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<blockquote data-quote="John Roberts" data-source="post: 100865" data-attributes="member: 126">Re: New line of StudioLive AI mixers announced.No they don&#039;t use stepper motors, especially the inexpensive motor-faders. They typically use basic forward/backwards DC permanent magnet motors. A linear resistive fader element is connected across a DC supply and the fader wiper returns a fractional DC voltage that represents it&#039;s positional information. Pretty simple basic positional servo where you tell the motor to run until you get to the destination wiper voltage, while actually the software is tuned to model inertia and ballistics of the moving fader so it doesn&#039;t over-shoot, under-shoot, or hunt around... Not rocket science. Harder part is making it survive mechanically under the abuse and conditions it&#039;s likely to get exposed to. Hint it isn&#039;t likely to wear out from 300,000 cycles of simple up/down fader moves. More like several spilled beers and peanut shells trashing the drive belt. But like i said if they are cheap and easy to replace, that&#039;ll work too. The 300k vs 1M Midas comparison seems exactly what the customers would expect. Who knows maybe it&#039;s true? Not a precise science to predict actual in use life, while real pot manufacturers do actually spec normal controls like pots and switches that way.&nbsp; And it&#039;s not big deal to make a fader sit there and ramp for a week or so...JR</blockquote>

[QUOTE="John Roberts, post: 100865, member: 126"] Re: New line of StudioLive AI mixers announced. No they don't use stepper motors, especially the inexpensive motor-faders. They typically use basic forward/backwards DC permanent magnet motors. A linear resistive fader element is connected across a DC supply and the fader wiper returns a fractional DC voltage that represents it's positional information. Pretty simple basic positional servo where you tell the motor to run until you get to the destination wiper voltage, while actually the software is tuned to model inertia and ballistics of the moving fader so it doesn't over-shoot, under-shoot, or hunt around... Not rocket science. Harder part is making it survive mechanically under the abuse and conditions it's likely to get exposed to. Hint it isn't likely to wear out from 300,000 cycles of simple up/down fader moves. More like several spilled beers and peanut shells trashing the drive belt. But like i said if they are cheap and easy to replace, that'll work too. The 300k vs 1M Midas comparison seems exactly what the customers would expect. Who knows maybe it's true? Not a precise science to predict actual in use life, while real pot manufacturers do actually spec normal controls like pots and switches that way. And it's not big deal to make a fader sit there and ramp for a week or so... JR [/QUOTE]

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