Mosfet booster for P-channel mosfet?

[birt]

all mosfets i see used in boosters are N-channel mosfets. i'm looking for a clean booster (LOUD if possible) based on a P-channel mosfet. or is there some way to convert N-channel circuits?

[mjones99]

Joe davisson has a pmos booster

http://gr1ng0.tripod.com/Downloads/pmboost.zip

[birt]

thanks but the link doesn't work

[Seljer]

copy and paste the link into your browser's address bar

[WGTP]

http://www.diystompboxes.com/analogalchemy/pedals/obsidian.html

The Obsidian is essentially 3 Mosfet Boosts in series.   

[birt]

so if i look at the obsidian you could make it with n-channels too but you would need to switch the polarity of the caps?

[WGTP]

The caps and the power supply.  The N's, BS170 is the BS250 equivalent or 2N7000 may bias differently, as well.  Many N designs have a diode added to protect the Mosfet against damage from static electricity, but Joe didn't feel it necessary for the BS250's.  He also states they are quieter than their N channel counterparts, which is important when you have 3 in a row.