Reed Sounds Twice?

[Peter]

My brand new Rochelle has a odd quirk, occasionally the left hand G row A/G key occasionally sound both the G and A notes. I suspect this has to do with the plastic flaps that cover the reeds (are these the valves?) Any help would be appreciated.

[Dana Johnson]

My brand new Rochelle has a odd quirk, occasionally the left hand G row A/G key occasionally sound both the G and A notes. I suspect this has to do with the plastic flaps that cover the reeds (are these the valves?) Any help would be appreciated.

That is an odd quirk. Usualy if a valve ( yes that is what they are ) is not working ( always open ) it just vents air by the active reed through the inactive one and makes the active reed more sluggish and quieter. Mostly reeds don't like to operate with the airflow going from the valve side of the reed to the tongue side. Sometimes you can get a little harmonic driving that will help sustain a reed going the wrong way, but from A to G and visa versa, that is very weak if existing at all. ( sometimes happens on the low b/g and g/c notes ( using your press draw convention) to a small extent )

 

Do you really get both notes clearly? Does it happen in either bellows direction?

What is more likely ( though I don't have a Rochell handy to check this ) is that the A/G chamber is adjacent to the G/A chamber( accidental row, one in from the end ) and you are getting leakage between them. I don't know how Rochells are constructed to know if this is even possible. Have a look and see if the pads for those two pairs of notes are adjacent to each other.

Dana

Edited March 2, 2007 by Dana Johnson

[Peter]

Do you really get both notes clearly? Does it happen in either bellows direction?

Yes, you can distinctly hear both notes being played and it only ever happens during the press, never during the pull (which is what made me suspect the valve for the A reed) I'll post some pictures of the pulled apart machine later tonight (or probably tomorrow, I need to sleep!)

I'll also have to check if there is leakage between any chambers

[Theo]

If it is brand new it would be wise to go back to your supplier first. If you take it apart yourself you may have invalidated your warranty. Take care.

[Frank Edgley]

The clue to your problem may be the fact that you say this problem only happens on the press. This suggests that it is the other G/A pad is being pushed open, at least partly, by bellows pressure. When you are playing on the draw, the pad is normally being sucked closed, and this suggests why it does not happen on the draw.

However, since you say the problem only happens when you play one note, perhaps there is another factor to consider as well. Otherwise it would happen on other notes. Maybe the pads are next to each other, and one is brushing against the other, tending to lift it. That along with the pushing action of the air pressure.

Another possibility is that the reed chambers of the two buttons in question are next to each other and there is a small leak between them. When the draw note is being played, no air can get into the next chamber because the pad is closed, and air pressure tends to hold the pad closed. However, when the bellows is pressed, air can get into the second chamber because the pressure can enter the second chamber and "blow" the pad open.

Edited March 3, 2007 by Frank Edgley

[Wally Carroll]

Peter,

The only thing that I would add is to make sure that it is indeed the A note that is sounding at the same time as the G. You may have heard two notes sounding and then assumed that it was the opposite direction note. It could be a leak in an adjacent chamber that is other than the Pull G/Push A chamber.

 

-Wally

[Dana Johnson]

If it is brand new it would be wise to go back to your supplier first. If you take it apart yourself you may have invalidated your warranty. Take care.

While going back to the supplier is a great plan, especially for advice on such a new instrument, I would be very suspicious of any concertina maker who's waranty precluded you from investigating it's innards. What are you to do about the stray piece of lint, or leather crumb from the bellows ( found in an early and excellent Dipper ) or cat hair etc. Unless a maker can guarantee a concertina proof against all the common ills that befall them, Their service better be mighty speedy, or their waranty accommodate the need to maintain the instrument. It is easy for them to include a phone number or contact email to ask how best to proceed when confronted by an issue with a new concertina.

Dana

Edited March 3, 2007 by Dana Johnson

[Peter]

The only thing that I would add is to make sure that it is indeed the A note that is sounding at the same time as the G.

Your sage advice has solved the problem (at least it hasn't come back in since I made the (hopefully) fix!) I originally had said G/A because those were the two notes on that key and I knew I was hearing part of a triad. Well it turns out I was hearing a part of triad, but I was misidentifing the extra note as A when it was in fact a D

With this new realization I opened up the instrument again, and there was the answer plain to see, scratch marks on the side of G/A button where it had been rubbing up against the adjacent C/D button's spring. The problem was that the spring was too wide, fixed by a combination of adjusting the C/D spring and filling off a wedge of the G/A button.

Thanks for the advice everyone. As frustrating as the problem was, I had a lot of fun concertina spelunking.

 

I would be very suspicious of any concertina maker who's waranty precluded you from investigating it's innards.

 

I would have to agree with that sentiment, but should note that I don't believe I ever saw such a stipulation in any of the documentation that came with the Rochelle.

Edited March 3, 2007 by Peter

[David Barnert]

I originally had said G/A because those were the two notes on that key and I knew I was hearing part of a triad.

I hate to be a spoiler here, but G/A is not part of a triad.

[Dana Johnson]

I would be very suspicious of any concertina maker who's waranty precluded you from investigating it's innards.

 

I would have to agree with that sentiment, but should note that I don't believe I ever saw such a stipulation in any of the documentation that came with the Rochelle.

I would have been astounded if it had come with such a stipulation. I don't know any makers that would say such a thing. They all back up their work or products, but sometimes retail outlets will have their own waranty, and that is less predictable.

Dana

PS, congratulations on the fix.

[Peter]

I hate to be a spoiler here, but G/A is not part of a triad.

You know what I mean (even if I don't )

[Woody]

I would be very suspicious of any concertina maker who's waranty precluded you from investigating it's innards.

 

I would have to agree with that sentiment, but should note that I don't believe I ever saw such a stipulation in any of the documentation that came with the Rochelle.

I would have been astounded if it had come with such a stipulation. I don't know any makers that would say such a thing. They all back up their work or products, but sometimes retail outlets will have their own waranty, and that is less predictable.

Dana

PS, congratulations on the fix.

For information - when I had a problem with a broken spring on my Rochelle I opened it up, found the offending part and took photos of it. I sent the info and pictures to Wim Wakker of Concertina Connection and he sent me some replacement springs and excellent instructions on how to fit one. At no stage did he make any suggestion that I shouldn't be opening the instrument up.

 

- W

Edited March 6, 2007 by Woody