Buzzing damper straps

[Bartman]

I am restoring a 1971 / 73 stage piano.  I have replaced all the ususal stuff, felts, grommets,hammer tips and installed back check mod.  On the lower half of the key board I am getting buzzing from the damper straps.  It is not very musical and it can be heard through the amp via the pick ups.  Any one have a suggestion on how to stop this vibration?
TIA

[pianotuner steveo]

It sounds like the tension needs to be changed-this is done by carefully bending the metal damper arms. Is your escapement too high on these notes?

[Bartman]

It buzzes as the dampers tries to damp the tine when you let go of the key.  I don't think the escapement is too high but I am not an expert.

[jim]

I agree with steveo about the tension not being enough.

if you unscrew a damper arm and look at it from the side it should look flat from the screw hole to the back of the bridal strap tab,  not bent down.
if it is bent downward you can straighten it or even bend it upward a little and this will give the damper a lot more stopping power, which is useful for those longer tines at the bottom.

[Bartman]

If I raise the pressure for deeper engagement of the damper straps, won't I loose the  sustain?  The manual mentions that the damper felt should clear about 3/8 which it does, if I increase this will I loose my sustain?

[jim]

when you say damper straps are you reffering to the metal arms or the cloth straps (the bridal straps)?

by increasing the tension you are just increasing the pressure that the damper puts on the tine and how quickly it gets back to the tine.

bending the damper between the mounting screw and the bridal strap shouldn't change the distance between the damper and the tine when the key is depressed, so it shouldn't effect your sustain.

if you bend the damper arm on the keyboard side of the bridal strap, this will effect sustain.

a lot of pianos from the early 70's will have damper arms that have gradually bent downward over time (just from the bridal straps pulling on them and the sustain mechanism pushing them down) and have lost their spring back skillz because of this.
so to bend it straight is to bring it back to its original state.

[Bartman]

Thanks all that responded, I will take the sucker back apart a try to increase the tension on the damper straps. I will let you know. I feeling like it needs a zipper.  

[jim]

haha yeah totally! the harp off harp on harp off thing gets real tiresome.

[Bartman]

I retentioned all the bridal straps, but still was getting buzzing in the middle of the keyboard, I ended up having to move the harp back on the bass side that got rid if the buzz broblem.

[Chris Carroll]

Buzzing dampers:

This is common with old dampers-

Possible causes of buzzing-
1.Dampers are hitting the damper rail underneath before the felt rail edge.
I have seen this before, you will have to sand down part of the extrusion thats hitting the dampers, you will notice marks under the damper where contact is happening..

2.- Fast bounce or flap can cause noise, I am not sure about a buzzing, this to me sounds like metal on metal. But none the less exssesive bounce caused by weak dampers can cause noise.

We have just released our new Fender Rhodes Dampers, have a look

http://www.vintagevibe.com/p-703-fender-rhodes-dampers-new.aspx

They are just great!

[Bartman]

They look awesome will replace some of mine next time I have problems.