Forssell opto...ratio vs. resistance?

[DrFrankencopter]

Hi I'm looking at finishing my Forssell/Tommytones opto compressor (building it up with JFET 992s), and have opted to use a rotory switch for ratio control instead of the (difficult to obtain) 5k rev log pot.

If anyone who's completed one of these could give me the relationship between resistance and ratio (i.e. turn the pot to a few settings and measure the resistance and ratio), that would be great as it'll help me figure out what values I should populate my switch with.

Thanks,

Kris

 

[soundguy]

Kris-

Id help you out but I lent my finished unit to a friend to check out. Ive used mine on a few little things before lending it out and had just used a regular 5K pot and since its a ratio setting, I was never bother by the forward or reverse motion of the pot and it worked just fine. Id throw a cheap 5K pot in there and see if you mind andd then maybe measure that. I planned on putting in a switch but after using it with my test pot it turned out to be not a big deal at all. Maybe this isnt much help but thought Id comment, doesnt seem like many folks have finished this project up.

what did you wind up doing for the output gain control? I settled on a pot in the feedback of the output amp, seems to work pretty well so far.

dave

 

[DrFrankencopter]

Hi Soundguy....since I don't have a case designed for this thing yet I'll probaby take your advice and jig up a 5k pot (prolly a multiturn trimmer) and measure it.

For gain control I've potend for a fixed makeup gain (15 dB?) and I'll use a variable pad just before the output stage. Should be pretty simple....we'll see once apply power.

Cheers,

Kris