Hi Dale This echos my observations in general about Petrofs. Nice sound picture in general... sometimes a problem with falsness but a nice big round sound. But actions have problems. In one way its a field techs dream because you can make such a nice difference by really slicking out the action. As too your strike weights, ratio and BW. The friction you give, added to the general heaviness of the hammers is going to make the thing play like a truck. You are left with removing what hammer weight you can by shaping... removing staples... etc. or replacing heads. The 5.3 ratio if correct should actually nearly be up to the task of one quarter high strike weights. That is to say if you are going to use Stanwoods maximums for FW's and a 38-40 balance weight. That said, the heavier the hammer the more friction, wear and tear problems. If you can get them down to three quarter mediums I think you would find the existing ratio quite nice and you'd lighten up the whole scope of touchweight. I agree... the best option is new heads. Might I suggest getting them through Andre ? You can get origional colours and to some degree the overall dead weights you want. In anycase I ordered a set through him and they came out at one half mediums that I leaded up to three quarter mediums. The action plays quite nice now and looks origional. Cheers RicB Listers After a recent encounter with a 10 year old 6 ft. Petrof ,my once fairly high opinion of them has sunk. I generally have liked the sound of there bellies & the workamnship looked good but I had the following experience. The action although upon examination had a nicely done 5.3 overall action ration the touch was extremely heavy high 60's down & below 20 up. The problem is that the hammers were just way to heavy for example Note 16 was 10.5 grams. That's hammer wt. not strike weight. So extrapolate those heavier than normal readings thru the rest of the scale. Since the desired service was to make it play more like a Saturn than a truck & no parts were being changed the original parts were used. The remdey was to add one lead to a sparsely leaded keyboard & then adjust the wippen springs. Even at that the average down up weight was around 56 to 22 up which is a 39 balance weight. I believe the real solution was a lighter set of hammers & subsequent even leading applied with springs detached to some higher than normal nominal number down/up numbers & then re -tweaking the springs. for a light bit of wippen weight removal from the system. This to me was a prime example of a nicely done leverage set up that was doomed from the git go due to extreme hammer weights It seems all grand piano actions fall within certain reasonable & typical leverages that when exceeded are problematic until rectified by appropriate counter measures.
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