AMZ Mini Booster question

[smallbearelec]

So, Does anybody have a part#/Source for a Linear taper, 50K, D-shaft (for wah) pot.  Hardware/gear and mounting/bezel size to work as a wah pot is wanted!!  I would expect Mouser has it

Naaaa...pots that are compatible with expression pedals are a specialty item. I don't recall what the taper is on this one:
http://www.smallbearelec.com/servlet/Detail?no=1262
but I will check for you when I'm back in the shop.
SD

The Dunlop pot turns out to be audio taper...sorry!

SD

[italianguy63]

Don't fret Steve.. it may still be the solution.  a 50K audio is better than anything I have right now!!  MC

[armdnrdy]

I built a AMZ Mini Booster with the purpose of using it as a clean boost/volume pedal.

I mounted it in a Crybaby pedal, and used the stock crybaby pot.  It (sort of) works.  Of course the volume gets touchy fast because the Crybaby pot is 100K-Log.  Obviously, I need a Linear.

Question is:  To make the pedal go from zero volume to some level of boost, in a pedal type (not full deflection of the pot) environment-- What value pot would be ideal?  Would it be larger (125K?) or smaller (50K?)... or maybe smaller with at fixed resistor in line?  i.e. 50K + 50K?  

Thoughts?
MC

You can make this work with a vactrol, (LED/LDR) a small amount of supporting circuitry, and almost any value linear pot.

You should have plenty of space left in the wah enclosure.

Look for optical volume pedal circuit. I believe Craig Anderton designed one.

The LDR will take place of your volume/gain pot of the AMZ mini booster and the wah pot will control the LED which will change the resistance of the LDR.

[duck_arse]

the anderton mod is somewhere on geofex, of course.

[italianguy63]

I looked at it.  It is a bit more involved than what I really want to get into.  Steve got an order for a couple of pots for me to try out.  I should be able to make them work.  I also tried the jumpered 100K Hotpotz.. it was still too critical.  A standard audio slope would be preferable to a W slope wah pot.  And linear better yet.

[armdnrdy]

If the pot doesn't work out...look into the use of a vactrol.

The Anderton mod probably isn't the best example....I just mentioned it for reference.

A pot controlling a vactrol LED which in turn controls resistance can be accomplished with much less parts.

The same type of circuit is used in tremolos, compressors, etc. but instead of a LFO controlling the LED, a physical potentiometer is.

Here is a vactrol application PDF for some better examples:
http://www.excelitas.com/downloads/app_analogopticalisolatorsaudioapps.pdf

[italianguy63]

The 50K Log still is touchy/steep.   

More experientation on the horizion.  MC