Thanks Pls1, good post.
Re your hydraulic pump, the vast majority of the noise/vibration is coming from the pump side, not the motor (my guess would be on the order of 99%). Like I said, you definitely have to mount this system with isolation mounts, or put it in its own shed, but most are not that noisy since they are no noisier than two AC electric motors.
Re efficiency, I was just assuming 95% efficiency for the motor and the generator, which may be a little high, since the smaller ones probably aren't that good. So you may be right, 75-80% may be more accurate. Still way better than the 25% of a class-AB amp like the PS Audio unit.
For Tekunda, sorry if the above wasn't adequate explanation. A motor-generator is two separate pieces, (1) an electric motor, and (2) a generator. They are mounted facing each other on a single platform and hooked together by a straight coupling to transmit the rotation of the motor into the generator, which then creates the new AC waveform from scratch, just like a miniature power plant. They are completely electrically isolated from one another, which is why they give such good performance-- the power company's AC signal ends at the motor, and the generator creates a brand new one. I didn't point this out before, but they are immune to short-term power interruptions as well (up to a few seconds), since they carry a lot of inertial energy in their rotation.
Re your hydraulic pump, the vast majority of the noise/vibration is coming from the pump side, not the motor (my guess would be on the order of 99%). Like I said, you definitely have to mount this system with isolation mounts, or put it in its own shed, but most are not that noisy since they are no noisier than two AC electric motors.
Re efficiency, I was just assuming 95% efficiency for the motor and the generator, which may be a little high, since the smaller ones probably aren't that good. So you may be right, 75-80% may be more accurate. Still way better than the 25% of a class-AB amp like the PS Audio unit.
For Tekunda, sorry if the above wasn't adequate explanation. A motor-generator is two separate pieces, (1) an electric motor, and (2) a generator. They are mounted facing each other on a single platform and hooked together by a straight coupling to transmit the rotation of the motor into the generator, which then creates the new AC waveform from scratch, just like a miniature power plant. They are completely electrically isolated from one another, which is why they give such good performance-- the power company's AC signal ends at the motor, and the generator creates a brand new one. I didn't point this out before, but they are immune to short-term power interruptions as well (up to a few seconds), since they carry a lot of inertial energy in their rotation.