Ended up taking about a millimeter off the end of the reed in trial & error steps, using fine Wet & Dry. Turns out that the end of the original reed wasn't even square!  Pushed it forward in the shoe  which did close the side gap a bit.Took about 10 attempts to get it sat correctly and sounding (and fully clamped down). By this time it had gone sharp by about  a semi tone sharp so tuned it back down to Eb.

 

Result is that it is sounding stronger and less airy. Ideally I'd take it a bit further, but am going to leave it as it is for the moment.

 

So far so good!

 

Thanks for all your thoughts and suggestions people.

 

Clive.

Edited by Clive Thorne
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