changing the values of 'digital pots'...or a good source

[enthalpystudios]

i'm in the planning stages of a piece of gear with all digital control, a pic that will drive Dallas digital pots.... ok it's a guitar pedal, not on the usual menu here at prodpro, but I'd feel better asking here than anywhere else (aside from an EE friend who's completely unavailable 90% of the time)

only problem is i need to replace quite a few VR's, and their values are....

1M log
150K log
(2) 100k log
(3) 100k lin
25k lin
(3) 50k lin
1M rev log
10k lin
1M lin
20k lin
500k log
50k log

.... yeah, i know....

but i'm determined! even if it takes me years.

anyway, these dallas digital pots only come in 10k, 50k, and 100k

Maybe someone knows of another brand that come in more values?

Is there a way to make one 'act' like another value, or should I look into using another solution like a vactrol or relay/resistor array?

I'd go with vactrol type deals, but I think they can have a kind of high min. resistance, don't they?

and I feel that relay/resistor arrays are probably too physically large if I need 17 of them.

Anyway.... someone with real (not hack) knowledge would probably do it some other way, I suppose.

billy

 

[bcarso]

I think there are some really high resolution multiplying bipolar D-to-A converters which you could create the appropriate code for to emulate most of these, except maybe the 150k and 1M.

But a more reasonable strategy, probably, would be to look at each circuit location and determine if the variable controlled by the pot in that location could be controlled in a different way.

 

[enthalpystudios]

yeah thats what i was thinking as well. Try and make everything work with different values. there's also a good chance most of the controls don't need the range specified as well.