Active PUs:what pots' values?

[Le Basseur]

Hello all,
I have a pair of MEC (German brand,as found on Warwick basses...in fact,EMG clones) P+J active PU's wich I took out from my Streamer bass.Being active,these PU's were driven by a 9V battery wich also powered the onboard active,2-way original preamp.
I'd like to put these active PUs in another bass (a cheap Squire needing an upgrade) but I'd want to make a simplified wiring,since the 2-way preamp is gone as well as the original pots.
For a better reference,here is a similar comercially-available product made by EMG:
http://www.emginc.com/displayproduct...&categoryid=24
As you can see,the EMG sells the complete story,pots&wiring included.
Since I have only the PU's and I'd want a "classic" vol+vol+tone config - of course,the active PU's powered as needed - BUT without a dedicated onboard preamp,my question is:
What's the appropriate vol+vol+tone pot values to be used with such active PUs?
I heard some claims about these EMG pots (for active PUs) being 25 Kohms but others say that any pot value between 25K and 100K should be fine.
What I primarily intend to find out is a tech explanation of the reccomended 25K issue:why's that,why an active PU needs such a low value?For the vol pot,is the 25K value critical,or,as a matter of fact,could I go with larger values?And,lately,what should be the tone pot's value?
Thank you in advance!
Regards,

[Steve Conner]

Well, one important feature of active pickups is that they offer a low output impedance, which allows driving long instrument cables without losing treble. If you use a high-resistance volume pot, you throw this advantage away.

The pickups themselves probably don't care about the resistance of the pot, as long as it's not so low that it overloads the internal amp. So you want to use a good low value to keep your treble.

A good starting point might be to take the usual values from a passive instrument and divide all the impedances by 10. So a 500k volume or tone pot becomes 50k, a 100pF bright cap becomes 1000pF, etc.

[Le Basseur]

Thank you Master!
Regards,

[David Schwab]

Actives generally use something in the range of 25K to 100K. EMG uses 25K, and Basslines use 100K. I've used 250K with EMG's in a pinch.

But 50K to 100K should be fine. What's in the original bass?

[Le Basseur]

What's in the original bass?

They're 500k (Squire PBass Special flimsy originals)...obviously,I'll have to change them with lower values and better quality.
Also...thanks for posting!
Regards,