FET buffer/MOSFET booster with positive ground

[gigimarga]

I had tested my germanium Fuzz Face with a buffer (and after that with a MOSFET booster) in front of it and i like how it sounds.
First, is it possible to modify the MOSFET booster to work with positive ground (i think i must to change the transistor, but i'm not sure)?
Second, the same question for  a FET buffer from http://www.muzique.com/lab/buffers.htm.
I want to do that because i want to put them both in the same box (and the same power supply) with my germanium Fuzz Face.

Thx a lot!

[Ben N]

As for the Mosfet Boost, I suppose you could substitute a BS250 (P-channel) and just plug it into -9V as is. As an added bonus, I recall Joe Davisson saying that P-channel mosfets are inherently less noisy than N-channel (right?). I can't speak to whether the tricks for running NPN devices with positive ground and vice versa are applicable to FETs (assuming they work right at all).
Ben

[Minion]

shouldn"t you be able to use N-fets with a Positive ground...i thought you can reverce Bias a fet as the Drain and Source are interchangeable??

[Sack Puppet]

The drain and source are sometimes interchangeable - in practice there might be a diode thrown across there or the channel width is different.

You can use p-channel FETs but it's not essential, the coupling capacitors isolate the stages and the low impedance of the power supply means that these circuits aren't really bothered what polarity "ground" is.

S.

[gigimarga]

it's possible to be so easy...only change the polarity?!!
what about the zenner...i must to interchange it or not?