"Black Keys" higher than "White Keys" on M48

Hey my fellow vibraphonists, I am wondering if anyone has had this problem before:
The damper bar on my Musser M-48 dampens the white keys sooner than the black keys when I use it. The result is an uneven feel, which presents more difficulty trying to play the instrument to make the subtleties stand out. (i.e. dampening, expression etc.) I have tried placing pennies under the two cross- planks that hold the white keys, but have found that this makes things more uneven horizontally (mid-range keys will dampen sooner than high and low ends).
Does anyone have a recommendation or a solution for this? It's a problem I have ignored for the last year or so, and after playing instruments that have an even damper mechanism, I have realized that my technique and sound are being harmed by not having a properly functioning instrument. For being such a "professional model" instrument, You would think that they would be made more reliably!
I'm all ears, so any thing you have to add would be much appreciated! -Dan

Hello- Here are two ideas that may help...

FELT PATCH- Buy some very thin felt that matches the color of the felt on your M48 (probably black or grey). You won't need much, but buy more than you need. Felt is very inexpensive. Cut a narrow strip (perhaps 1/2") that is as long as the damper bar, or you can use two or more pieces. Position the strip(s) under the "black" bars, but not under the "white." Don't glue anything this point. Gravity, the nap on the felt, and the tension on the felt from the bars will probably hold the strip in place. Now play away and see if that fixes the problem. If it works, then glue the felt strip in place. Wood glue or Elmers Glue will do the trick, but use the glue sparingly. After the glue sets, you can trim away any excess felt that hangs beyond the edge of the original felt damper. This will probably cost you less than $1 and may do the trick.

VIBES "CHIROPRACTIC" ADJUSTMENT- It sounds as if the damper bar or the arms of the damper bar are twisted slightly. You can try gently bending the arms a bit to put the damper bar in a more level position relative to the bottom of the bars. It is a bit unsettling to be doing this to your instrument, but if you take your time and adjust the arms slowly, you might be able to fix the problem. You can hold the arms in a vise to help you do this, but wrap the arms in cloth to keep the vise from leaving marks on the metal.

I have used both methods successfully to fix faulty, uneven, or old dampening mechanisms. (Note- Vibe frames are subject to torsional strain. Sometimes, if the floor upon which your vibraphone is standing is uneven, the dampening will go a bit off. You can shim the frame to make the vibes rest more evenly. I also carry little pieces of felt with me in my equipment gig-first-aid kit if I have to make a quick fix to the damper bars.

Good luck, Gary Miller

right on gary! you know your stuff!!

i think the posts start to bow down. right? sounds like that's what's happening. i know gary burton said he used to stick a pack of matches in the middle where the joint is that folds out. do you know what i mean?

are all the notes too low of too high? or only towards the middle. i would think it's just towards the middle.

Thanks Gary! I will try it out with the felt.
I've been trying the matchbook trick, and it seems to make a bit of an improvement, but it is so subtle. Sometimes its even all the way through, and sometimes, its not even from the sides to the middle. Every time I set it up things are a little different. It turns my practice time into half practice and half tinkering with the frame.