List, Just finished my first celesta ( Jenco) repair and regulation. An interesting learning curve to say the least. Thank you Fred for your helpful insight as it helped reduced some serious head-scratching. Work completed: Removed and serviced all 3 racks of tone bars and hammer mechanisms Installed hold down screws for each hammer flange ( all were a glue-in type and and all had come unglued). Very similar to the older Steinway backaction glued-in damper lever approach. Rebush key bushings Restring tone bars ( all strings were broke) The suggestion was to not restring with the nylon type string, but use fishing monofilament 80lb test line. Supposed to have good wear and better resonance Replace damper felts, and a made a small dampening improvement to help with better dampening. Regulate action ( again, thank you Fred Sturn for his advise). Since there is no let-off, the trick is to find a sweet spot between hammer blow and key dip. The hammer cannot block against the tone bar in a fff blow so you have to play around with the relationship between blow and dip until you find a good measurement. I ended up raising the key height a tad, then ended up with a 11.5 key dip and a 43mm hammer blow Regulate damper lift, (very problematic system) Did not get into tuning the tone bars. So a few thoughts: 1. With the advancement of the piano action already developed by the time celestas came onto the scene, why on earth didn't Jenco take note of the piano mechanism and incorporate that into their design? I can't speak for other celesta manufactures, but this particular design is archaic at best. 2. Celesta's in general, have a heavy clunky feel their action. I had assumed that's because of a cumbersome mechanism. No, its because there's an incredibly tight return spring. Plus with very flimsy made keysticks, you couldn't even begin to weight-off the action in the traditional piano approach. Again, they could have taken note of what the piano community had already figured out and incorporated the piano design into their system. 3. I realize there aren't a lot of celestas out there. And I'm sure this probably would not be cost prohibitive, but I would think someone could design a let-off system that could be incorporated in the Jenco design. Again, I can't speak for other celesta manufactures, but the Jenco design is begging for someone to step forward and bring this up to a better level. And these aren't cheap. I was told that the good 5 octave Yamaha and Sheidmayer celestas are in the $45,000 range. Used 3 octave Jenco's in reasonable condition are in the $9,000 range. My client found this in horrible condition for $2500, so he's thrilled.