I have an almost new Yamaha P-121 - this is a truly wonderful compact digital piano. I have made a couple of gigs with the instrument, using Roland DP-10 as sustain pedal. For some unknown reason the Roland won't work anymore with the P-121. No luck with the polarity switch or depressing the pedal when powering on the piano and I have tested with two different DP-10's. The poor flat Yamaha switch that was delivered with the piano worked still OK. According to some information I found, lots of other people have had the same problem with various Yamaha pianos and the general advice is to primarily try to use Yamaha's sustain pedal. And yes, it works right away. Now it seems that this FC-3A is the optimal product for P-121 and P-125, probably for some other Yamaha pianos as well. It is possible that the half damper functionality won't work with the newer FC-4A model. I haven't been able to verify this information but the Yamaha service in my country also indicated this detail.
As for the FC-3A itself, it is quite sturdy. The pedal part is made of trustworthy metal and the mechanism seems solid. Half damper functionality activates when the pedal is pressed quite low, not in the middle part in the movement as in some other sustain pedals. So there is not very wide range where the half damper functions. This isn't a minus however. I yet have to experience how will the FC-3A stay in place on stage. I don't know if FC-3A's small rubber feet are enough to prevent the pedal sliding forward on slippery surfaces. I have purchased StageWorks NonSlipMats to help in that anyway.
