'after-Buzz' On Wheatstone Metal End

[varney]

I have a metal end Wheatstone which is in need of some work and one of the problems is quite a pronounced 'afterbuzz' ( the only accurate description I can give ) which happens directly after some notes are played.

 

It's particularly noticeable on the lower notes on the left side ( low C, G, F etc) Right after the note plays there's a metallic sizzle or buzz which to my ears sounded like a vibration going through the longer levers.

 

As an experiment I attached some small pieces of cloth tape around the longer lever arms to deaden any buzz or after-ring, but it doesn't seem to have solved it.

 

I wondered if the grill end was doing it in some way so attached some felt pads inside at a few points to mute any possible buzz. Again this did nothing.

 

Has anyone ever encountered this problem before and have any advice?

 

Michael

PS I want to make clear it's not loose reeds as I've checked all these. It's more a 'zingy' after-tone which is loud and sharp directly after certain bottom notes on the left side are played.

[Geoff Wooff]

Loose reedpan ?... Perhaps that would not make a 'sharp' sound.

 

More likely to be the Valves that are continuing to vibrate after the reed has stopped... So look closely at the valves for the the offending notes... some valves are incompatible because they are too springy ( or perhaps the wrong weight/thickness) and can act like semi- reeds.

Edited May 11, 2014 by Geoff Wooff

[Graham Collicutt]

Blocks supporting reedpan loosening, or just a leaking pad.

[sqzbxr]

Check for loose handrest screws.

[Mike Franch]

I don't have quite this problem but something similar with my metal ended Wheatstone Model 21, and a friend with the same model (although about ten years newer) seems to have a similar issue. Individual notes play perfectly well, but playing some cords produces a metallic buzz. For example, on the left side of my EC, G plays perfectly well, and B plays perfectly well, but if I play them together, there's a buzz.

 

This is a somewhat different problem, so pardon me if this introduces thread drift. It seemed at least a cousin to the presenting problem

 

Mike

[varney]

Thanks very much folks - all useful suggestions.

 

I looked at each in turn but none seem to be the source of the problem. One thing I did notice is that the pads were very thin and hard so I changed them in case these were vibrating against the wood and causing the levers to oscillate in the pivots. This has helped greatly and I'm only finding that the G/B and C/G on the left centre row still have an after buzz.

 

Mike - your problem does sound like mine. I'm wondering if it's a frequency which is setting off something somewhere. It reminds me of a snare drum on a stage that will rattle when certain bass guitar notes are played!

 

Any further suggestions most welcome..

[Chris Ghent]

Does it only happen when you play both of the notes on those buttons, a bellows direction change without lifting the button? If so it is a valve issue. The valve beside the incoming reed would need changing for one with a greater desire to return home and stay there.

[varney]

Yes, Chris, it's happening for both reeds on each button. There's also still a hint of a buzz around some of the other reeds in the lower end, but it's not as pronounced as before.

 

Thought I had solved it when I realised there were two domed metal screws in the action box put there to substitute the grill support dowels. I thought these must be zinging against the metal grill but despite removing them the sound is still there.

 

Doh!

 

I think a valve refit for all the lower reeds is the next move in trying to eliminate all possible causes....

[Chris Ghent]

Just as an indication, take off the valve opposite the reed which leaves the greatest after-buzz and reassemble the instrument. The concertina will still play OK, and if the after-buzz when coming from that bellows direction has gone then you will be more confident about the valves being the issue.

[Dana Johnson]

If replacing pads with thicker softer ones eliminated the problem, and given that you called it After buzz, it sounds more like the low relatively massive reeds are causing some vibration at the action ( pad ) board. Reeds stop sounding when you take pressure off the bellows or otherwise shut off the air flow. They vibrate in the frames after that and that vibration gets transmitted to it's surroundings which eventually damp it out. If you have hard pads and lighter spring tension, the normal vibration tail off of the reed can cause anything with a similar vibrating frequency mode to bounce up and down. This can affect both the leather flap valves or the pads/lever/spring system. Or as you tried, metal ends on makeshift spacers. I used to make and repair violins and violas. A scratchy or buzzing tone was a good indicator of a plate coming unglued. If your action is light, thickening the pads will both damp out the buzz to some degree, but also put more tension on the spring holding the pad down more tightly.. Different parts of the concertina have natural resonances. If a reed is near ( physically and in pitch) to one of these, the concertina can vibrate a surprising amount.. Buzzes can originate far from the source of the sound too since resonances generally occur in patterns over the area of a structure, one bit moving up while the other goes down in a cycle. Interesting to watch with a strobe and some glitter. ( interferes with the reeds unfortunately)

[Noel Ways]

Hi

 

It sounds to me like you have a humidity problem that is effecting the wood reed pan by ever-so-slightly changing shape with changing humidity. I do have this problem with my concertina, where I will get buzzing sounds when it is really dry or very humid. The way that I control this is that when the concertina is not in use, I will store it in an air-tight container with a Saturated Salt solution in another small plastic container in an isolated area to control the relative humidity. Here is a chart that will help to determine what salt to use for a maintaining a desired relative humidity:

 

http://www.omega.com/temperature/z/pdf/z103.pdf

 

There are many more articles on the web for this subject, and several that addresses musical instruments, such as violins. (Google: "relative humidity saturated salt")

 

The fact that this is happening to a cluster on notes on one side strongly suggests that humidity is the issue; and if it is happening on the push and pull - then think HUMIDITY !!

Edited May 26, 2014 by Noel Ways