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previous: AMZ The integral reverse diode (anode=s... -- 12/19/1999 2:31 PM view thread

Re: Mosfet Splatting

12/21/1999 4:35 PM
John Greene
Re: Mosfet Splatting
quote:
"What this boils down to is that as long as the gate of the mosfet is not connected to its drain, it is very unlikely that the normal mosfet diode will conduct and make a splatty sound."
 
 
I'm using what you consider the 'normal' diode and I use the germanium to keep the reverse diode from conducting. The 'normal' diode in this case has a much softer knee. In fact the sharpness of the knee is proportional to the transconductance of the MOSFET. I don't get any of the 'splattering' that is mentioned. It gets pretty grainy sounding when the battery gets low only because of the high threshold of the MOSFET diode. I use a germanium diode purposely to keep the threshold as low as possible. I measured a Vf on mine of around 1.4V.  
 
The distortion is extremely smooth without any hard 'edge' to it. Very tube like. Add a little gain in front, ala SHO, and you have a 57 Bassman on 11.  
 
--johng

 
Replies:
AMZ >>I use a ger... -- 12/21/1999 5:21 PM
aron >Very tube like. Add a little gain ... -- 12/27/1999 9:59 AM