<HTML>Wim, Sorry about the late entry to this subject.  At NIU I have had the "pleasure" of replacing the damper systems on over a dozen S&S Teflon wonders.  The problems inherent in these systems cannot be remedied without replacing them.  However since I have many more of these creatures still in use let me share just some of what I have learned to be helpful. 1) Yamaha felt is probably the best to use.  We used to get it from Schaff, I am not sure they continue to carry it. 2) More smaller pieces of felt are better than fewer longer pieces.  I haven't really decided exactly where I will settle on this but so far I can tell you three 3/4" pieces in the bass section work much better than two.  Whether you put the third in the front or back doesn't seem to make much difference.  The last piano I put four pieces on had some weird harmonics which I eventually got rid of.  Keep in mind the more felt you put on the more room for alignment error exists.  The presence of the extra felt also adds about 1/2 gram to the weight of the damper head. 3) Weight.  I add it to the damper head itself, usually about 1 - 2 grams in the full sized dampers and as much as 5 - 6 grams in the cut down heads.  Solder for the lighter weights and old underlever weights for the heavier weights.  By adding this weight you will be able to decrease the amount of tension on the springs, (and don't tell anybody but I have left the springs off of some pianos with no ill effects.) 4) Geometry.  Because of the shortness of the damper arms they have a downward angle at rest.  It seems to me that the damper lever flange is supporting more of the weight at this angle than it would if the lever came to rest fully horizontal.  In any case your key end felt is getting pretty chewed up by now, messing up you timing. 5) String level.  Here maybe a truly artful compromise will help. Level the strings per the needs of the dampers not the hammers.  Maybe favoring the damper ever so slightly will not disturb the hammer too much and quiet the offending strings. 6) Threading the damper felts.  I use the same silk string sold by Yamaha for their hammer flange spring.  This can help in opening up the damper felt to meet the strings rather than closing the strings to meet the felt. 7) Bending the strings. A real last resort here but sometimes a little squeeze at the agraffe will bring the string closer to the felt.  (All of my pianos will be restrung in the next few years so I can live with this repair when it is absolutely necessary.) You mentioned a newer "B" with similar problems, I couldn't say if there is a relationship, however I can tell you these short arm Teflon wonders can be a real pain as they age, their inefficiencies become more and more obvious and troublesome. Andrew Remillard Northern Illinois University</HTML>