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Topic: Digital control of a Mic Pre (Read 782 times) previous topic - next topic



I'm interested in building a mic Pre and incorporating arduino for digital controls.  I'm looking at something like this:  http://www.seventhcircleaudio.com/C84/c84_about.htm

What are some ways to create a substitute for the fine adjust pot?  Or is this even possible?




Hi Loren

Do you know the part of the potentiometer they use for the fine trimmer?  There is probably a digital potentiometer you could drive (via SPI typically) via the Arduino.

The link to the bill of materials doesn't actually provide a list of parts...but if you know the part number a digital substitute might be identified.

Cheers  ! Geoff
"There is no problem so bad you can't make it worse" - retired astronaut Chris Hadfield


Ok so after your suggestion I did some looking. 

The part that they call for is this:  http://www.digikey.com/product-search/en?x=0&y=0&lang=en&site=us&KeyWords=91A1A-B24-D15L-ND

So would something like this work:  https://www.sparkfun.com/products/10613

Thanks for your help,



That one only has 129 steps so if you intend to sweep it in a logarithmic way like the original the steps will be quite course in your "fine" trimmer :)

It can deal with the power (400mW is rated higher than the 250mW of the manual one).  Unlike the manual one the setting is volatile, so it will forget where it last was on power off.  There are types that are non-volatile if you prefer, alternatively you'll need to code around its lack of memory by storing something in your Arduino EEPROM for example and putting the potentiometer back to that setting on startup.

Other than that, yes.
"There is no problem so bad you can't make it worse" - retired astronaut Chris Hadfield

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