passive tone mod on a John East pre amp - please advise!!!

[Shonks]

right, here we go...i'll try and explain it best I can.........

my 5 string has the J East deluxe preamp and my 4 string has the regular J retro.

The difference between the two is the deluxe version has a 4th control which is passive and effects the overall tone wether in active mode or passive.
I love this, it's like having two basses in one. In passive mode it's just a regular passive bass - 'old school' on a switch!

In passive mode on the regular J retro, there's no tonal control in passive. Its still great, but knowing what I'm missing because of my other bass is getting me thinking.....

The deluxe has a small circuit board running from the pickup inputs of the pre amp and is effectively smoothing them down to earth before they hit the preamp. I assume the board's job is, besides attenuating the earth through a cap is also keeping the p'ups independent from each other - correct me if I'm wrong.

So it occurred to me, that if I put a regular passive tone pot after the preamp with a 250k pot and a cap of some sort, taking the single hot wire before it hits the jack output, that it should work in the same way as a regular passive tone, providing I only use it in passive mode.
I'm assuming in active mode the impedance might be a lot different and impact negatively on my active sound.

you reckon this'll work??

all advice welcome - please!!!

Edited April 22, 2012 by Shonks

[Shonks]

found this which answers my query,
[url="http://www.talkbass.com/forum/f38/adding-passive-tone-pot-active-preamp-431666/"]http://www.talkbass.com/forum/f38/adding-passive-tone-pot-active-preamp-431666/[/url]