The servo noise is pretty common on a lot of servo systems. It depends how "hard" they are tuned. If you go for a soft tune, ie lower gains, lots less D, then the noise goes away but the response is nowhere near as good. Its all a compromise. If you can use encoders with more counts per rev, then its less of a problem. These ones are 12 000 counts per rev (3000 lines) or about 1 micron resolution. The new Fanuc machines and some other systems Ive used use million count encoders or sine/cos systems like Hyperface or endat or BISS and they are a fair bit quieter and more responsive. But 10 times the price. Really they should be quiet but its hard to achieve in all cases. I did have an even "harder" tune but it was tripping the drives sometimes, so I pulled it back a bit and its ok now, but like you say a bit noisy. I will look into it a bit more. Ive done lots of tuning with the DSPMC and havent seen much if any effect from the feed forward terms. Ive used feed forward (position control lagless they call it) on a big system with Beckhoff Twincat and its awesome. Hopefully Rufi can help us with the feed forward stuff.