Interesting project

[ajay_m]

https://www.instructables.com/5-Fader-P ... -Motorize/

Now you can purchase 5 packs of x32 motorised faders for just over 30 quid, some interesting possibilities arise, as in this project. Very clever ...

[onre]

If only these were audio taper! The project I had in mind was adding flying faders to my old analogue desk. Of course I could build a bank of 8 VCAs... so many ideas, so little time.

[Wonks]

If you are able to edit the downloadable code, you can convert the linear value from the faders into a log curve value before sending its value out as a MIDI message.

[onre]

If you are able to edit the downloadable code, you can convert the linear value from the faders into a log curve value before sending its value out as a MIDI message.

Indeed. However, my pipe dream was to replace the group faders on my desk with these, retaining the current analog functionality and also being able to control the faders by sending MIDI messages to the desk. The group faders of my desk are in the signal path, so accomplishing this would necessitate either audio taper faders or building a VCA bank for the groups so that a linear-attenuated control voltage from the faders would result in logarithmic changes to signal level.

[Wonks]

There are more expensive options available, such as Penny and Giles motorised faders but whether they’d fit in the existing space available is another matter.

[Folderol]

If you are able to edit the downloadable code, you can convert the linear value from the faders into a log curve value before sending its value out as a MIDI message.

Indeed. However, my pipe dream was to replace the group faders on my desk with these, retaining the current analog functionality and also being able to control the faders by sending MIDI messages to the desk. The group faders of my desk are in the signal path, so accomplishing this would necessitate either audio taper faders or building a VCA bank for the groups so that a linear-attenuated control voltage from the faders would result in logarithmic changes to signal level.

If you have a very low impedance source you can get something vaguely resembling a log law :

---------[pot]----------------------------input of destination with (say) 1/20th pot value to ground
. |_____|wiper

[Folderol]

If you are able to edit the downloadable code, you can convert the linear value from the faders into a log curve value before sending its value out as a MIDI message.

Indeed. However, my pipe dream was to replace the group faders on my desk with these, retaining the current analog functionality and also being able to control the faders by sending MIDI messages to the desk. The group faders of my desk are in the signal path, so accomplishing this would necessitate either audio taper faders or building a VCA bank for the groups so that a linear-attenuated control voltage from the faders would result in logarithmic changes to signal level.

If you have a very low impedance source you can get something vaguely resembling a log law :

---------[pot]----------------------------input of destination with resistor (say) 1/20th pot value to ground
. |_____|wiper

[ef37a]

If only these were audio taper! The project I had in mind was adding flying faders to my old analogue desk. Of course I could build a bank of 8 VCAs... so many ideas, so little time.

I cannot find the track value for those faders but you can convert lin to log (sort of) with "law distorting" resistors. Check out Duggie Self's book on small signal circuits.

If the track is say 10k the resultant resistance gets a bit low for some op amps but the NE5532 or better will have no problem.

Dave.