I'm thinking of going stereo and have been looking at the Ernie Ball stereo volume/pan pedals.  Two questions that pop up are:
 
1.  The Ernie Ball pedals come in two types  
    - 250k potentiometer for passive  instruments                                                    
    - 25k pot for active instruments
 
I've been using the same old basic Ernie Ball -built like a tank- mono volume pedal for all my guitars and haven't noticed a difference when I use my Alembic.  How important is the 250k v. 25k option?  What difference does it make.  Any input from the electronically knowledgeable types would be greatly appreciated.
 
2.  Any suggestions or recommendations for a stereo volume/pan pedal other than Ernie Ball?
 
I shall now kick back and await the flood of knowledge that will surely come my way.  Thanks everyone.
 
Bill, tgo
 

O.K., so no one is interested in volume pedals - (of course you're mostly just a bunch of low end types anyway - hehehe).  At least can anyone explain to me the 250k passive v. the 25k active?
 
Bill, tgo

Well, for example...
 
Fenders generally use 250K ohm volume pots on single coils
 
Gibson was using 500K ohm pots on humbuckers
 
EMG uses 25K ohm volume pots, thus the idea that active = 25K ohms
 
I suspect that the theory of offering two pedals is that it is most effective when it matches what is on your guitar.  
 
Check out this page for some useful info:
http://www.blueguitar.org/new/schem/_gtr/gtr_wiring-stewmac.pdf
 
What I don't know is the spec for an Alembic volume pot.  
 
From what I think I comprehend of the research I just did, if you're using the pedal mostly for on/off, I'd go with the higher number anyway.  If you're trying to fine-tune your volume, you may have more flexibility with the active pedal if your guitar uses a 25K ohm volume pot.

Have you looked at the Morley pedals ? I believe they're optical rather than mechanical.

I don't know anything about volume pedals; but the optical idea appeals to me as I seem to recall that they are quieter than the mechanical pedals.

I have an Earnie Ball Stereo Volume pedal and the only thing I don't like is the fact that this pedal don't make a 100% close. You still can hear the tone when taking it off. I had a mono version of this pedal some years before and didn't have this problem with the mono version. Otherwise it's a great pedal.  No noise at all.
 
Harald

Long story short:
 
Active electronics have a much stronger signal than passive.  Because of this it can drive a bigger load.  A 25K pot applies a 10 times greater load to your instrument than a 250K pot, and would be a problem for a passive instrument.  You could use the 250K pot on an active instrument but this would effectively make your signal passive downstream from that point so you would lose the benefits of being able to drive a long cable and feeding your active input on your amp.
Hope this makes sense...
- SoM